brake bleeding question.

[Ontheboulder]

hey there, ok well after some serious head scratching I have determined that my 87 GMC had the wrong master cylinder for the JB7 brake system,just installed a iron master cylinder to replace the aluminum and plastic one. all bench bled with no bubbles after and now on the truck, question does the master cylinder need to be level while bleeding aat the wheels?? seems i've heard that from someplace along the way.we all know its at an incline when mounted and Ive bled many other rigs without jacking up the rear to level things out,just a quesstion in my head, Thanks

 

[Blue Ox]

If it's fully and properly bench bled, no. As long as you don't let the level get low while you're bleeding it.

 

[Edelbrock]

Are you having issues bleeding the brakes? Squishy peddle?

 

[Ontheboulder]

Are you having issues bleeding the brakes? Squishy peddle?

not yet, I replaced everything a few years ago but have put no miles on it,just sat there,finally getting back to work on it,I replaced the brake booster a few days ago and the pedal felt weird. did some research and realized that it had the wrong master cylinder for the JB7 brake system.SO I replaced it with the iron reservoir master cylinder, I did notice that the brake line locations are swapped with the different master cylinders, I remember after I installed the first master cylinder that it seemed to not have good fluid pressure at the rear bleeders when it was being bled

 

[Ontheboulder]

If it's fully and properly bench bled, no. As long as you don't let the level get low while you're bleeding it.

Thanks, I really didn't think so and I have worked on these trucks for a long time off and on over the years! just seems I heard of jacking the rear up to level the master cylinder from some place or could be a voice in my head giving me S$%t !!!