My 71 Cutlass has no brakes at all. The system has a new master cylinder, new rubber hoses but I have no fluid to rear wheel cylinders, I was able to bleed the front wheel cylinders with no air and good fluid flow. The brake light on the dash light is lit so do I have to replace the distribution block? I have read about recentering the piston, how is this done? Any tips on removing the 50 year old lines from the block? The car has power assist drums all the way around. Any and all help will be appreciated.

 

The brake distribution block has an internal piston that serves to activate the BRAKE light if there is a pressure differential between the front and back halves of the system. You likely moved the piston all the way to one side when you tried to bleed the brakes, and if there is any crud in the block the piston gets stuck. Sometimes you can pop it loose by opening a bleeder on the other side (the front brakes in this case) and pushing on the brake pedal until the BRAKE light goes out. If it does. now gently bleed the brakes normally. If the light doesn't go out, you have to recenter the piston. You might be able to do this by removing the line to the rear brakes and pushing in with a wooden or plastic rod of the right diameter to fit through the hole in the fitting. If that doesn't work, you can get rebuild kits for these distribution blocks. Note that this vendor has different rebuild kits for the brass and iron distribution blocks.

 

Thanks for the information, the light was on prior to me doing any work. I replaced the master cylinder and rear hose because there was no fluid going to the rear wheel cylinders. I thought the front brakes would offer some braking but there is none. I will try your suggestions and thanks again.

 

Until you bleed all the air out of the back brakes, you won't get a lot of force in the fronts. Be sure the rear bleeder screws aren't plugged with rust. Be sure the rear wheel cylinders aren't plugged with rust in the bleeder screw hole (been there, done that...). Disconnect one of the lines to the rear wheel cylinders and see if you get fluid there. If not, keep working up to the M/C until you find where the blockage is.

 

Like Joe has said ^^^^

As a note of confidence for you, I rebuilt the brake distribution block (kit from Muscle Car Research), master cylinder, front calipers, rear wheel cylinders, installed new shoes, and replaced the entire brake line set--and I have brakes, great brakes!

If I can do it, you can too. The worst part is getting things together in order to get started. Rebuild major brake components--don't replace. Good luck

 

Question, if the distribution block internal piston is stuck (no longer centered) will that impede the flow of fluid and affect the pedal? In other words, if the distribution block failed (piston stuck) but the rest of the braking system is in good working order, would you have brakes?

 

You will have at least half the brakes. The side that the piston is offset towards may be somewhat restricted.