bypass nipple leaking at the thermostat housing... is that a thing? (1 Viewer)

[AaKnight]

Been chasing a small coolant leak, its puddling on top of the thermostat, around and behind the bypass hose connection and we are loosing about 1/2 gal in a month. I originally changed the 3 o-rings for the small pipe that goes to the head. when that didn't work, i changed the bypass hose and new oem clamps. it seemed to get slightly worse, so I got a standard clamp and flipped the hose around. The leak did not move with the hose end. I took the hose off and inspected the nipple, theres no corrosion or damage.

So, im thinking I have a leaking nipple coming off the thermostat housing. Is this a thing? ive not heard of it before.

I assume the fix would be to replace the housing but I dont see a p/n for it (or im not finding the correct diagram).... i found a used one on ebay, but it looks rougher than mine.

anybody else had this problem?

 

[Malleus]

Did you use Toyota hoses and clamps?

 

[BILT4ME]

Been chasing a small coolant leak, its puddling on top of the thermostat, around and behind the bypass hose connection and we are loosing about 1/2 gal in a month. I originally changed the 3 o-rings for the small pipe that goes to the head. when that didn't work, i changed the bypass hose and new oem clamps. it seemed to get slightly worse, so I got a standard clamp and flipped the hose around. The leak did not move with the hose end. I took the hose off and inspected the nipple, theres no corrosion or damage.

So, im thinking I have a leaking nipple coming off the thermostat housing. Is this a thing? ive not heard of it before.

I assume the fix would be to replace the housing but I dont see a p/n for it (or im not finding the correct diagram).... i found a used one on ebay, but it looks rougher than mine.

anybody else had this problem?

When you installed the new O-rings, did you clean the groove they sit in with Scotch-Brite (or equal) pads?
Did you clean the bore of the thermostat housing the small pipe and two o-rings sit into as well?
Did you lubricate the O-rings with antifreeze, KY or Vaseline before installation in order for them to slide in gracefully? Otherwise, they may bind during assembly and tightening and tend to leak.

If you did all those things, you may see some leaking initially until you run the engine up to full temp and hold it there a few times. If it continues to leak, you'll need to replace the O-rings, the short tube, and the L-Shaped pipe.

 

[AaKnight]

Did you use Toyota hoses and clamps?

yes! Got them from partsouq

 

[AaKnight]

When you installed the new O-rings, did you clean the groove they sit in with Scotch-Brite (or equal) pads?
Did you clean the bore of the thermostat housing the small pipe and two o-rings sit into as well?
Did you lubricate the O-rings with antifreeze, KY or Vaseline before installation in order for them to slide in gracefully? Otherwise, they may bind during assembly and tightening and tend to leak.

If you did all those things, you may see some leaking initially until you run the engine up to full temp and hold it there a few times. If it continues to leak, you'll need to replace the O-rings, the short tube, and the L-Shaped pipe.

Its been a year since i did the HG, so not sure what i used to lube the orings, i may have used LL Red or spit,lol... I do remember cleaning all those parts up well tho but not anything too abrasive. pretty sure the leak is coming from the nipple because I wedged a folded piece of paper towel in that recess area above the thermostat and left it overnight. It was only wet around the bypass outlet nipple.

so being theres 3 things there, a nipple, a hose, and a clamp.... and ive replaced the hose and clamp already... so kinda means i need a new nipple.... it must be damaged somehow i cant see, or ??? .... thing is I cant seem to find the part# for the nipple or thermostat housing.

Draining and refilling the coolant sure gets old after a bit, lol.

 

[Malleus]

Its been a year since i did the HG, so not sure what i used to lube the orings, i may have used LL Red or spit,lol... I do remember cleaning all those parts up well tho but not anything too abrasive. pretty sure the leak is coming from the nipple because I wedged a folded piece of paper towel in that recess area above the thermostat and left it overnight. It was only wet around the bypass outlet nipple.

so being theres 3 things there, a nipple, a hose, and a clamp.... and ive replaced the hose and clamp already... so kinda means i need a new nipple.... it must be damaged somehow i cant see, or ??? .... thing is I cant seem to find the part# for the nipple or thermostat housing.

Draining and refilling the coolant sure gets old after a bit, lol.

Yeah, just get a new one and toss the old one. If they haven't stopped, McGeorge is running an online parts sale.

 

[AaKnight]

Yeah, just get a new one and toss the old one. If they haven't stopped, McGeorge is running an online parts sale.

any ide what diagram that part is on? i cant find it anywhere except the FSM

 

[flintknapper]

93-97 Toyota Land Cruiser FZJ80 1FZ-FE Thermostat Housing Coolant Pipe OEM | eBay

Find many great new & used options and get the best deals for 93-97 Toyota Land Cruiser FZJ80 1FZ-FE Thermostat Housing Coolant Pipe OEM at the best online prices at eBay! Free shipping for many products!

www.ebay.com

 

[flintknapper]

any idea what diagram that part is on? i cant find it anywhere except the FSM

It would be found in the Timing Cover diagram IIRC.

 

[AaKnight]

It would be found in the Timing Cover diagram IIRC.

well, you are sort-of correct. I have already been there... you can find its picture DRAWN on the timing diag, but not any part number. Only part number there is for the gasket

 

[BILT4ME]

Here is everything you need.

Search is your friend.

I searched "bypass pipe"

fjz80 Coolant leak around bypass pipe

Hello everyone, Looking for some advice. I redid my cooling system and I've been chasing a intermittent leak near the bypass pipe. I replace the bypass #1 the first time, but didnt use any rubber grease so the theory was that the o-ring because dislodged. I took it apart, lubed, put it back...

forum.ih8mud.com

 

[AaKnight]

Here is everything you need.

Search is your friend.

I searched "bypass pipe"

fjz80 Coolant leak around bypass pipe

Hello everyone, Looking for some advice. I redid my cooling system and I've been chasing a intermittent leak near the bypass pipe. I replace the bypass #1 the first time, but didnt use any rubber grease so the theory was that the o-ring because dislodged. I took it apart, lubed, put it back...

forum.ih8mud.com

Hi, thanks! I did come across that thread in my prior searches..... but its discussing a different part, the casing behind the thermostat...not the part with the nipple... but from the last image on that thread, it appears as if that housing might be sold as part of the timing cover..... which seems strange. a small crack causing this isnt implausible tho. thanks for the link but sheesh! ... an entire timing cover????? come on Toyota.

 

[BILT4ME]

Hi, thanks! I did come across that thread in my prior searches..... but its discussing a different part, the casing behind the thermostat...not the part with the nipple... but from the last image on that thread, it appears as if that housing might be sold as part of the timing cover..... which seems strange. a small crack causing this isnt implausible tho. thanks for the link but sheesh! ... an entire timing cover????? come on Toyota.

OK, I misunderstood. You are looking for the hose nipple on the front side of the thermostat housing.

@flintknapper posted an eBay pic of one with a price and everything.

If all you want is NEW, then call a dealership or search partsouq.

Otherwise, @slow95z or @arcteryx may be able to provide a good used part.

 

[AaKnight]

OK, I misunderstood. You are looking for the hose nipple on the front side of the thermostat housing.

@flintknapper posted an eBay pic of one with a price and everything.

If all you want is NEW, then call a dealership or search partsouq.

Otherwise, @slow95z or @arcteryx may be able to provide a good used part.

I think your link had my answer, even though it was not the exact problem.... i just always ask you guys when i come across strange things, because info here is 1000% better than anyone at the dealership here in Tulsa. I do see the part i need (FSM calls it a 'thermostat guide') clearly being sold pre-mounted onto the new timing covers being sold. I guess they didnt expect any to ever fail. I wonder if my problem is similar to the other post, i might have a hairline crack in that housing piece causing my trouble, and mimicking the hose clamp leak.