Hi,
Was changing the O2 sensor and saw this. Notice the black rubber piece in the middle of the combo valve, their is a drip of brake fluid. I wiped it off and drove the car about 10 miles. Went home and that same drip was their. Not having a braking problems with the car and Master cylinder is full. Does this warrant replacing the combo valve? Looks like a nut around it, can it be tightened? Any advice would be great.

Thanks alot.

Dean

 

Anyone? I have called around and nobody has a replacement except the dealer at $110! I need to know if I have to pay to replace or if this can be fixed at all? Rebuilit?

Please any advice would be greatly appreciated...

Thanks

 

Better safe than sorry. You can probably find a good one at a local junkyard fairly cheap. Should be an easy swap. Be sure to bleed them afterwords.

 

I'd replace it. gmpartsdirect.com will have a better price. Probably about 1/2 of what the dealer quoted you, IIRC.

 

Hi,
Well I went to a junk yard and found another combo valve (I had not heard back from GMpartsdirect so figured they didn't have it) that looks just like what I had. Replaced it and everything is working but after I was all done, I recieved the email from GM parts direct and they gave two different models. One for 4 wheel disc and one for front disc/rear drum. I have the front disc/rear drum. The car I took the valve off of had no engine or rear so I have no idea what combo that was.

How do I know if I have the right one? Would I have stopping issues if I was using the 4 wheel disc valve?

Thanks for any thoughts........

 

In a disc/drum combo valve there is a hold-off valve in the front of the prop valve that keeps the front brakes from being applied till the rear pressure has overcome the return springs in the drums. It is under a little rubber cover (that sometimes gets lost). If you take that cover off there will be a SMALL nub that sticks out. It is used to defeat the hold-off valve to make bleeding the brakes easier.

You can also change out just the proportioning part of the valve. It is the hex shaped part in the rear of the valve you described above. It just unscrews and the new one (or j/y one) will just screw in it's place.