Changing the coolant breather valve

[shlim8]

I ordered my breather valve from the OPC in Malaysia and it cost about US$49. Which was surprising as the OPC in Singapore wanted more than twice that.

Anyway, I tried keying the part no into Pelican Parts and I think the price that came back was about US$80 if I wasn't mistaken.

It's a long wait for the part though.... up to 3 weeks was what they said.

Dale, I'll keep you updated once I get the breather valve.... it's no fun listening to the hissing sound from the area of the valve every time I do a spirited run. At least the coolant loss is quite small (fingers crossed !!!).

[shlim8]

Finally got the breather valve installed this morning. The hardest part of the whole install was only the removal of the old breather valve housing. There is just no space to get a good grip of it. I used 2 allen keys (for the ikea furniture) and stuck them through the holes in the housing and yanked the housing out.

My old breather valve diaphram was in pretty good shape but the bolts were totally rusty and the O rings were slightly deformed. I found that everywhere the coolant came into contact with the plastic, the plastic looks different - you can actually see the fibres, whereas the dry parts were smooth. Does it mean I have corrosive coolant ??

Went for a 15min drive and after letting it idle for another 5 mins, the breather valve went to work and vented. Is it supposed to vent so quickly ? The housing was just somewhere between hot and warm and I could still touch it (water temp was around 85 degrees C, I have the low temp thermostat). This is a brand new breather valve that I just bought from the OPC. If it still vents so quickly, I presume I'll still get condensation on the trunk lid ??

The breather valve looks like an over-engineered item, on my E36 BMW, it's just a screw like thing on the radiator... (I know as it broke once !)

[shlim8]

Sigh, the new breather valve did not solve the problem.... or maybe I've got a new problem, don't really know as I never knew where the "old" leakage was...

I've now got bubbling from the bottom of the breather valve housing, when the car is hot and left idling for a while.

My first thought was that the 0 rings were not seated properly. I've re-installed the breather valve 3 times, checked for dirt, cracks or anything that might cause a leak. Can't see anything and the bubbling is always at the same exact spot !

The threads of the bolts holes in the coolant tank seems fine, but is it possble that the leakage is from one of the bolt holes ?? Bubbling is from the side of one of the hole locations. I'm pretty sure the O ring is seated properly. The bolts are tighten to hand tight and then about 1/8 of a turn more or less. The bolts were really loose on the original breather valve.

Any ideas ?? Other than a new coolant tank ??

[insite]

you have a crack. time for a new tank.

[Dale_K]

Anybody have a picture of the tank opening once the bleeder valve is removed? I replaced my bleeder last week and didn't see any o-rings at all. There was a circular disc with a couple rows of holes sort of near the center but I didn't lift that off. Are the o-rings under that? I doubt my bleeder valve was actually bad. The new and old looked and operated identically.

[Andrew McD]

Is it possible to remove the valve to see if it needs replacing? And if so what would I be looking for?

Thanks, A.

[schoir]

Originally Posted by Andrew McD

Is it possible to remove the valve to see if it needs replacing? And if so what would I be looking for?

Thanks, A.

Andrew:

Yes, it can be removed... See the photo I attached in the previous post for what you end up with once it's completely removed.

If you go to the trouble of removing it, you may as well replace the O-rings.

Also inspect the rubber membrane immediately under the top portion of the assembly.

There is a photo of a defective one earlier in this thread.

BE VERY SURE to heed the cautions against overtorquing the bolts.

Regards, Maurice.

[shlim8]

Originally Posted by Andrew McD

Is it possible to remove the valve to see if it needs replacing? And if so what would I be looking for?

Thanks, A.

It is possible to remove the valve, but I wouldn't mess around with the valve unless u intend to change it or the O rings. The design of where the bolts go into the coolant tank is downright scary. There are just holes on the top of the coolant tank, not raised or marked so it's easy to mis-thread them. And this is 10 yr old plastic (in my case).

There is only 2 things you can change - the entire valve (which includes the valve, housing, 2 O rings and the bolts in one set) or the 2 O rings (can be bought separately).

[shlim8]

Originally Posted by Dale_K

Anybody have a picture of the tank opening once the bleeder valve is removed? I replaced my bleeder last week and didn't see any o-rings at all. There was a circular disc with a couple rows of holes sort of near the center but I didn't lift that off. Are the o-rings under that? I doubt my bleeder valve was actually bad. The new and old looked and operated identically.

The O rings are below the breather valve housing (the one with a couple row of holes).

My new and old valve were NOT the exactly the same.... It looked the same but after installing it, I realized that the valve (centre plastic piece with the metal ring) was sticking out alittle higher. I thought I messed up somewhere so I removed it - and noticed that the rubber diaphram was alittle thicker. Hence, the valve sticks out more after installing.

It was the second install that did me in.... It was perfectly dry after the initial install. I started getting bubbling from the housing after the 2nd install. Sigh... should have left it. I think my expansion tank just went south.

[schoir]

Originally Posted by Dale_K

Anybody have a picture of the tank opening once the bleeder valve is removed? I replaced my bleeder last week and didn't see any o-rings at all. There was a circular disc with a couple rows of holes sort of near the center but I didn't lift that off. Are the o-rings under that? I doubt my bleeder valve was actually bad. The new and old looked and operated identically.

Dale:

Top of coolant tank with bleeder valve assembly removed:



Regards, Maurice.

[insite]

slim -

in maurice's photo above, from where is your new leak bubbling?