New hydroboost to master cylinder question

[cofferson]

I don't see anything interesting in my manual for a 08 2500 except this section about bleeding the power steering and pressurizing the accumulator.

other than that it just shows remove 4 bolts and brake switch. nothing noted about adjusting or checking anything.

And there's no adjustment so I'd have to remove the pushrod and trim.. maybe with this amount of preload they designed it to not cover the bypass port. Just seems odd since it's like 1.4mm preload. You have a gmt900 with hydroboost? If you ever get the time I'd love to know if you remove the 2 nuts holding it to the booster, wiggle it back and see if you push back onto the booster if you had a small gap when it contacts the push rod

 

[j91z28d1]

And there's no adjustment so I'd have to remove the pushrod and trim.. maybe with this amount of preload they designed it to not cover the bypass port. Just seems odd since it's like 1.4mm preload. You have a gmt900 with hydroboost? If you ever get the time I'd love to know if you remove the 2 nuts holding it to the booster, wiggle it back and see if you push back onto the booster if you had a small gap when it contacts the push rod

I don't have a 2500, sorry all my hydro boost stuff is on random equipment at work. my gmt900 is one of the hybrid ones. the regen braking system gives me a headache when I start looking into it lol. I might scrap the truck if it ever fails haha.
I just looked up 08 2500 in prodamand before a left work real quick. that's where that pic came from. didn't seem to have much info about it. mostly the vacuum booster trucks.


I would guess you're right thou, if the original was like that and the new ones you got were the same. most likely it's designed that way for who knows what reason. sorry if you shortened your new one and it was supposed to be longer.

 

[cofferson]

It's all good. I used the rod from the original booster in the new one once I got them apart. Doesn't really matter because I have another thread open where the brakes are unbleedable after replacing the master for some reason. Got another ACDelco master cylinder bench bled and on the truck today and still can't get any bubbles at any calipers. Pretty much everything is new now so I'm guessing I have to swap out the ABS valve block which I really didn't want to have to do. I can run the ABS auto bleed but I should have at least got a firm pedal without doing that and then get air out of abs then bleed again..