82 rear brakes

[the legend]

I have a 1982 vette having problem with rear brakes. when applying brakes rear hardley work at all, I have removed master cylinder and inspected for operation and bench bled,bled all four calipers and the rear barely have fluid flowing from them. I thought it might be paportioning valve, but after reading other threads dont think so. Now believe it might be rubber brake hose in rear. Any thoughts? Thanks for any help.

 

[Rex S]

Bench bleeding will not show a master cylinder that is "blowing by" internaly as it must be under pressure. Hoses may also be going out espically if you don't know how old they are. Simple way to see how old they are is rub your hand across them, if they leave a black sooty like stuff on your hand they are to old as the rubber is breaking down and the inside is as bad as the outside.

 

[the legend]

Bench bleeding will not show a master cylinder that is "blowing by" internaly as it must be under pressure. Hoses may also be going out espically if you don't know how old they are. Simple way to see how old they are is rub your hand across them, if they leave a black sooty like stuff on your hand they are to old as the rubber is breaking down and the inside is as bad as the outside.

Yes I thought that bench bleeding wasnt telling me if it was building pressure you just confirmed my thoughts as well, I will check the hose in a while. Thanks very much.

 

[6880 Mike]

Most of the braking effort on a C3 will be the front pair. When you bled the rears, did you bleed the inner halves first?

 

[Vette79]

Most of the braking effort on a C3 will be the front pair. When you bled the rears, did you bleed the inner halves first?

Tapping on the calipers with a rubber mallet while bleeding will help release some trapped air. So both rear calipers are not working? As Mike mentions, most of the braking is done up front. Any leaks or parking brake light on?

 

[the legend]

Tapping on the calipers with a rubber mallet while bleeding will help release some trapped air. So both rear calipers are not working? As Mike mentions, most of the braking is done up front. Any leaks or parking brake light on?

Yes I bled inner half first. I realize that front should work harder but I dont believe rear work much at all. When you get out of car front wheel can hardley be touched, while rear are barely warm. Also when stopping in gravel at low speed less than 5mph front will slide, in rain high speed front will skid. At either time car will not act as if trying to stop. Any ideas Thanks

 

[6880 Mike]

Try resetting the proptioning valve. You will need a level deserted parking lot or similar. Straight line acceleration up to 25-35 mph. Stomp the brakes (panic stop). That should center the valve if the valve is sticking.

Be safe.

 

[Vettehead Mikey]

No need to have the car in motion to do the above reset. Sitting in your driveway is much safer.

 

[the legend]

No need to have the car in motion to do the above reset. Sitting in your driveway is much safer.

Thanks guys I will try stomping on them and see if that works. I've tried putting hard pressure on them but did it gradually and did not work.