Replacing your van's thermostat [Archive]

rockstacker

04-24-2015, 01:33 AM

I'm sure that mechanic has more knowledge and is better educated than the Toyota engineers who designed it to be there. After all, he has risen to the lofty position of "mechanic" rather than waste his time as a lowly engineer :rol:. Just my $.02 :wave1:
"Eh, you don't need that part. Let's also drill some holes in your shocks to reduce weight and increase performance. Also, if you paint this van red, it'll go faster.":LOL2:

ratatouille

04-24-2015, 05:05 PM

Get what you guys are saying thanks. I am interested though in the this jiggle valve and purpose behind it.. The van this work was done on is still getting hot, only on inclines. (well above half way mark) then goes back down. Even after new radiator, fan clutch, hoses...head gasket was replaced after blown.. flushed..etc. This is an 89 automatic camper conversion. I recently (2,000 miles ago) did a cooling system overhaul on my 88 4wd manual, and did not remove the jiggle valve, and I haven't seen the temp needle go above 1/4 even on steep terrain (I love hearing that fan roar when it does get warm...) ....I wonder if the valve really does make the difference?...

timsrv

04-25-2015, 12:40 AM

Jiggle valve probably doesn't do a whole lot, and I do believe it's there to help purge air from the system. The manual is specific on it's placement & since it's easy to install @ 11 O'Clock, I figure why not? I'll be the 1st to admit there's a whole lot I don't know, so why not rely on the judgement of the engineers? Just seems arrogant to dismiss their judgement and disable functions of expensive OEM parts. Tim

Suzu

05-27-2015, 07:46 PM

Where are the Preston Gen-2 t'stats sold? Anyone know the part #?

If this part can't be found, is OEM the next best thing?

timsrv

05-27-2015, 10:42 PM

IMO, OEM is the best, but the Prestone one didn't create any adverse effects (like some do), so it was acceptable. As far as I know, Prestone stopped making those about 6 or 7 years ago. The correct part number for the van was 761-180. There's probably still some hanging around in a warehouse somewhere, but I'm thinking they'd be hard to find. Toyota part number for this is 90916-03069 (http://www.toyotapartsdeal.com/oem/toyota~thermostat~90916-03069.html). Don't forget the gasket/seal, it's Toyota part #16325-63010 (http://www.toyotapartsdeal.com/oem/toyota~gasket~water~inlet~housing~no~1~16325-63010.html). Tim

Suzu

05-28-2015, 08:30 PM

Thanks, Tim.

Do you happen to know if the OEM gasket is interchangeable with any of the aftermarket gaskets?

timsrv

05-29-2015, 03:06 AM

Yes, I've used Stant #27280. I'm sure there are others. Tim

Rufus

01-17-2016, 11:22 PM

I'll be damned if I didn't read this thread AFTER I installed my thermostat. My factory service manual showed up on the mail yesterday but I didn't bother to consult it either. I am such a failure. I have never heard of a "jiggle valve" so I went to the manual and lo and behold, there it is. So at 7pm in the rain, in the dark, in my pajamas, there I was tonight pulling my van onto the ramps and removing the thermostat housing to check the new thermostat. One hour later I was done and taking it on a test drive. I felt like the dad in A Christmas Story when he gets a flat tire and tells the mom to time him. Pretty quick for a radiator drain, t-stat remove and replace, and radiator refill if you ask me. After all that...this thermostat didn't have a jiggle valve. Oh well, I can sleep tonight without that keeping me awake.

timsrv

01-18-2016, 03:51 AM

After all that...this thermostat didn't have a jiggle valve. Oh well, I can sleep tonight without that keeping me awake.

Are you saying you didn't use an OEM Toyota T-stat? Me and a few others here have spent countless hrs chasing down hot running issues, only to find out the new T-stats we installed actually were the issue. For some reason not all T-stats work well in the van. I know it sounds odd, and I refused to believe it when others claimed it, but I got burned on this one too. Since then I will only use OEM Toyota T-stats on the van. Hopefully you lucked out and got a good one. The one that burned me was what Napa gave me after I asked for their "Premium quality" T-Stat. It was a Tama Enterprises Co. Part #154-2403 "made in Japan" & even had a jiggle valve. Tim

Rufus

01-18-2016, 08:39 AM

I did not use an OEM thermostat. Unfortunately I currently live in Podunk Skunkpatch, California and the nearest dealer is 40 miles away. If this thermostat gives me issues I will go with OEM.

timsrv

01-18-2016, 12:24 PM

That was similar to my issue. I actually had a new OEM one here (someplace) but had recent moved & couldn't find it :doh:. Of course I didn't start looking until I had the old T-stat out. You'd think that it wouldn't matter, and in most cases it wouldn't. In my case it was sort of "okay", but at times my temperature would get very close to the danger zone. It was like my radiator was clogged or the fan clutch wasn't working at full efficiency. Eventually I went full circle and replaced the T-stat (again) with OEM. It actually surprised me when that remedied my problem. It's weird how these things can be so quirky sometimes. All things considered, I would say odds are in your favor that the t-stat you installed is fine. After my experience I tend to be a little superstitious about T-stats. Tim

Rufus

01-19-2016, 12:06 AM

Well I plan on replacing the power steering pump in the next couple of weeks and that will be the prime time to swap the thermostat. I will be putting an OEM T-Stat in at that time.

K0ZLU

04-29-2016, 03:43 AM

Well I plan on replacing the power steering pump in the next couple of weeks and that will be the prime time to swap the thermostat. I will be putting an OEM T-Stat in at that time.

From how it was explained to me, the Toyota OEM for our vans are designed to work with horizontal flow, while most others are designed for vertical flow. Having changed thermostats in other vehicles, but not thinking about the flow while doing so, and now thinking back, they were all used vertically. My '89 4x4 was running hot and I know it doesn't have the OEM t-stat because I helped with the motor swap 5 years ago - I did n't own the van back then nor know about using OEM t-stats, just got her in March. I also have the water pump and fan clutch just in case. It got close but I was able to baby her with the idle carrying my at that speed. Didn't go far and had to keep letting her cool down, but I made it to where I got a u-haul car hauler and a buddy met me with his truck.

timsrv

04-29-2016, 04:18 AM

Canoed_son

10-11-2016, 04:13 PM

these t-stats are also on the suction side of the water pump. Most other vehicles have the thermostat on the output side of the pump. Not sure how much difference that makes, but there it is. BTW, that doesn't look like a good spot for overheating :no:. Tim

Tim, I recently was replacing the lower rad hose (that connects to the T-stat housing) and ending up spilled some (not TOO much) coolant on the alternator....from what I've read online in other forums its not the worst thing in the world. However, I noticed you mentioned earlier in this thread that this caused someone to replace the alternator. I was wondering if there was anything that could be done to ameliorate the issue without having to replace the alt....i have already rinsed it with a liberal amount of water and dried what I can with towels....let me know your thoughts.

timsrv

10-11-2016, 10:08 PM

It's not the worst thing. Our alternators are sensitive, that is certainly true. They are however built to put up with occasional water intrusion. They don't like prolonged exposure to power steering fluid (ATF) as that gums up the brushes. I would think antifreeze is not as bad as ATF, but probably worse than water. If I got antifreeze in mine I would rinse with water (like you did), then forget about it. Nothing more you can do anyhow, so no use worrying about it. I'm guessing there will be no long term ill effects. Tim

PS: Next time put some plastic over/around your alternator to avoid exposure.

Rossi_46

03-21-2017, 03:18 PM

Rudy

03-21-2017, 03:25 PM

Woah, dude! Good thing you are getting at it. Wow.

Rossi_46

03-21-2017, 03:35 PM

The vehicle is a one owner from new, I think the mechanic might be a bit suspect. He's apparently looked after this vehicle for her and after a brief chat he never called me back about doing the work in now doing.

Hopefully it'll be running today and I'll see how it goes. Fingers crossed!

Mfry

03-22-2017, 11:00 AM

Just did my thermostat and the back end was broken off and I had to fish it out with a magnet. That's what time and intense heat does, I guess.

JPERL

03-22-2017, 11:45 AM

I'm replacing a water pump, hoses and my T Stat. One on the left was what the PO gave me as she said her mechanic had changed the thermostat. The one on the right is the new OEM one, the one in the middle is what I've just pulled out!

I'm worried

By design you cannot really run with out a thermostat as it is the thermostat that also creates the seal and without a thermostat you would have leaks. The suspect mechanic looks like he destroyed the thermostat just leaving the part that creates the seal to simulate having no thermostat installed as to not address the real issues of overheating .

Rossi_46

03-22-2017, 01:02 PM

Hi, yeah I think it was done on purpose. I took the new one off to see if anything was left in there and it was clear of any parts. I've replaced upper and lower rad hoses, water pump, gaskets and I'm going to flush the radiator to get all the crud out. Fingers crossed!

JDM VANMAN

03-22-2017, 04:29 PM

About 3 years ago I found a great cargo conversyion van that was done up really nice inside but there was difinately something shady going on with the temperature gauge, it didn't move and there was no heat after driving it for 30 min.

I took it to my trusted Toyota MasterTech (now retired) for inspection and he caught all those mechanical issues and told me some people take out the thermostat in order for it to run cooler or something like that, I still wanted to get it but he stopped me from taking the chance. Maybe a good thing in the end.

JDM

Dogfish

03-22-2017, 09:52 PM

Strange... I can't imagine anyone doing that on purpose, when you can just leave one out if you choose.

I took one out of a '63 Plymouth one time. It was the middle of a snowstorm... halfway across Pennsylvania and another 6 hours to get home. Water pump broke but without the thermostat the coolant would still circulate. It was hot but I stopped every hour or so.

I would be suspect of pieces... somewhere.

If you can find the mechanic from the PO I would call him on it. I really would be amazed if he did it on purpose.

-Jim

Chardog1971

03-23-2017, 11:55 AM

on this engine you have to have at least the outer ring of the t-stat to attach the O-ring. otherwise water, water everywhere. I have seen people drill 1/8" holes on the flange to allow some coolant passage when t-stat is closed. Agreed, looks like some one modified the ring to bypass t-stat.
I have an 89 that uses coolant. the PO said if you fill the reservoir, it will boil off untill it reaches a certain level, then it stays constant. Heat works fine. No leaks. No bubbling from the over flow. Temp within range. After a few 1000 miles the heat starts to not work so well. Still running in the safe zone on the gauge. Add some coolant and good to go for another few 1000. apparently this has been going on for the 10 years he had the van. He has had a couple of mechanics look at over the years. No one can figure out whats up, as of yet. It's more of an inconvenience than anything but, I'd like to fix it.
I assume during the investigation, someone checked the T-stat. The pump and radiator must be OK, or I'd have overheated, right? Both front and rear heaters work, so thats not it. Once I fix the u-joint on my 87, I will investigate further.

Always thankful for this wealth of information:redvan::yellowvan::greenvan:

bobby

05-19-2017, 12:31 PM

I just dealt with a high temperature issue with my 1989 Van. It never got as hot as the one pictured but about 70 to 75% on the gauge though. I turned the heater on and it got me down about 50 to 60% so I knew that I had some flow through the radiator. I took it to a radiator shop in Santa Ana , Calif. I had been to two other radiator shops and got quotes. First one told me that a rod out of the radiator would not work, and the second one gave me a quote of 350.00 to rod it out. Our good friends at B & G rodded it out including labor for 150.00 He told me that it was 40-60% plugged. He showed me that the fan clutch was needing relacement and submitted to his judgement. He also replaced the lower radiator hose as it was cracked and old. I had replaced the upper radiator hose a week prior. He told me that there was not a thermostat in there, and because I know everything, I told him to let it go, because I figured I didnt need one in southern Cal because it doesnt freeze much and it gets hotter than most places. That was a big mistake I think. After all of those repairs, new fan clutch, new lower radiator hose and the rod out and coolant it was 266.00 can you believe it. What I cant believe is how long it takes to warm up now, and it barely reaches 1/4 on the gauge. Too good to be true in my opinion. Because of that, I am going to put the thermostat back in. I will be going with an OEM one if I can find it. Thank you guys for all of the help you provide. This is definitely a plug for B & G radiator in Santa Ana, Calif in Orange County. Two brothers that have been there for over twenty years, Clean shop, nice, honest and reliable:wave2:. Refreshing
thank you,
peace,
bobby

timsrv

05-19-2017, 01:21 PM

That's a good story. I read the beginning anticipating a rip-off and/or bad ending. Glad you found those guys. Sounds like they did the right things and charged a very reasonable price. And yes, I would recommend installing an OE thermostat as soon as possible. Toyota intended there to be a thermostat there. Without it you are lacking restriction. Restriction can be necessary to promote equal flow to all parts of the engine. Since the coolant will take the easiest path, unrestricted flow could result in over cooling of front cylinders, but reduced cooling to the rear (true on some engines, not sure about the 4y). Also, since the engine is designed to run @ ~180 deg, most engine wear occurs during warm-ups and/or overheating conditions. Running your engine below 180 deg long term will likely shorten engine life. Tim

TheCrippler

05-19-2017, 08:05 PM

I recently replaced the thermostat on my 89 townace. Thought I'd mention a couple of things unique to the diesel townace that I learned along the way.

Thermostat is in the same spot, but the alternator and the AC are flip-flopped. The thermostat housing on the 2C-T is sitting over the AC compressor. I still drained my coolant but much less of a worry when it comes to spilling.

The space is tight and it was horrible to get the bolts back in on the housing, I had to feel around for 30 minutes to get the housing aligned and the bolts in.

My thermostat was stuck wide open and the van was running cold all the time. This was causing the temp-sensor for the glowplugs to keep sending juice to the glowplugs so I kept prematurely burning them out. They are expensive so this sucks. I thought I had a bad glowplug controller but the van was just running in "warm-up" mode for extended periods of time. After I replaced that thermostat the van warms up much quicker, stays at the right temp 100% of the time and I'm not burning out glowplugs :) Maybe this was a combination of colder weather and stuck thermostat that was causing the sensor to read wrong?

BigDawgGottaEat

05-21-2017, 12:59 PM

I was just about finished replacing my thermostat when I snapped off the lower stud. Wondering the best way to proceed here. Anybody know if it is threaded and could be dealt with similar to the exhaust manifold studs? Seems like it might be cast into its home, maybe I could drill it out and tap it for a bolt? Third option I have been thinking is replace the whole part, am I correct in thinking this is the water pump housing? Any guidance much appreciated.
5372

Edit: I think I just answered my own question, but maybe my post will help another unfortunate soul. Found this picture of the "Timing Gear Cover and Rear End Plate". Looks like the studs are threaded, so I guess that is good news? I think I am going to be down in that hole for a long time.
5373

timsrv

05-21-2017, 01:35 PM

It's a steel stud (Toyota part #16194-71010) that's threaded into the aluminum timing gear case. It looks like there's enough of it sticking out to give you a fair chance of easy removal. If I were in that spot I'd apply heat to the stud (carefully avoiding direct heat to the aluminum housing). I'd use an acetylene torch with a focused tip and get the stud glowing red, then wait for it to lose the red glow and immediately try to remove it with a vice grip (while it's still hot).

These studs were put in tight with some sealant and/or Locktite type material on the threads. Heat applied correctly to the stud will weaken that bond and the expansion/retraction of the steel & aluminum should allow for easy removal. As always, when using a torch, do so in a well ventilated area. Be very careful when using an open flame around fuel lines and make sure there's no gasoline or other flammables in the immediate area. Also make sure you have the proper type fire extinguisher handy. If you're not comfortable doing this yourself, call your local parts store and/or weld shop and ask if they know of a local guy who extracts broken bolts/studs. There's usually a mobile guy in most areas who will come to your location and is capable of some amazing things. Good luck. Tim

PS: I'd take that spacer plate off before attempting stud removal.

Ace MM

05-26-2017, 01:42 PM

I'm sure that mechanic has more knowledge and is better educated than the Toyota engineers who designed it to be there.
Toyota did not design the jiggly valve. Its for air removal.
I've removed them from any thermostat for additional flow(only takes a little longer to warm up)
On high rpm cars, I've opened the hole as well, in case of cavitation.

I'm about to do this, and coolant flush on my hiace as the trans doesn't cool down very well once heated up.

tennesseetoyota

12-27-2017, 03:15 PM

So I'm working on replacing my thermostat and for some reason the housing will not come off. I've removed both 12mm nuts, yet the housing doesn't want to slide off. Any suggestions?

Thanks!

timsrv

12-27-2017, 03:42 PM

Tap it sideways with a hammer.

tennesseetoyota

12-27-2017, 04:17 PM

Yeah it was just a good bit sicky. Thanks!

AD2101

06-15-2018, 12:18 AM

Just another preaching to the choir here about only using OEM Toyota for the thermostat. My 86 started running hot (3/4 up the gauge, not the end of the world but higher than it should be running) once the ambient temperature got towards or past 100 degrees outside. Not knowing the age of the coolant or what thermostat was in it, I did a patented ChrisFix super flush (https://www.youtube.com/watch?v=s--5ft5YiHg) (lol), replaced the fan shroud (old one wasn't properly seated against the radiator all the way around, plus the ears had snapped off) and pulled the old thermostat.

The thermostat was obviously very old, the part number I pulled off came back as a Robert Shaw branded thermostat. They apparently still make home thermostats, I have no idea if they still make ones for cars though, this particular one had no jiggle valve and was just closed all the way around. It was likely in there since the first Bush was president so it wasn't terrible but was in desperate need of replacing.

Anyways, I just got back from running some errands and the needle has yet to go past 1/4 of the way up the gauge! I'll put some miles on it in traffic and 105 outside just to be sure but it's amazing how much of a change these little thermostats have on our vans. :dance2:

Gambit

07-17-2018, 05:55 PM

Can someone point me in the direction of the coolant block drain plug? Thank you!

Burntboot

07-18-2018, 08:00 AM

Behind the alternator, tucked in by the engine mount.

timsrv

07-18-2018, 12:26 PM

I used the search feature and found this:

https://www.toyotavantech.com/forum/showthread.php?1266-Coolant-Reservoir-Leak

Gambit

07-18-2018, 12:38 PM

I used the search feature and found this:

https://www.toyotavantech.com/forum/showthread.php?1266-Coolant-Reservoir-Leak

Thank you both - I went through a ton of threads and missed that photo.

timsrv

07-18-2018, 02:06 PM

No problem. I had an advantage since I posted it (I knew it was there)......I could also remember some key words (like "brass" and "extension"). Those two coupled with "block drain" narrowed it down to just 2 threads :wnk:. Tim

armorrell

01-04-2019, 07:31 PM

Lots of great info here... I just wish I'd read it all first.

A month or so back, when making preparations to do a complete coolant line refresh, I went to RockAuto.com and punched in my search for the appropriate thermostat and gaskets. (1988 4WD Manual)
Of course, NOW I'm reading all of this about the OEM parts and regret my purchase.
Now I'm ready to replace the old TStat and upon opening the box and inspecting the new one, I find it doesn't have a jiggle Valve at all. :wall:

So.. do I take a chance? Or do I order it all again from Toyota?
here's the link to the particular TStat I ordered. https://www.rockauto.com/en/moreinfo.php?pk=366272&cc=1279818&jsn=388

Opinions?
Anyone installed an aftermarket TStat manufactured without a jiggle valve to any success??

I know the original article (( https://www.toyotavantech.com/forum/content.php?199-Replacing-your-van-s-thermostat )) was from 9 years ago and wondered if anything would have changed since then.

PNW vanwagon

01-04-2019, 08:18 PM

IMO i'd only use OEM since it's still available and cheap and it's specifically built to get your vans cooling system running right. but since you already bought one you can try it and see how it runs. the install is a PITA but only takes an hour or two max - so you can always swap out later if the temp isn't running within the optimal zone. other consideration is if you want to risk your van running too hot or how far from civilization you typically drive. on second thought after typing all this out - i'd just buy the proper thermostat and be done with it

llamavan

01-04-2019, 11:01 PM

armorrell

01-05-2019, 12:16 AM

Just. Buy. OEM.

If you can't afford to eat the cost of that aftermarket t-stat and wait a for the proper OEM one to arrive, you're really really really not going to be able to handle the cost of a head job plus how long that puts your van out of commission.

Gwen
Totally agree Gwen.
Small price to pay to put Crusty back on the stands. After just replacing all the coolant lines, water pump and coupling, valve cover and such. I’ll happily get the OEM TStat to finish it up proper rather than take a chance.
Thanks for the guidance and patience. It’s much appreciated.
A

armorrell

01-07-2019, 12:07 AM

The diagnostic proved true. (Upon cranking the van- coolant was immediately circulating) So it seems the TStat was stuck open. That’s exactly what I found when I pulled out the old one.

The only bad thing is the lower right stud on the TStat housing unscrewed from the block and came out with the nut when removing it.
I didn’t drain the block, so there’s still some coolant inside dampening the threaded stud receiver. Because of not being able to clean out the coolant where the stud gets screwed back in, I didn’t bother putting threadlock back on the stud. Instead I just screwed it back in to hold the housing and TStat in place overnight.
Now I’m not exactly sure what to do to lock in that stud when I finish up tomorrow.

Burntboot

01-07-2019, 09:27 AM

At this point I wouldn't worry about that stud.

Nuts often weld themselves onto studs. the proper way to deal with it is to separate the 2 when they are out and reinstall the stud, then secure it with the nut.
Installing studs is usually done with a double nut and thread locker isn't usually required.

The way you have done it should work just fine, the only time one would have to worry is if the new gasket were significantly thinner than the old (if the stud shaft were to bottom out prior to the nut flange making contact)

Best practices would say do it right, but as you've already "got 'er done" just make a mental note for next time.

Burntboot

01-07-2019, 09:31 AM

armorrell

01-13-2019, 07:22 PM

And if I read that wrong and it isn't fully assembled yet, then extract the frozen nut, clean up threads (block and stud) and reinstall stud (double nutted) and torque to spec, then remove the double nuts and proceed as normal.

Thanks for the input- I got everything back together without any thread lock. The bolt sealed itself when torqued down and it's been running like a champ ever since. Appreciate all the help in getting this project done!

stillgoing

01-17-2019, 11:04 PM

Just a little FYI. Any time I remove a nut from a bolt or stud I put a little bit of anti seize compound on the threads to help in the removal of the nut down the road. Nothing worse then a nut that gets frozen. If it gets stuck on a bolt and you break the bolt it can be replaced but break a stud SOB. Also if you wanted to use loctite to reinstall that stud just get a can of brake cleaner and spray it on the inside threads. It will clean the slime of the A/Freeze off and it dries super fast leaving a clean and dry surface for the loctite to work like it should.

Flounder

01-21-2019, 06:37 PM

FWIW, brother-in-law (professional mechanic) and I replaced my '88 2WD 5spd's thermostat several weeks ago. The next day I drove her close to 200 miles in Florida heat without any problems whatsoever. New thermostat is OEM; I always buy Toyota when it's available.

MyToy

07-08-2019, 05:20 AM

Anybody ever notice that the Tstat housing has a slight turn to it?Here is a pic of the turn.

Service manual says nothing as to which way it goes in.

Does it matter?

MT

timsrv

07-08-2019, 04:13 PM

That's so it won't interfere with the alternator adjustment bracket. If you try to install it with the alternator already installed, it will be obvious which way it needs to be. Tim

MyToy

07-08-2019, 04:23 PM

Roger that. It was on backward then. OMG, it is amazing this little 4Y ran as good as it did with wrong torque values on the head and manifold.

Thanks, just waiting for the next shoe to drop:dizzy:

MT

bushcat

07-20-2019, 09:46 PM

So, my van overheated. Blew the radiator hose off near where the lower radiator hose goes into the radiator. Going through the checks to see if it is something besides the headgasket. New thermostat, new water pump, new fan clutch, new radiator cap within the last two years. Anyways, I pulled off the thermostat and tested it and it does pop open. I'm going to put it back in place but I have a question. I'm wondering if you have to use a gasket for the thermostat and for the thermostat housing. I did both before but I don't see it in the instructions.

Do I need to use this (https://www.rockauto.com/en/moreinfo.php?pk=120661&cc=1279728&jsn=1032) water outlet gasket along with the thermostat seal?

If the water outlet gasket is needed as well, I'd suggest adding it to the instructions.

Thanks!

llamavan

07-21-2019, 12:29 AM

No need to use a gasket other than the rubber gasket on the t-stat itself, and Toyota does not call out for another one in the EPC, either. The number given on Rock Auto (1634171010) is the number for the "water inlet" (t-stat housing) itself (!).

Gwen

bushcat

07-21-2019, 12:41 AM

Thanks Gwen, I wonder if that could cause an overheating issue if I used both and the paper one deteriorated (the housing one). There wasn’t really a leak though. Hmm, ok good to know. Thanks for the info. Will install with just the OEM gasket for the thermostat.

Yahshoor

08-29-2019, 01:12 PM

Are most of the pics in the thermostat replacement guide of the 4WD? I suspect that this is a picture of the 2WD, because I'm working on a 2WD and I think I have to remove the part circled in red here:

9248

in order to remove the tstat housing.That hard line leading from the power steering pump is in the way on the 2WD, so I should probably... drain the PS pump and remove it to get access to the tstat? Or ought I be able to remove the housing with that line still in place?

timsrv

08-29-2019, 02:41 PM

Toyota has at least 3 different versions of that PS hose (2wd & 4wd), so there's always going to be a variable there. I still don't think you need to remove it though. If you pull the coolant recovery tank there should be enough room to access the T-Stat. Removing that PS line would be nice regarding T-stat access, but maybe not worth the mess and/or the risk of creating a leak there.

BTW, the recovery tank is removed by simply pulling up on it. It can get stuck pretty tight, but if you wiggle it back and forth while maintaining a constant upward force it will pop-off the mounting bracket. Tim

Yahshoor

08-29-2019, 03:22 PM

Thanks, Tim! I managed to get the thermostat housing off without any PS disassembly. There was just enough room in the elbow of the power steering line to get the bolts off, one. click. of. the. ratchet. at a time. I also discovered that I really, really need 2-inch and 4-inch extensions to go with my 3-inch extension, if I hope to get it back on.

Also, I heeded y'all's warning and bought OEM replacement parts. Check out what I found inside:

9249

Obviously the previous owner didn't understand the importance of using... OEM zipties. :dizzy:

timsrv

08-29-2019, 05:05 PM

LOL, he obviously had more knowledge than the engineers who designed it. Hopefully there's no duct tape or bailing wire elsewhere in the system :rol:

Yahshoor

08-29-2019, 07:37 PM

What are the symptoms of an improperly seated thermostat? Or perhaps of a thermostat where one over-tightens the bolts and squishes the gasket? It overheats faster, now that I have replaced the PO's zip-tie themo-hack with OEM thermostat and gasket.

timsrv

08-29-2019, 10:05 PM

There is likely another issue that's causing the overheating. The PO probably wire tied the old one to keep it open. All that did was delay the inevitable. Putting a new OEM one in was the right 1st step. If you botched the replacement job it would most likely be leaking. Since it's not, then I'm guessing that part is okay. There are other threads on here to help you troubleshoot an overheating issue. I would recommend doing a search reading some of those threads. If you still have questions after doing that please post in one of those. Good luck :). Tim

extempo

04-21-2020, 12:09 AM

Can anyone tell me about the bolt circled in this image? I was changing out the thermostat in my 86 cargo van today, and I mistakenly removed it instead of one of the nuts for the thermostat housing. Luckily I had removed the alternator, so it didn't get doused in coolant.

Did I really screw up here, or can I just tighten the bolt back down and be on my merry way?

I'm also doing the water pump and fan clutch while I'm in there.

10123

timsrv

04-21-2020, 01:14 PM

That's an adapter plate of sorts that transitions between the timing cover and the t-stat housing. Just taking the bolt out then putting it back in shouldn't cause a problem. I would however recommend you keep an eye on it when you do your initial start-up/warm-up to make sure it's not leaking. Tim

extempo

04-21-2020, 02:05 PM

That's a huge relief, thank you Tim. :thmbup: I also have some black Permatex gasket goop, and could pull the spacer plate and re-gasket if that's a better bet.

timsrv

04-21-2020, 02:18 PM

I don't know........I really don't like gasket goop, at least not by itself. If you mess with that plate enough to separate the gasket, then I'd recommend a thorough cleaning, new gasket, and a little bit of Toyota FIPG on each side of the new gasket. There's no guarantees, but if all you did is pull the bolt an reinstall, I find it hard to imagine that in itself would create a leak. Tim

extempo

04-22-2020, 01:44 AM

I just tightened the bolt back down without fussing about it. The old thermostat was not the Toyota part. I replaced it with the Aisin one from rockauto, along with the Aisin water pump and fan clutch. Before, my temp gauge normally sat around half or just above and would climb on the freeway and uphill. I’d have to crank the heater to bring it back down. After finishing up the work today, the temp gauge was hanging out in the lower third for normal driving, and only climbed to just under half way cruising up a big hill near me, without the heater running.

I’m a happy camper, and hoping not to find any leaks tomorrow. I could not have done it without the help of this forum, so many thanks.

thevanburenbys

02-02-2023, 04:52 PM

I could really use some advice on how to access the radiator drain valve on my 87 4wd.

I've been rolling in the ice and mud for the better part of two hours and cannot find this thing for the life of me. Should I need to remove the fan shroud? It does not appear to be anywhere on the bottom of the radiator...

Should I access through the passenger side wheel well? I removed the plastic in there and still can't see the plug.

Please help if you can, thank you

timsrv

02-03-2023, 02:59 AM

Here's a quote from another thread:

There's a petcock on the passenger side bottom of the radiator & a block drain on the driver's side front of the engine (see pics below). The radiator drain is easy enough, but the block drain is a PITA (even worse on a 4wd). It can be done though. I semi-regularly take this drain out on both 2wds & 4wd vans (yes, with the engine installed). Having a specific length socket & extension is critical. I usually grab a good selection of extensions & have a deep socket & a regular one when I do it........then the 1st couple of minutes is determining what combination will work. It's a 14mm head. One of these days I'll document the specific socket/extension combo so I don't always have to re-invent the wheel. I should also mention to use a 6 point socket as the plug is brass & easy to mess up. Try to keep your drive angle straight while removing & installing. Tim

https://hosting.photobucket.com/images/a23/timsrv/(edited)_IMG_4482.png

https://hosting.photobucket.com/images/a23/timsrv/(edited)_IMG_1851.png

If the radiator has had a new core installed, some radiator shops will remove the stock drain, but they will usually replace with another type in the same location. If for some reason yours doesn't have one, you could always just pull the lower hose off the radiator. Just have a big drain pan ready and some kitty litter as it will empty very quickly and probably splash out on the floor. Tim

PS: Assuming it's stock, you do not need to remove the shroud, but it will help if you remove the plastic splash guard below the drive belts. The drain plug is white plastic and is on the passenger side facing towards the back of the van. There is a little nipple below the plastic knob with a short drain tube on it. To drain just loosen the plug by hand until coolant drains from the little hose. Loosen the radiator cap so air can displace the antifreeze as it drains.