bleeding brakes

[eelvan]

Is there an easy way for a full bleeding and brake fluid replacement?
The reservoir is such a pain to open-fill-close-bleed- open-fill-close-bleed- repeat, repeat, etc.
It's impossible to see the level in the reservoir.
Can I leave the reservoir cap open while bleeding?
thanks

[Burntboot]

Sorry to say but there really isn't an easier way.
If you can't see the level of the fluid through the little window, that means the reservoir is caked in sediment.

It would be worth the time it takes to pull the cowl and service the reservoir.
It isn't just about being able to see the fluid level, the muck that is obscuring your view is the same thing, that when sucked into the bore of the master cylinder, can (will) cause damage to the seals and bore.

Putting the lid back in the master helps to reduce contamination of the fluid (it absorbs moisture) and the potential for spills.

I like to have a helper that pumps the pedal and replenishes the fluid regularly, like every 2 cracks of a bleeder screw.
Don't forget to bleed the LSP&BV

If you flush the fluid every 2-3 years, you'll avoid sedimentation and have much longer service life from the entire system.

BB

[timsrv]

I use the clear tube and the reservoir from my Mitivac (http://www.amazon.com/Mityvac-MVA6910-Fluid-Reservoir-Kit/dp/B007TMSPTU/ref=sr_1_11?ie=UTF8&qid=1427133718&sr=8-11&keywords=mityvac) to catch the fluid I bleed out. That reservoir holds 1/2 cup, which ends up being the perfect amount for the van. Every time that reservoir gets full, I know it's time to add more fluid to the van reservoir. Due to the fact brake fluid absorbs water, whenever I bleed, I also flush. I flush the system simply by doing an excessive bleed. I like to get at least a half cup of fluid from each bleed point on the van. If the fluid looks dirty, I keep going until it gets clean. As BB points out, flushing periodically and keeping the fluid clean protects the system from pitting and other issues. Tim

[P-rev]

I have a '95 s/c alltrac with 4-wheel ABS disc brakes. This van has been having issues so I've been getting things done to: A: fix the problem and B: rule it out as a future problem. So far I've cleaned the brake dust out of everything in all four wheel wells (hub, you name it), had all four rotors turned including the insides of the rears where the parking brakes engage, mainly because the left rear parking brake was sticking/brake light coming on. Even went so far as to apply a dab of drylube to the contact points on the e-brake shoes where they contact the rotor and hub. Replaced the front wheel bearings, both CV shafts and the four flexible brake hoses up front (two per side).

Now I'm trying to bleed those front brake lines and... it is not going well. I've gone through at least a quart (probably more) of brake fluid, to the point new fluid is coming out both of the bleeder valves... BUT there is a ton of air still in the system. I went back through checking that I had tightened all of the brake hose connections. I never disconnected the rear calipers, so no air back there. I'm stumped and willing to keep bleeding, but it seems like there must be an easier answer. I just don't know what it is!:hmr:

Thanks!

[timsrv]

Never put lube of any kind on brake friction surfaces! Hopefully I just read it wrong, but wanted to make sure you were aware of that. Moving parts on non-friction surfaces (like slide pins) should be lubed.

Bleeding brakes shouldn't be that hard. Of course you need a helper with some patience and the ability to follow directions. Just make sure your helper doesn't let up on the brake pedal until AFTER you get the bleeder port closed. For the fronts, they should be completely bled after about a cup of brake fluid (1/2 cup each side). Of course it's very important to not let the reservoir run low during the bleeding, or you'll have to start again.

When the air gets flushed out, the pedal will noticeably start firming up. How does the pedal feel? Spongy or firm?

If I was having an issue like yours, I'd probably bleed the backs too.............if for no other reason than to flush out the old brake fluid. Tim

[P-rev]

Thanks Tim, I put a dab of dry lube on 6 little spots (1/4"x1/2") on the sides of the e-brake shoe bodies (only, nothing on the brakes or rotors proper), not the e-brake shoe itself (of course) or any braking surface including the rotor. I did this because the parking brake shoes/parts had become very dry and sticking, so I cleaned everything and spotted those tiny areas with a little dry lube.

I have a cheapy suction device for one-person bleeding I've been using, closing the bleeder valve before losing pressure. I planned on bleeding out the old fluid in the rear brakes as well just haven't made it that far yet. The brake pedal still goes all the way to the floor. I pumped it a lot, but it never firmed up, despite a full reservoir and closed bleeder valves. Does it matter if the cap is off while I do this? I would think not, just trying to rule out variables. The reservoir fluid level never got too low. Never let the back pressure on the suction device get too low while the bleeder valve was open. I read on another thread that guys have had problems if the van was on ramps. My front end was on jack stands and a few inches higher than the rear, but not to the degree of being on ramps. So I changed out the stands to shorter ones to level it out (front wheels are off). It's been sitting all night and I'm about to go bleed 'em again. I'll let you know how it goes.

* it should be noted I began bleeding the brakes after replacing the two brake hoses on each side of the fronts, so there was a lot of brake fluid that needed to be added, fyi
still doesn't explain all the air...

[timsrv]

I wouldn't recommend using suction to bleed. Using a container with a hose is convenient as it monitors volume and doesn't make a mess. You are using a helper........right? No substitute for having somebody pumping the brakes and holding the pedal down while you open/close the bleeders. Tim

[P-rev]

It was definitely that suction bleeder tool (sounds like some medical device) giving fits. After I procured a helper to push the brake pedal, a couple pumps and all good. Thanks for the good advice Tim!

[timsrv]

:thmbup:

[saucymonkey]

I had a wheel cylinder go bad on my van and so I've replaced it and I'm about to bleed the brakes, but I also lost the clutch since the reservoir is shared and I was just wondering if there is any special order of events to bleeding the whole system? Does it matter which one I bleed first? And do I need to bleed the the load sensor as well? Thanks in advance.

[timsrv]

The clutch is bled from the slave cylinder and is bled much the same as the brakes. Have a helper pump the clutch then hold. While they're holding, open the slave bleeder port to relieve pressure, then close before they release. Repeat as necessary until you have your clutch back. Since you'll be right there at the slave, you'll be able to observe movement and it should be easy to tell if/when you make progress. I don't know how much (if any) relevance there is to the following, but I've heard members complain more than once that clutch bleeding is much more difficult (even impossible) with the front of the van elevated (ramps). For this reason, I would recommend making the van level before attempting to bleed. If you initially have trouble bleeding the clutch, a suction tool may be useful at the slave just to get things moving. Once fluid starts to flow, revert back to standard bleeding as described above.

When it comes to bleeding brakes, I very rarely bleed from the LSP&BV, but I've read reports from others saying it's necessary. If I ever had a problematic bleed I wouldn't hesitate to bleed from there, but perhaps I've just been lucky so far. Regarding the LSP&BV, it is a restriction and can be an issue while bleeding. For this reason, when I bleed the backs, I usually disconnect the arm from my rear axle and lift it up until upward travel is maxed out. You can either prop it up or wire it to the under body during the bleed. Brake bleeding can be accomplished without this step, but more flow equals an easier bleed. If you don't disconnect the arm, at the very least, make sure the weight of the van is supported by the rear axle. If the axle is unsupported (hanging), and the arm is still attached to the axle, you will get almost zero flow through that valve. Tim

[saucymonkey]

Thanks for that info Tim, I was successful bleeding the brakes I think but I still have no clutch slave action. I'll try a suction tool but now I'm worried that I have two problems because from what I can tell the slave should push the clutch fork away but the fork has zero pressure pushing forward. If I compress the slave piston, the fork is limp. Is that normal or does that mean I have deep internal transmission problems? :cnfsd:

[timsrv]

I don't know as I don't have a clear mental picture. It seems too much of a coincidence that something else just happened to break the same time the reservoir went empty. If the clutch master and slave are working, there should be movement there. I would guess you've probably got an air bubble inside the clutch master cylinder. Try the suction tool, bleed the system again, and report back. Good luck. Tim

[Sir Goofy]

Don't know if I missed it but is there a step by step tutorial on bleeding brakes? If someone has a link that would be appreciated.

[timsrv]

I did a quick search for you and found 3 threads that have good information on the subject:

http://www.toyotavantech.com/forum/showthread.php?127-Load-Sensing-Proportioning-Valve-and-Bypass-Valve

http://www.toyotavantech.com/forum/showthread.php?3804-Bleeding-the-brakes

http://www.toyotavantech.com/forum/showthread.php?1804-New-owner-87-4x4-5spd

There are more but these are the most informative. Don't forget there's a search box in the upper right corner of each forum page. I know our search feature isn't the greatest, but I've found you can do a Google search by typing in your terms along with "toyotavantech.com" and that works well. Good luck. Tim

[Ace MM]

... BUT there is a ton of air still in the system.
I never disconnected the rear calipers, so no air back there. I'm stumped and willing to keep bleeding
Air can get trapped in the rear line, that why the farthest is the place to start.
I used to bleed my 4runner with ABS, with the motor running... read about the pump helping.

For the clutch, have the pedal depressed and held while bleeding. I had a helper not do that and it took a full bottle to get all the air out.
Release the pedal slowly between pumps to draw fluid in and sometimes you can see the bubbles released.

[timelessvehicles91]

I use the clear tube and the reservoir from my Mitivac (http://www.amazon.com/Mityvac-MVA6910-Fluid-Reservoir-Kit/dp/B007TMSPTU/ref=sr_1_11?ie=UTF8&qid=1427133718&sr=8-11&keywords=mityvac) to catch the fluid I bleed out. That reservoir holds 1/2 cup, which ends up being the perfect amount for the van. Every time that reservoir gets full, I know it's time to add more fluid to the van reservoir. Due to the fact brake fluid absorbs water, whenever I bleed, I also flush. I flush the system simply by doing an excessive bleed. I like to get at least a half cup of fluid from each bleed point on the van. If the fluid looks dirty, I keep going until it gets clean. As BB points out, flushing periodically and keeping the fluid clean protects the system from pitting and other issues. Tim


Is there any pictures on how to bleed the brakes? I don't understand What anyone is saying on here.

[timsrv]

There's lots of videos on youtube showing how to do it. I watched a few only to realize I'm pretty set in my ways (had a hard time agreeing with everything I saw), but thought these guys did a pretty good job: https://www.youtube.com/watch?v=lPwM2vn3bT0. I have a rule for bleeding though that they didn't do "The bleeder should only be opened while the pedal is being held down, and the pedal should never be released until the bleeder is closed". Evidently their way works, but IMO opening that bleeder when there's no pressure could result in air entering system. If the system is pressurized before opening the bleeder, then it's a one-way street.

Using the same principals they did, I'll have my helper pump the pedal 3 times, then hold & call-out "holding" (while keeping constant downward pressure on the pedal). That's my signal. When I hear the word "holding" I quickly open & close the bleeder. There is a little surge of fluid/air each time the bleeder is opened and closed. When the bleeder is securely closed I say "release" or "again" and the sequence is repeated. I use a clear tube going to my drain bottle so I can monitor for air bubbles and view fluid color. As stated in that video you should start with the bleed point farthest away from the master cylinder. If you've changed calipers and/or wheel cylinders sometimes it can take a while to get things moving. If I can't get flow on one wheel I'll move to another and then return later to the one giving trouble. Bleeding brakes shouldn't take more than a few minutes, but I've had stubborn bleeds take as much as a half hr. If you let the master go dry, you'll need to start over.........so keep an eye on the reservoir level.

When replacing a master cylinder on most vehicles I'll "bench bleed" before installation. To do that I put the master in a vice, put brake fluid into it, then actuate it (push the plunger) until fluid starts squirting out of both outlet ports. Due to the van's set-up (external reservoir) this is a bit more challenging. For the van I'll usually install the master, fill the reservoir, Then pump the pedal to establish flow before hooking up the outlet lines. If you have a Mitivac, that could be used to suck fluid from the reservoir via the outlet holes before hooking up those lines. Either way, should work, just make sure the master is full and pumping before those outlet lines are connected (or it can be a PITA getting the air out of the master). I'm sure there's also "bench bleeding" videos on youtube. Good luck. Tim