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I noticed some brake fluid on my garage floor so upon investigating I find out that it is coming from the proportioning valve. You can see from the photo that it is coming from that round place whatever it is called. How can you repair that or do I need a new proportioning valve? . You can see a drop that has run down to where the line goes in to the valve.
Last edited by Monterey C6; Mar 15, 2020 at 12:04 AM.
When you go to buy a new one. Study-study-study. Not just price, but make sure you get the correct yr. The brake light warning switch on the top of the unit, changed style over the yrs. If you get the wrong one, some modified wiring will be in order.
What the vendors are charging for those new Prop V, it must be solid gold with some holes drilled in it.
Update:
I did some research on Google: Drawings of C3 Proportioning Valve. Some good photos there.
It seems the back portion of that Prop valve is removable. Maybe for changing out the piston seals, cleaning? IDK
I guess you do not have much to loose if you remove the rear brake-line, put a socket on that valve and give it a twist. If the back part come off, give it a good cleaning around the threads. May have to work fast, dripping brake fluid.
Apply a dab of thread sealer, install, reattach brake-line, bleed the rears. Either the leak will stop or a new valve is in order. Might save you $90.
Last edited by HeadsU.P.; Mar 15, 2020 at 11:58 AM.
Thank you everyone. As HeadsU.P points out that back portion does come off. I think what I may do is take that off and attempt a repair just to see if it is possible. However for my final fix I'm going to replace it for peace of mind.
Another question I have is why would there be a weep hole on this? I was reading an older thread where someone's was leaking there. They replace the whole proportioning valve but they did show that rear part removed. A cleaning May fix that but I'm just curious why there would be a provision for a weep hole to begin with?
I don't know. I question if it truly is a weep hole. Might be something that was used on the assembly line. IDK Maybe a tool was inserted to bleed off some air?
If you want to see the inside of that, click on my profile, photo albums, Prop Valve, has a drawing.
Last edited by HeadsU.P.; Mar 20, 2020 at 09:00 PM.
proportioning valves are considered non-serviceable items. it's also a safety device. don't mess with it. just replace it.
I can see mine but it looks like a real PITA to get to to change if necessary. My brake warning light is staying on and if bleeding brakes doesnt fix the problem a change may be in my future. does it have to be done from underneath i dont see anyway from the top with brake booster and master cylinder in the way
Mine was just like yours - I did replace it but seeing how rusty the brake lines were - I replaced every single one in the car. Something to think about. Brakes is something you just do not want to cheap-out on. Pretty much all the Corvette vendors carry all the brake lines.
Proportioning valve leak. Help
