Leaking warning brake which on Chevy disc brake conversion proportional valve.

[Gas Pig]

I just recently did a Chevy disc conversion and the new proportional valve is leaking brake fluid around the brake warning switch. Any fixes for it… new o-ring or plumber’s tap or is just failed and I need to replace it?

Anyone experience this issue?

 

[DirtDonk]

Very unusual place for it to leak.
Are you sure it’s the brake warning light switch and not the usual suspect, which is the rubber booted delay valve sticking out of the end?
The one with the pin sticking out of it.

 

[DirtDonk]

In fact, I question whether there’s even supposed to be fluid there at the switch.
A lot of us have actually removed that light switch and not had any fluid leak out of it. I don’t believe there is even an O-ring, or any kind of a seal associated with it.
It’s possible they expect the plastic threads to seal better, but I believe they don’t actually expect it to have to seal at all.

 

[TAC71]

In fact, I question whether there’s even supposed to be fluid there at the switch.
A lot of us have actually removed that light switch and not had any fluid leak out of it. I don’t believe there is even an O-ring, or any kind of a seal associated with it.
It’s possible they expect the plastic threads to seal better, but I believe they don’t actually expect it to have to seal at all.

Should not be fluid leak at switch.
Those GM style prop vslves are made in cambodia TOTAL garbage .

 

[Gas Pig]

In fact, I question whether there’s even supposed to be fluid there at the switch.
A lot of us have actually removed that light switch and not had any fluid leak out of it. I don’t believe there is even an O-ring, or any kind of a seal associated with it.
It’s possible they expect the plastic threads to seal better, but I believe they don’t actually expect it to have to seal at all.

I agree I don’t think it should not leak no matter what from there because I never had a stock H block leak like that. But both of my GM proportional style valves have O-rings the first one had the shuttle sticking issues after bleeding. This second valve keeps getting fluid on top of the valve. First I thought it was one of my lines needed tightening. But where the plastic switch is there is a small step up compared to both front and back brake lines coming from the master cylinder. It’s impossible for the fluid to go up the step up to the switch.

I could be wrong about the whole thing but the way this build and the failed parts I have had on it nothing would surprise me. I’ll double check things again tomorrow and report back.

 

[Gas Pig]

Should not be fluid leak at switch.
Those GM style prop vslves are made in cambodia TOTAL garbage .

Well it’s becoming more apparent that parts nowadays can be very suspect even if they are new.

 

[ksagis]

Check the rest of the fittings on the proportioning valve, particularly the plugs that you might not connected to and be sure they are tight and not leaking. Those sometimes leak and drip down to the other fittings and can be misleading as to root issue.

If hard to identify the culprit, another trick to identify the offenders is to tape witness paper around various fittings and then inspect the paper. The paper keeps the fluid from traveling someplace and giving a false signature of location.

 

[Gas Pig]

Check the rest of the fittings on the proportioning valve, particularly the plugs that you might not connected to and be sure they are tight and not leaking. Those sometimes leak and drip down to the other fittings and can be misleading as to root issue.

If hard to identify the culprit, another trick to identify the offenders is to tape witness paper around various fittings and then inspect the paper. The paper keeps the fluid from traveling someplace and giving a false signature of location.

Great idea… I’ll do that for sure!