Don't know why my brakes don't work.

[Kapdin]

These pic's should say it all. One question tho, the drums are very grooved, can they be ground down like disk's?

 

[bucket]

Wow, original GM spiral shocks!

 

[Kapdin]

lol they are pretty gross. That is also the leafspring pack i replaced, which took all of our 1" drive breaker bar and 2 foot cheater to get off....

 

[HotRodPC]

You can have drums turned and trued if they are still within tolerable specs. If not, they need replaced, and it's important that you don't let them get out of spec. IF you do, you can push your wheel cylinder pistons out to far, lose all your fluid and your brakes in a matter of seconds.

 

[Kapdin]

So after replacing everything in the rear brakes and bled the rear i still don't have pressure on the pedal at all, i havn't opened the front yet tho. Also my brake light is stuck on now? never touched the parking brake. Thinks its my master cylinder? cus i have fluid coming out at the rear just not under pressure.

 

[crazy4offroad]

Air is trapped in the proportion valve which is located on the far front crossmember under the radiator. It takes some serious pressure and full stroke of the brake pedal to dislodge it. You may want to start catching your brake fluid as you bleed them so you dont have a lot of waste.

 

[Kapdin]

....there might have been so force, when i flushed my tranny i didn't want to slam it in to rev and drive and back again while the wheels where spinning (truck up on jack stands). They still didn't work.

 

[crazy4offroad]

For your brake light to be on indicates your proportion valve has air in it.

 

[Kapdin]

Makes sence. And to fix this i can just clean and bleed my front?

 

[crazy4offroad]

Yes the front moves a larger volume of fluid when bleeding. Sometimes it can be a real bitch to get the air out of the proportion valve. Had a similar issue, never could get the brake light to go off so I unplugged it. I think HRPC told me the switch can come out too far. I have good pedal so I dont really care about the brake light.

 

[HotRodPC]

Yes, in MOST cases a good brake bleed will dislodge the prop valve piston because it makes it swing from one side to the other of the valve then it resets itself.

 

[bucket]

For your brake light to be on indicates your proportion valve has air in it.

Maybe not air in the valve, because a large pressure difference between the front and rear circuits will trip the switch. Even rear shoes that are way out of adjustment can make the light come on when you slam on the brakes.

Did the fluid level ever get low enough that the master cylinder could have sucked in some air?

 

[HotRodPC]

Maybe not air in the valve, because a large pressure difference between the front and rear circuits will trip the switch. Even rear shoes that are way out of adjustment can make the light come on when you slam on the brakes.

Did the fluid level ever get low enough that the master cylinder could have sucked in some air?

You're right, but nonetheless, a good MC topping off, bleeding, and retopping off the MC will reset the prop valve and light should go off no matter where the air is, and it may not even be air. It may have just be a hung up prop valve and that's all it takes.

 

[89Suburban]

You're right, but nonetheless, a good MC topping off, bleeding, and retopping off the MC will reset the prop valve and light should go off no matter where the air is, and it may not even be air. It may have just be a hung up prop valve and that's all it takes.

So there is no special procedure to reset that valve?

 

[Kapdin]

No the MC was full from the get go and i just watched it as i bled the rear and added very little. The light was not on till you reminded me i was kinda wrenchin on the pedal that day. I can watch the fluid jump in the mc with the cover off like the mc is pumping but yea no real pressure to speek of.