ok also i forgot to tell you guys on my truck iafter changing the cabs i drove it home and on my way home i pushed the brakes to stop and they got stuck down to the floor and i actualy had to yank back up on the pedal to get it back up. I disconected the bolt where the pedal hooks to the master cylinder when i changed the cabs. (its same mastercylinder ont he truck so i know the masstercylinder works great). Do you think i might have over tightened the bolt that hooks the pedal to the master cylinder? Please let me know what you guys think.
thanks,
Jimmy

 

Is it manual or power brakes? It sounds like a bad brake booster if it is power brakes.

 

well just liek i said the brake booster was in perfect workign condition 3days ago before i took it apart and changed the cab on the truck.
thanks,
jimmy

 

Hello,
I have had this problem on two trucks now I know the feeling.
On the fords there is a lever bolted to the brake booster brkt.
It has a pivot on the bottom, the pedal rod hooks in the midle,
and the booster rod hooks to the top, and when you push the brakes this works like a rocker arm.
You have to pull the booster and master cyl off and then pull the lever and clean the pivot bushing it is probably froze up from sitting


Hope this helps ya

John Gamsjager

 

The cab you mounted did it have power brakes also and if not did you
change the brake pedal to the power brake pedal . Im not sure that that
mistake could be made!

 

78,
You said nothing about the brake booster on the first post, so easy with the attitude. Every one here works for free. You first post describes a bad brake booster. Again there is a pivot pin in the linkage that is suseptible to corrosion seizing, and this causes the pedal to stay down. It is not possible to over tighten the pivot bolt on the brake pedal because it has a shoulder on it. Try loosening it and see if it makes any difference. Do not loosen it to a point where the nut may spin off. If the booster linkage is seized you will need a torch to get it out. This usually trashes the booster. I've done three of them, personally. These trucks are right at the point where the boosters are failing. I've seen quite a few post about them lately (within the last year).
Good luck with your truck, and your attitude,
KingFisher

 

Oh i am very sorry i thaught i posted that in my first post and here it wound up being in the other post i posted so you wouldsa had to read both of them to understand that. I an very sorry for that. I gues i should read my posts alot more carefully before i reply. I am very sorry for that.

 

That's why we want user's to keep all Updated or added info to the ********original thread.*********

 

I have a slightly similar problem. Had a new booster put on about 3 years ago. Every once in a while the brake pedal doesn't come up enough to turn off the brake lights. Only seems to happen when I turn the motor off with my foot on the brake. Any ideas? (Besides the obvious, don't turn the motor off with my foot on the brake.)

 

78,
Your apology is accepted. Straighten up and fly right, mister!
Culiv,
Generally, a bad booster is the problem but:
1. Loose rear brake shoes can contribute.
2. A corroded booster piston/push rod can drag on the booster. If the push rod is out of adjustment it makes the problem worse.
3. The master cylinder has a return spring, along with system pressure, this should return the pedal to the correct position. If the MC does not create correct pressure (bad MC) or the return spring is all gummed up, you will have to replace the MC.
Good Luck,
KingFisher

 

The only thing that hasn't been replaced on the brake system (all with in about 3 months of each other) are the two front wheel cylinders and the brake lines. The booster and master cylinder were replaced as a unit. Every thing else was done prior to that. All the work by Midas (I didn't have time or weather conditions to do it myself). When the booster/master cylinder were replaced I found that the brake pedal was in a slightly different position, I had to adjust the brake light switch all the way in so that I didn't have the brake lights on all the time. Is it possible the pedal assembly is just in a bind?

 

has anyone changed the proportioning valve on the frame rail? I've changed the master and booster on my truck and have the issue of pedal staying on the floor and have to pull it back up with my foot. I know it needs a rear wheel cylinder. The old master cylinder fluid in it was nasty. Wondering if the proportioning valve is clogged or lines not allowing fluid to flow back and forth? Or would this be a vacuum issue? Does the brake pedal have a return spring on it cuz i don't see one on mine.

 

Any time you change out the power booster as a first step the following needs to be performed.