Need brake diagnosis ASAP

[nobodyspecial]

Hey everyone, I got a quick question about my 77 F250.

I have lost the return of the brake pedal. Brakes stop the truck just as always, but the pedal stays on the floor. Pedal feel is normal, not soft, it just stays on the floor until you pull it back into the up position. It stays there until you press them again.

This happened while I was away, I just got back to it today and am wondering what it could be.

Thanks, Josh

 

[surewhynot]

I had that happen once and it turn out to be a bad brake booster.

 

[smokey]

 

[73F100Shortbed]

Sounds like a booster to me too

 

[LEB Ben]

I'll jump on the band wagon and say booster as well.

 

[Mil1ion]

I say bad Master cylinder,bad wheel cylinders/caliper pistons or weak return springs.

 

[73F100Shortbed]

I say bad Master cylinder,bad wheel cylinders/caliper pistons or weak return springs.

He says the pedal feels normal otherwise. If it was a hydraulic problem I would think he would have a soft pedal.

 

[Fordzilla80]

Subscribed.

I had this problem happen on my F100.But a few days later,the pedal decided to come back up by itself,but it's still kinda hesitant.

I'm curious to see what fixes it,so if you fix it Josh,post back up.

 

[Ranger429]

So you have to pull the pedal back up by hand? Might have broke the spring inside the brake booster.

 

[m78]

So you have to pull the pedal back up by hand? Might have broke the spring inside the brake booster.

I was going to say rusted

 

[nobodyspecial]

Thanks for the input guys, I do have one more question. Does anybody know how many pistons the brake calipers have? NAPA lists two different boosters, for 1 and 2 piston calipers.

I have been super busy, and haven't had time to investigate further. Thanks!

 

[Mil1ion]

He says the pedal feels normal otherwise. If it was a hydraulic problem I would think he would have a soft pedal.

The pedal relies on hydraulic pressure relief to push it back.

IF this truck has been sitting a while the brake shoe springs don't retract thus forceing fluid back in the MC pushing the pedal back to normal

Nothing has to leak.. it just had to Hold Up the back pressure fluid return

The job of the Booster is to ease foot pressure when applying the brakes not returning the pedal.

 

[73F100Shortbed]

I know what the function of the booster is and I still say it has something to do with the booster.

 

[TexasRho83]

Thanks for the input guys, I do have one more question. Does anybody know how many pistons the brake calipers have? NAPA lists two different boosters, for 1 and 2 piston calipers.

I have been super busy, and haven't had time to investigate further. Thanks!

My F250 has dual piston calipers.