Anyone ever have the coolant expansion tank leak? I pressure tested it and can hear it leaking from the tank but can't get any bubbles. I think it's the top of the tank where the seam is.

 

I can't hear anything but my ears are ringing from lack of sleep...

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Leak is most likely that connection in the lower right to the reservoir/expansion tank.

 

I responded to your other thread but yes my sound is also coming from above the expansion tank. I don't think mine is that connection, but the seam probably split at the top. I thought it could of been the adapter but it is holding pressure its just the hole in the tank is pretty big and up high so probably explains why I have no pressure but won't lose alot of coolant.

 

If you leave the pressure there and let it sit, does it (eventually) go down to 0? If so then probably different location than mine. (Mine seems to stop around 5 PSI). Interesting yours stops leaking at a certain point. I haven't let it go down too far I just keep adding every once in a while. I don't think mine would stop that bleed valve flows coolant once pressure goes up and the plunger rises. Wonder if I can just try the hose first and see if I don't need to hassle removing and replacing the reservoir....

 

Mine won't hold only pressure at all. I pump it up to 15 and it drops to 0 within a minute. The tank isnt super hard to get to. 2 hoses 1 electrical connector and a screw holding it in. Then you slide it out.

 

I’m afraid it sounds like your adapter is leaking, and/or the pump. I have two sets and the adapters are slightly different, my first set the Porsche/VW/Audi adapter leaks. To prove it I ordered a different set and tried it.


The one on the left leaks like you describe. The one on the right does not leak. I verified the pump doesn’t leak by trying a different adapter on a different brand car.

 

I hope the picture helps you determine if your adapter is leaking, probably a sign if you are getting coolant onto the threads as you see dried up silicate on the left…..

 

My cap isn't leaking i sprayed soap around it and nothings leaking from the cap. I tried a my mityvac pump on it and same results. Hissing right by the tank.

 

I have the hose on order gonna arrive at the dealer tomorrow morning. Will try to replace it and let you know if that stops the leak. It's hard to see it during daylight but shine a light in there in the dark maybe yours is the same. I've left the covers off since I first pulled them off so I don't need that step... Looks impossible to get the tank out from the top, I'm guessing pull the wheel then wheel well liner?

 

Argh. Got to pull the under panel, front left wheel, rear wheel well liner, and drain coolant before disconnecting and removing the expansion tank. Then after replacing, refill the coolant. I'm crossing my fingers regarding the hose solving the problem....

 

I surveyed what it is and there's no way I'm going to be replacing the hose from the top. Got to disassemble from the bottom. Did a couple of pressure tests I would say there's some teeny tiny leak.

t=0

1 hour later

 

Its easy to get in there once the wheel liner is off

 

Thank you. I've loosened the lug bolts turned off the suspension and placed my jack in place to lift the corner. Then I got stuck (again) trying to disconnect the hose from the bleeder valve. I remember getting stuck when I replaced the bleeder valve somewhat recently. I can't get the hose off the valve! I noticed they made a slight design change with the new hose to ease squeezing the blue-green release buttons. May try again when it's cooler or continue trying tomorrow morning...

 

Finally disconnected the top by loosening the bleeder valve bolt and raising the valve up. Then I was able to get a better grip on the two buttons and pulled it loose. Lifted the corner got the liner out then inspected. No apparent leaks replaced the hose put everything back together drove around still 201° F. Next time you open the expansion tank cap take a look at the little drain hole. (Still nervous your adapter may not be sealing well.) For mine I'm still concerned about leaking from the cap, there was a lot of coolant pooled on the wheel liner...

 

I confirmed mine is leaking past the cap this morning. I had wiped dry the overflow area under the cap and there is a pooling of coolant this morning. Maybe the viteon o-ring is not sealing well or it's blowing past the relief valve built into the cap. I have 3 different caps on order from Amazon Stant, Gates, and some strange name I'm not familiar with. (Got free shipping no Amazon Prime for me so needed to total over $25).