GM Brake Options/Booster Mismatch

[Overbored]

 

I've got a good looking, good running, booster leaking, 94 Silverado heavy duty K2500 with brake option code JB7.

It's a 4x4, has 13 x 2 1/2 eight lug drums, 8600 GVW, 5.7. All the things that make it a JB7. ( Plus the sticker in the glove box.) I bought it in 2007.

I ordered a booster from a local auto parts store using the JB7 code & discovered ( the hard way ) that the pushrod hole was too small to fit the brake pedal stud.

Went to a different store that had some boosters in stock & found that option JB6 had a larger hole & would fit the pedal. With some misgivings, I bought & installed that one.

It's defective.

The outer case halves seperate slightly when the pedal is pressed so the master cylinder & brake lines move forward about 1/8th inch. The brakes work but it makes brake action really touchy & brake release slightly delayed.

The truck's drivable, so before getting another booster, I'd sure appreciate hearing from anyone that's replaced this booster & if you had any problems with the job & with parts.

Also, I'm looking for the best way to get the dang pushrod retainer clip off of the brakepedal stud. It took about three hours last time...

Edited August 20, 2020 by Overbored
Eliminate uneccesary comments. Add specifics.