croaker

I have a leak on the line going to the rear on my proportioning valve. Just started leaking no line changing. Looks to be leaking from threaded area. I unscrewed it and retightened it a few times still leaking. Any tricks you guys use. I know if I have to replace the block it’ll probably be a inferior piece and my troubles will multiply.

croaker

If I change the valve will I need the tool to recenter the spring loaded valve? I pretty sure it won’t come with the new one.

74_stingray

Croaker, on your 75, if you have a leak at the rear line, I would check the weep hole on the proportioning valve , it’s likely the source of the leak.

Reference the first part of this thread for more information. The proportioning valve that Willcox sells for 74-77 is a quality replacement part, or you could go to musclecarresearch.com for a rebuild kit.
Techoca’s Winter Project
Muscle Car Research

Eddy

74_stingray

You will not need the tool if you pressure bleed, if you bleed by pumping the pedal just push easy as you normally would and you will not need it.

croaker

Thanks for the help. I probably use a vacuum pump to get it started then gravity.

mrvette

Mine leaked on my '72, just remove it, useless anyway......and put in a splitter/T fitting to the front brakes, and put the rear brake line into the m/cyl directly.....mine been that way for some 20 years now.....

CA-Legal-Vette

Thanks for the link!

I’ve had mine apart before and have to admit that I didn’t even know to disassemble the piston. Until you do, how the mechanism functions isn’t obvious. I was thinking of doing the same thing that Gene did and eliminate it completely.

74_stingray

Croaker, I’m going to send the kit to you no charge. I tried to pm you back, it says your storage is full. Just send me address, I lost it.
Eddy

croaker

I tried cleaning some messages see if address came thru. Thanks

20mercury

Hi Croaker!

FWIW, I swapped out my proportioning valve on the 76 I had with one from one of the Corvette vendors, likely Corvette Central or Zip. Quality part complete and worked great, not cheap though, I want to remember over $100. If the seat is leaking, or has a burr in the cupped double crimp on the brake line, I have had some luck taking a drill bit, 1/4+/- and lightly turning in the brake line seat by hand only(not with an electric drill), to clean up the mating surface on the brake line. Obviously this is an area a light touch is a good thing and this might be a bubba fix, so you decide. Also, making the old brake line up absolutely square to the new proportioning valve is important and sometimes tricky for me. I did not use any tool to reset the valve, wife pumped the brakes while I bleed and all was good.

Hope this might help.

croaker

You still Vetting I remember you told me you sold one.

20mercury

Yep, A double S deep in C3 projects now, and happy as a clam (but no clams in Louisiana, maybe happy as a crawfish in its hole, ha!)

The 68 you saw took off to Minnesota via ebay, oh well.

Hope to see you again soon! These C3's are fun!

Street Rat

I have used these brass flare washers for pesky leaks on the brake flare connection.

I changed the front brake crossover line with a stainless steel line. I couldn't get the flare fitting at the combination valve to seal.

This especially true of the stainless steel lines with hard to seal flare ends.

20mercury

Good to know and thanks, where do you buy them?

Street Rat

Fleabay

MBrianB

I had to use these on my '72 after going through three new valves trying to get the new SS lines to stop leaking.
Get them from Graingers. Two sizes.

croaker

Well after pulling my proportioning valve I found this. Kinda like plumbing after you touch one part the rest craps out