"new" hydroboost unit for 87 K5

[plugugly]

my sons 87 K5 has a leaking hydro brake booster. I just had hip surgery, so i cannot be too much help for him in replacing it, other than siting and watching.

All the replacements for 80s chevys are remanufactured units, which if you know HB units, have a VERY poor track record of working. I would like to buy a new booster for a modern truck IF they can swap over, fix it once, and have it last at least many years before have to swap again. Best I can tell, the 2000 plus units look pretty close, other than the pushrod length. I do have a new unit sitting on the bench that I "borrowed" from amazon. It already has the star and pushrod inside it, and the brake to pedal rod is longer than the blazer. Ive had someone recommend a GM 178-1036. In reasearching that, I found the 178-1037 which is cheaper.

Anyone have any experience in trying to find a newer HB?

 

[Cucv_M1008]

I had my original rebuilt for under 200. It was the best option imo.

 

[tarussell]

I don’t know how to link a thread to another so here is a pic of what to search for - some very good HB info and cures for inferior seals within it.

Maybe one of the Moderators could link it for ya’ - their all really good at that stuff.

 

[Blue85]

https://ck5.com/forums/threads/hydro-brake-booster-rebuild-kit.344472/#post-4204166
https://ck5.com/forums/threads/leaky-hydroboost.339681/#post-4064222

 

[tarussell]

https://ck5.com/forums/threads/hydro-brake-booster-rebuild-kit.344472/#post-4204166
https://ck5.com/forums/threads/leaky-hydroboost.339681/#post-4064222

That’s the one I was actually looking for - good info.

 

[plugugly]

been doing some reasearch. Someone had mentioned a GM 178-1036. it led me down the rabbit hole of searching. was able to find a 178-1037, which durmax folks say is the "new' version of the 1036, and about 30 bucks cheaper. I have a few pics compared to the stock K5 unit. It seems to be pretty much spot on except for two points. The pedal pushroad hole is .2" smaller (6.34 for k5 and 6.21 for this 2011 unit), and more importantly, the booster to MC pushrod is about 1/4" too long. Not sure if the 1036 i was told about would be any different, but I didnt want to buy one from amazon as you cant return it. I imagine I can just swap the pushrod from the K5 to this new booster, but I can not verify that as I dont have mine pulled from. I have some pics, but cant seem to add them as I dont have anywhere to post them

 

[Wes Harden]

iirc the push rod to master cylinder will exchange. I have change the pedal push rod in the past is not easy but can be done. Have a used 178-1029 on the self in the shop I can check if the rod comes out.

​

 

[plugugly]

pedal push road 'should' pop out and in with a quick bang with a mallet. Ive heard of folks braking the crimped 'housing', but have never had that problem personally.

I havent played with HB for many years, and have really forgotten a lot about it. I konw that when I bought my Vanco kit 15 years ago, there was some mention of what to do with measuring and 'adjusting' the HB to MC pushrod, but for the life of me, I cannot find that info. Dont recall if it was a matter of replacing the rod, or just taking some material off.