Proportioning valve going out...

Hi all, just a quick and (hopefully) simple question for you all. I drive a 1983 camaro with the stock brake setup, and apparently my proportioning valve is shot. The problem came up when we noticed that the car's rear wheels would still turn even when the brake was pressed to the floor. We discovered this lovely little problem after noticing an unusually high rate of wear on the front brake pads. We tried flushing and bleeding the brake system, replaced the master cylinder and all the rubber lines in the back, and even replacing the shoes on the drums. We have come to the conclusion that the proportioning valve is all gunked up and needs to be replaced. Unfortunately, GM apparently doesn't make this part anymore. Now, I haven't lost all hope yet. My friend recently totaled his 92 RS and is selling parts off it to recoup some of his losses. He has what appears to be the same valve.

So what I need to know is 1. can I swap out my valve for his? and 2. if not, does anyone know where I can find a replacement? and finally 3. is this valve a part that breaks down often? I've been wanting to convert to rear disc brakes for a while now, this may be my excuse. Of course, if I can just shell out $25 for my friends valve to fix the problem, I would rather do that than go through the hassle and expense of installing rear disc brakes.

Thanks in advance for your help guys, sorry this wound up being such a long post!

If the valve appears to be the same I don't see why it would not work. If you need the car to drive I would fix it for the 25 bucks. If not, like you said just get the rear disc now and save the time of trying to fix the valve...
Just my:2cents:

Autozone wouldnt have one? even one made by a 3rd party company?

they cant just dissapear with how popular the camaro is, you might not get a GM one but theres always aftermarket.

incase the V6 one doesnt work.

Alright I guess I will pull both proportioning valves out of both cars and compare them. They are both of off 305 V8 cars. I haven't been able to find anything aftermarket though.

i'd say get his then. didnt know it was a 305, most RS are v6 right?

I know jegs has some Ive bought a few off there. Im sure summit has more, jegs was kinda limited.

Alot of RS are 305's

You mention all the parts that you replaced already but, my question to you would be....... Are you sure that the wheel cylinders are doing theire job?
If those have blown the internal seals they will only half work because the fluid will bypass and wont push the piston out properly
I would check those out first

When you pump up the brakes and hold the pedal like your bleeding it, when you crack open the bleeder if fluid doesnt seem to flow from the bleeder very much, you could have a restriction of some sort. After you open the bleeder with the brakes pumped up a few times, you shoud have a nice puddle of brake fluid to clean up. Also when you open the bleeder, the pedal should go down to the floor quick, no longer than about a second. If it takes longer than that for the pedal to go down as far as it will, you have a restriction.

Some camaros have standard connections at the proportion valve, some have metric connections. Put a wrench on one of the lines coming from the valve. See if it takes a standard or metric tool to remove the lines. If your car has the brake system that uses a standard wrench to remove a line, and the later model camaro has a brake system that requires a metric wrench to remove the lines, the valve will not fit, nor any of the other brake parts. An 83 usually has standard line fittings, a 92 probably has metric.

moving to problem diagnosing.

if both cars have the same brake setup it should work. Front disc/rear drum and what not

Alright I was doing some searching on Jegs and ran across this adjustable proportioning valve... I know it's not a direct factory replacement but what do you guys think? Thanks.

your stock proportioning valve will rarely go bad and only "proportions" the fluid pressure under hard braking. Under hard brakeing this valve will restrict the amount of fluid going to the rear to allow more braking in the front. If this valve does go bad normally you would experience the rear tires skidding under hard braking. The adjustable unit you found in Jegs is normally used in conjunction with the stock proportioning valve to further regulate the pressure and is placed in the rear brake line just after the stock valve.

Drum brakes get kinda sticky at times and need to be "massaged" you can manually adjust the shoe clearance to push them out closer to the drum. Also the drum may be worn out or your brake cylinders are leaking and thereby lack the hydraulic push to effectively apply the brakes.

Cool, thanks very much for the input. I'll take a look at the rear drums again.