Brake help please

[GMCjunkie]

I have made up my mind to get my truck back on the road. One of the major issues im having right now, it my brakes. I have a 71 Burb 4x4. When I go to stop, the brakes feel hard, and my truck does not want to stop. I was told to leave it in park, start it up with my foot on the brake, if it goes down, its NOT my booster, well, it goes down. My pedal does NOT go to the floor, it goes about half way. It just wont stop. I have already checked the fluid in the master cylinder too. What next?

Thank you!!!

[VetteVet]

Have you adjusted your pedal free play to about 1/2 inch of travel before it pushes on the brake rod? What happens is that the rod can not return far enough to open the rear port in the master cylinder and pic up more fluid to shove down the lines to the calipers. It will feel hard because the piston will travel it's full stroke and bottom yet it won't have enough fluid to expand the brake pads.

[SS Tim]

Was anything changed or did it just start doing this?

[GMCjunkie]

Vette, can you explain how to do this? I am not super truck knowledge girl, lol. Tim, nothing has been changed, it has been sitting more than not for the past couple years though. If the fix for it is anything too entailed, I will have to take it to my truck fix it guy, lol.

[mgchevyparts]

You lose the hydraulic action of the brake fluid when you let them sit for years (air & moisture). You will need to bleed all the brakes and check for leaks. I wouldn't be surprised to find your master will need replacing. I would plan on replacing the pads and shoes and bleed entire system. AND the shoes may be frozen (rust) Generally go thru the entire brake system.

[GMCjunkie]

Oh LAWD.....I will prolly just take it to my guy next week. I wish I had never let it sit that long, but then the first almost 3 years, it was sitting in the paint shop in pieces. It seemed that it all started going downhill from there.

[SS Tim]

Remember the only thing that benefits from sitting is the odometer reading.
From what you described it sounds to me as well the master cylinder is kaput.

[VetteVet]

Checking brake pedal is a feel thing by lightly pressing on the pedal with your hand with the engine off and no vacuum for the booster. You should be able to move the pedal just a little and then you'll feel a light pressure when the pedal rod contacts the master cylinder booster rod. If you don't feel it or can't tell then you might need to shorten the rod at the brake pedal. I don't have a picture of the rod but you should be able to figure it out. If you've done assembly on this system this may be your problem.

I would also loosen the two fittings on the master cylinder lines and press on the brakes and see if you get fluid out of the master. Brake fluid is death on paint so cover the lines so they don't get fluid on your fenders or firewall.

If you get fluid here then go to the right rear wheel cylinder and open the bleeder while a helper pumps the brake pedal. If you get fluid then go to the left cylinder and repeat the process. If you get fluid there then move to the right front caliper and then to the left.

What you are doing is checking for fluid flow to the brakes and whether the master cylinder is pushing fluid. When you establish fluid flow then you can start the bleeding process.
Once all the air is out of the system the brakes should work.

I would say that it is unlikely that all four brakes would be frozen although it is possible.