bypass heater lines, safe?

[davidgracevan]

-i live in a very tropical country, vehicles here doesn't come with heater. i own a 88 A/T van and the hoses that goes to the heater cores are starting to leak. is it safe to just remove all of the heater hose lines?... bypass them?... and just plug the the metal tube beside the block, at the front and the small tube behind the cylinder head?... what could be the effect of what i'm thinking to the engine's cooling system?

[timsrv]

Engine won't care. If you take a section of 5/8" heater hose and make a loop from the engine outlet (just below the big radiator hose outlet on top R/H side of the engine) to the heater core return pipe (accessible from under the van on the back L/H of the motor) this will eliminate about 95% of your hoses and piping. You will still have the 2 hoses of death and the throttle body stuff still on-line, but both heater cores and all their piping will be disconnected. Tim

[davidgracevan]

-thanks sir Tim. but, can i also remove the hose of death? can i just plug that small tube and remove the hoses from the throtle body?

[timsrv]

The throttle body is heated by coolant to prevent icing in cold climates. So yes, you could block off/bypass this stuff too but I'm not sure what benefit there would be. Due to limited access, unless you already have a leak, why go to all the trouble? Even then, hoses last for 20+ years and it would be much easier to just replace the hoses than figuring out how to block off. If you use a section of hose to bypass, then that hose would be just as long as the combined factory hose lengths anyhow. I suppose you could just get rubber caps and block these off, but I'm not sure how that would be better than just replacing the bypass hoses when that becomes necessary. Tim

[llamavan]

Toyota allegedly shipped the vans with various heater configurations, including both, front only, and none.

I would personally avoid bypassing the heaters, especially the front one. (1) Hoses are easy to replace, really. (2) On more than one occasion, I've had to throw on the heater core to mitigate rising or just plain higher-than-normal engine temps. It's cheap insurance, whether it gets you home or just buys enough time to get safely to the side of the road ... but it only works if you have it.

My two cents.

Gwen

[timsrv]

I tend to agree with llamavan. If however I lived in a tropical place and the heater core(s) leaked I may remove these from the system. If it's just hoses that needed replacing, I would simply replace the hoses and forget about it for another 15 - 20 years. Tim

[davidgracevan]

-thank you for replying guys. actually i do agree with you both, but here's what made me decided to just remove all of the hoses, since i'm already a 3rd hand owner of the van, the previous owner already did some unnecessary modifications that really gave me hard time restoring van. examining van, i found that the heater cores are already gone and the hoses are left underneath bypassed with a tube. it is now starting to leak a bit, so i'm planning to just remove all of those since there's no heater cores for me to reattach them anymore. what do you think guys?...

[timsrv]

If there's no heater cores then there's no reason to have the hoses there (just excess baggage and more potential leak points). Rather than cap off the bypass hose nipple on the back of the head, it would be more reliable to drill a couple of holes in a metal plate and block it off that way. Of course there's still the metal return pipe (about 3' long) that attaches to the engine behind he thermostat housing. That one has the 8mm return nipple on it for the "2nd hose of death". I would probably shorten that pipe to eliminate the 8mm nipple, then you won't need as much 5/8" heater hose to bypass the heater system.

[davidgracevan]

-thank you sir Tim :)

[mahleek87]

Having some issues here today and trying to figure some stuff out.

I ordered the hose from Toyota which goes from the water pump to the T on the right side near the top right of the radiator. We installed it and it is fine. But then the other T that is next to that T has a hose that goes to the rear heater which is giving me problems. That T is rusted and since it is a rusted pipe, Im trying to figure out if there is a way to bypass it safely. I would still like to have the heat work in the front in the winter, but do not care about the heat in the back...

Please help with some ideas on how we could bypass this T Pipe because the whole pipe is rusted and its only a matter of time before something else starts leaking.

[timsrv]

If you're not using the rear heater then you don't need the tees. Just bypass with regular heater hose. the only thing you care about now is making sure there is a path to & from the front heater core. Tim

[mahleek87]

So basically send a 5/8 hose from near the water pump to the front heater core? Bypassing the T's? And not needing this hose that I bought from toyota part number 87245-87014?

[timsrv]

Probably. I haven't looked at this issue for a while so I can't give you specifics. Once you get in there and look at things it should become clear what to do. The tees are for splitting the heater hose system to share with the rear. If you don't care about the rear, then you don't need them. Just run the hose to the next joint after the tee (on the front heater core side of the system). As long as it's sealed between the engine & the front core you'll be okay (you'll need to do the same thing on the other side (other tee). Since you're bypassing the tees, the formed hoses from Toyota are probably too short. Just use bulk hose and cut to length. Tim

[Don Kihote]

May I still install thermostat after cut off front and rear heater pipe?

[mahleek87]

Tim,

Whenever you get a chance if you could document how one could bypass the rear heater lines I think it would be helpful for the whole community because everyone is bound to run into this problem sooner or later. The reason why I want to know the correct way to do this is because I'm inbetween switching mechanics soon. Alot of times mechanics have their own opinions how to do things unless you insist that "this is the only way" they might try to do it their way. And even when it fails I'm always limited on time to go back and get it redone. I think it would be a useful ad-on to this site.

[trestlehed]

Tim,

Whenever you get a chance if you could document how one could bypass the rear heater lines I think it would be helpful for the whole community because everyone is bound to run into this problem sooner or later.

I second this motion, as I've asked my mechanic to do this bypass after he has rebuilt the top half of the motor and installed the famous "Yuba City 4 row radiator".:thmbup:

[mahleek87]

I second this motion, as I've asked my mechanic to do this bypass after he has rebuilt the top half of the motor and installed the famous "Yuba City 4 row radiator".:thmbup:


The fans are waiting. If anyone can document this it would really be helpful. I want to bypass my rear heater correctly before it starts getting too cold outside.