Brake booster not pushing brake pedal out enough

[TB]

I recently installed a new brake booster in my 01 XLS Explorer. I bought one from NAPA. I've noticed that when you're doing stoplight driving and using the brakes on and off, the pedal wants to not come back all the way and it lets the brakes kinda drag(you can feel it).

I hafta put my foot under the brake pedal and pull up about half an inch to fix this.

What could be causing this? I tried switching out that one way valve on the booster, but that made no difference.

My redneck side of me is saying just buy a spring and rig it up somehow to pull it back out.

Anyone else have this issue?

 

[Cobraguy]

It almost sounds like you have an internal leak in the booster...especially if the brakes don't release and drag.

But first, double check that your rod from your pedal to the booster is adjusted properly, and that your adjustment is correct between the booster and the master cylinder. If those are good, then I would get a new booster. But if they aren't correct, they could cause something like this.

 

[TB]

It almost sounds like you have an internal leak in the booster...especially if the brakes don't release and drag.

But first, double check that your rod from your pedal to the booster is adjusted properly, and that your adjustment is correct between the booster and the master cylinder. If those are good, then I would get a new booster. But if they aren't correct, they could cause something like this.

Please forgive my ignorance, but you can adjust that "arm" that extends out of the booster that connets to the actual brake pedal?

I'm sure the booster doesn't have a leak, as my idle is good and the brakes work great...better than before my OE booster went out.

If that arm is adjustable, thats probably my root cause.

Thanks for the advice!

 

[Cobraguy]

All rods need to be adjusted correctly, even if the rod is not adjustable. Some rods are adjustable, some come in different lengths, and some need to be ground down to fit. Regardless, you need to check those and make sure you are good.

An internal leak would not necessarily cause idle issues. Take a look at the internal pieces and operation of one and you should see what I mean.

 

[TB]

I'll try to find some time this week to get under there and re-examine things. Thanks for the tips.

 

[my98nnj]

I would think the master cylinder is what brings the pedal back, not the booster.

 

[TB]

I would think the master cylinder is what brings the pedal back, not the booster.

It does push it back....but if the rod(like he said)is too short it can't push it back all the way.

It's got to be the booster part. Thats the only thing that was changed.