Brake adj. after system rebuild on an 83 qv ??

Is your proportioning valve installed backwards?

Just a thought..


Greg

77 308 GTB

 

Maybe your rear calipers have seized/need a rebuild?

If you're getting fluid out of the rear bleeders, then the problem would seem to lie in the caliper itself...

Greg

PS--parking brake is cable operated, should have no impact on the hydraulic action of the caliper--unless you adjusted it all the way tight, so the thing was always clamped to the rotor!!

 

When you change all that stuff, it can be hard to get all of the air out and it seems like you still have some air in the system. If you have a lot of air in the system, the fluid will flow past a big air pocket. The fluid will look air free, but the air pocket with prevent the brakes from working. Did you pre-bleed the calipers & lines? This will be a big help in getting the air-out. If not, you may want to open the line at the calipers to let gravity push the air & fluid-out.
My Corvette brakes were tough to bleed especially if they had a lot of air in them so I learned a few methods.
You may want to try different bleeding methods. What method are you using? Sometimes brakes respond better to more subtle bleeding methods.
The old method of having someone pump the brake pedal then slowly push it down when you open the bleeder can work better than a vacuum system. Also, after you think all the air is out, I would recommend opening the bleeders (making sure they are lower than master cylinder) and let the fluid run out. While you have them open, tap on the top of the caliper & master cylinder with a small open end wrench--sometimes this will break a stubborn bubble free. If there is no air in the system, the fluid will run out at a pretty fast rate.
You do have to make sure there master stays full
Sorry about the rambling, but its late.

Mark

 

I specifically went after the parking brake issue on my 308 last year. In the process, I decided to rebuild the rear calipers. I found that if I went with a tight .004, the parking brake was poor at best, but the brakes were fine. A year later & about 5000 miles and I think it's time to re-check the parking brake. It does little again.

 

This is probably good advice.

It looks like you still have air in the rears. Get a helper to "pump it up and hold it". Release the pressure and repeat for both sides. I'll bet after a few cycles you'll see a bunch of bubbles and it will begin to work. It's a good idea to do the fronts as well just as a final check.

Sometimes bleeding brakes seems to defy the laws of physics.