I didn't remove the high and low pressure lines from the pump...maybe that is the issue??

 

Take your hoses out, and go back to step 1 and follow carefully, checking off whats been done. you've probably missed something simple, and it's holding you up. report back if you still can't figure it out

 

I know I have a PDF manual of hydroboost rebuild and I cant find it. :confuzeld

so far just this one, which is basic.

View attachment hydeoboost install.pdf

This one in the FAQs gives breakdown and diagnosing http://www.dieselplace.com/forum/at...qs-master-list-information-6-2-answers-gm_stg_15000_01_1_base_brake_systems.pdf

 

Try from page 69 on and see if it helps.

http://www.dieselplace.com/forum/at...9927120-6-5l-faqs-master-list-information-6-5-answers-1994-section-5-brakes.pdf

 

Thanks guys.

Has anyone actually taken it apart and could chime in?

 

http://www.dieselplace.com/forum/63...forum/63-gm-diesel-engines/21-6-5l-diesel-engine/44771-rebuild-hydro-boost.html

 

I can probably get you a blow up diagram...but thats about all I've got for ya here, lemme know

 

Having issue with brakes not working after replacing figure 8 seal and piston seal. Brake pedal falls down and stays there. I can push it farther to the floor to put it into gear. I have auto trans. I put it into gear and the truck won't move, like the brakes are locked up or something.

 

I don't have pictures of what i'm talking about but the piston has a part that slides into another piece that connects to the rod going to the pedal. Its kinda a pain to get lined up with the unit in the truck. When I did mine a month or so ago I had the same issue.

 

Smdk2500

Obviously you took it back apart?

 

Replaced that seal years ago. The thing is, that's not really what's leaking most likely. My leak was the seal on the piston. It was leaking out the weep hole. I had a lot of other work to do, and no money so I did replace the seals. The bore was pretty scratched up so it only lasted about a year or so and started leaking again. Bought a cheap hydro boost that then blew up on us near the Colorado boarder. Took out the power steering pump. I'm done with cheap chi com parts for the hydro boost and spent over a grand for delco pump and booster a few months ago because we're going to Mexico in November and I don't want any more problems.

also, you can get the front off the booster without removing it from the firewall. Make sure you pump down the accumulator first. assuming it holds any pressure.

 

Replaced that seal years ago. The thing is, that's not really what's leaking most likely. My leak was the seal on the piston. It was leaking out the weep hole. I had a lot of other work to do, and no money so I did replace the seals. The bore was pretty scratched up so it only lasted about a year or so and started leaking again. Bought a cheap hydro boost that then blew up on us near the Colorado boarder. Took out the power steering pump. I'm done with cheap chi com parts for the hydro boost and spent over a grand for delco pump and booster a few months ago because we're going to Mexico in November and I don't want any more problems.

also, you can get the front off the booster without removing it from the firewall. Make sure you pump down the accumulator first. assuming it holds any pressure.

Mine was leaking through weep hole to. Got a reseal kit off Amazon. Tore into it the other day. Just the front, not the whole thing. Pretty dirty in there. Cleaned everything with denatured alcohol. Took a q tip to housing on fire wall and had chunks of crap like chips, cleaned all of it. Replaced figure 8 seal and piston seal and O ring on flare hose that fell off. Put back together and brake pedal went inverted. Took it back apart and noticed where I missed lining up the head on the lever of piston. The two ears on the lever go in that channel on the end of spool assembly. Oh and accumulater check valve parts fell out second time. The kit came with some new parts and I replaced them to. Still leaking through weep hole. I am not seeing much or any fluid levels in change in power steering resivor or losing any in brake fluid resivor either. Been a little bit of a bear. Trying to get past this repair to get to others. Like cooling stack degrease and rinse and others. Life of a old truck owner. Gotta love it!

 

Sucks that you really can't find a reasonably priced, half ass quality Hydro boost. Delco is the only hope. $700

 

😱$ And then I have to pull the rod out of mine and replace in 700$ part