So I got my truck a couple of months ago. The PO did a rear brake job on it before I got it. He said the brakes would probably need adjusted. The problem was that the pedal goes almost all the way to the floor before they grab and then not hard. So I had a brake guy check them. He said the problem was that my front brakes were gone. He adjusted the rear, replaced the front rotors and pads, and re-bled everything down. Now the pedal goes half way down before grabbing and if I push to the floor they will grab hard. He said that I may have a small vacuum leak in my booster. No lights come on for brakes or anything. I am not a brake guy and I've spent about $300 in parts and labor so far, but I need this thing to stop on command. About the only thing left is the master cylinder and/or brake booster. Any advice/suggestions/opinions? I need to start pulling my boat, shrimp season starts next week.

 

Bad master cylinder usually bleed off. Like if your sitting at a red light he pedal will slowly go down to the floor. Bad booster usually mean the pedal requires alot of physical effort to work. A brake booster is like power stearing. It allows u to use little effort to make it work. Your brake pedal should be about even with your gas pedal when fully depressed. If u have rear drums they are usually self adjusting. When you go backwards and hit the brakes hard they self adjust. It still seems like u have air in the system. Or maby a sticky caliper. Meaning the piston isn't working steady. When you come back from a drive put your hand on your rims near the center. By the lugs. DO NOT touch the rotor or caliper. They all should be fairly warm. When one isn't working the same as others it will feel alot hotter or colder. That should help u narrow down some possibilities

 

what year truck. rear drums or rotors.

to test the booster. shut the engine off. depress the brake pedal multiple times to deplete the vacuum reserve. when its depleted completely, depress and hold the pedal down. start the engine, the pedal should drop when the truck is started. when vacuum is full and holding...you should have enough vacuum reserve for 2brake applications after the engine is shut off.

if you pump the pedal does it firm up....if yes, air is in the system.

a deep pedal is a symptom of improperly adjusted rear drum brakes. if the initial adjustment is not tight enough, it would take a long time for it to self adjust to the proper position. if the e brake won't hold; it is another sign that the drum service brakes are not adjusted tight enough.

 

I once had a shop do a complete front and rear brake job on my 99 2wd. Same thing pedal went most of way down before grabbing. I just kept taking it back to them and said it was unacceptable. The third time back they got it right, the rear drums were not adjusted properly. You should feel it grab within an inch. The self adjusters often need some manual help.