Water Bypass Hose

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Marc311

Marc311

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I'm in the process of replacing all my coolant hoses. As I am knee deep in PHH madness at the moment, I noticed another coolant hose running from the block (near the PHH) up to the throttle body. It is the Water Bypass Hose and CDan had sent me one along with all the other hoses.

It looks like it will be even tougher than the PHH! For all the complaining about the PHH, I don't see anything about the WBH. Are people just not replacing this??

Mine looks like it is in good shape (130K), but as long as I am replacing everything I might as well do it. But can it be done without taking the intake off? The PHH looks surprisingly good from the inside and out. The WBH looks even better.

Any suggestions or advice would be appreciated. If it can only be done by removing the intake, that hose is going to have to wait. But if anybody knows a trick to get it off/on - please let me know.
 
I did it without removing the intake. I did take the throttle body off, but I was able to swap hoses without using any fancy long handled pliers (which might have made it easier). It's doable, but it will most likely involve some awkward stretching and a few curses/grunts. Mine looked ok on the outside but the inside of the top end was starting to degrade at 170k miles.
 
I'm in the process of doing the same. I have one addditional problem though, There are coolant hardlines that run above the transmission to i believe the rear heat blower? The PO has bypassed the hardlines. I'm not sure why? Although they look very rusty.
 
Thanks. It looks like it might help if I took off the cables to the throttle body. But maybe I'll just pull the whole thing.

I also noticed a short bypass hose in the set that Dan sent. I guess I need to find where that one goes as well. I have a feeling it is equally buried.
 
Marc311 said:
......... I noticed another coolant hose running from the block (near the PHH) up to the throttle body. It is the Water Bypass Hose and CDan had sent me one along with all the other hoses.

It looks like it will be even tougher than the PHH! For all the complaining about the PHH, I don't see anything about the WBH. Are people just not replacing this??..........
Click to expand...

Pics please! WTF are you talking about? Is this a rubber 5/8" hose? My '94 doesn't have this hose, I hope!
 
Marc311 said:
Thanks. It looks like it might help if I took off the cables to the throttle body. But maybe I'll just pull the whole thing.

I also noticed a short bypass hose in the set that Dan sent. I guess I need to find where that one goes as well. I have a feeling it is equally buried.
Click to expand...

Just pull the whole TB with the cables in place. It's two hose clamps to remove the big rubber intake hose, then undo the two electrical connectors on the TPS and IAC valve (front of the TB). The TB is on with four bolts (12mm head IIRC, and possibly two longer than the other two?). There is a metal gasket between the TB and intake plenum that you can reuse. Then you'll see the two coolant hoses that you can undo from the TB, and thats it! Lay it on the exhaust manifold. TThe short hose is where the coolant exits the TB and runs into a metal pipe.

Also a good time to get some TB cleaner and go to town on the EGR pipe in the plenum.

:cheers:
 
80t0ylc said:
Pics please! WTF are you talking about? Is this a rubber 5/8" hose? My '94 doesn't have this hose, I hope!
Click to expand...

It does ;) I'd say it's about a 3/8" (10mm) hose. There are some pics of it in threads about valve cover gasket and throttle body removal, but Marc could probably get better ones.

Here's a pic from mine. You can see the top end of the hose dribbling a bit of coolant on the left.

IMG_0006.JPG
 
Yep - that's it at about 7 o'clock in the photo above.

I think you're right about just pulling the whole TB (Mine could probably use a cleaning anyway). Are there 2 or 4 bolts holding the TB? I can only see the top two. Still searching in my FSM. EDIT: 4 bolts - see it now on pg EG 161 which also shows the second little water bypass hose I mentioned above. Off she comes.
 
Marc311 said:
Yep - that's it at about 7 o'clock in the photo above.

I think you're right about just pulling the whole TB (Mine could probably use a cleaning anyway). Are there 2 or 4 bolts holding the TB? I can only see the top two. Still searching in my FSM.
Click to expand...

OK, thanks, guys, for showing what you're talking about. I'd suggest while you're in there, to replace all the vaccuum hoses that you can reach, too. I did a search and seems like best opportunity to replace those bypass hoses was during a HG replacement or vaccuum hose replacement. Seems like it could work the other way, too.
 
80t0ylc said:
OK, thanks, guys, for showing what you're talking about. I'd suggest while you're in there, to replace all the vaccuum hoses that you can reach, too. I did a search and seems like best opportunity to replace those bypass hoses was during a HG replacement or vaccuum hose replacement. Seems like it could work the other way, too.
Click to expand...

Agreed! I didn't, and I ended up doing it later when I replaced my VSV for EGR. See the larger vacuum hose coming off the intake plenum at 4 o'clock and running down to the plastic T under the plenum? If I understand it correctly, it is the main source of vacuum for the EGR and EVAP circuits. Mine was all cracked and dry and definitely leaking, which may have contributed to my P0401.

IMG_3508.JPG
 
We just did this same project. Starting with the PHH, SIL Brian (Budvar) went to Cruiser Dan and bought the 20(!) radiator, heater and bypass hoses for his FJZ80. We slowly but surely worked through all of them including the P(F)HH until we reached this last bypass hose. After 12 hours replacing all of these hoses, we got to this last one. At this point, we were both thinking, "You've got to be kidding!" One end is ABOVE the PHH and the other end needs the throttle body removed to reach. After looking at it for 15 minutes, we decided that this was a low pressure line, was in otherwise good condition, and was right up there with the PHH as being freaking impossible to replace. Bottom line is that we replaced 19 of the 20 hoses on his FJZ80. Were we wrong?
 
I know this is an old post, but my water bypass hose just started leaking out on the trail. Fortunately, it was a slow leak and I brought extra coolant. I suggest replacing the hose while your in there.
 
Those hoses are a PITA. Toyoda engineers were so thorough, they designed the engine to fit Japanese hands.
 
Replaced mine yesterday, holy s*** was that a pain in the ass. I think doing the PHH was a good learning curve for the WBH. I bypassed the Throttle body.
 
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