Looking into converting my truck to hydroboost. I know its probably a longshot and probably no one's done it before, but im really tired of dealing with the unpredictable, delayed, mushy, solid, then mushy again brake master cylinder in my truck. Ive gone through the whole braking system and replaced the whole master cylinder. There are no leaks, but after a week or two of bleeding, it seems that air gets into the abs system. At this point im pretty sure its just how they are. Slamming on the brakes to trigger abs or doing an abs rebleed solves the issue for about two weeks before it comes back again. It's really a pain in the *** and borderline dangerous in atlanta traffic sometimes. It has always been this way since been driving the truck for the last 4 years and my parents complained about the same thing when they drove it for the 4 years before that.

Does anyone know anything about what it would take to convert this truck? It has to be possible since other trucks of the generation used hydroboost, and the h2 in previous years used hydroboost. The big issue with this is getting the abs to work since I would have to find a pump module that works with hydroboost and can communicate with the truck over the network, but it should be possible right?

 

Did you use a scan tool to bleed the master cyl? I'm not that smart, I read it in another post.

 

It'll be hard to make it all work without it being an option at some point for the 08/09 but there is always someone out there that can figure it out.

I'll add that my truck has always had solid brakes, predictable and consistent for the time that I've owned it.

Neal

 

well what did the other GM trucks use for 08/09 maybe you can duplicate one of those setups.

 

I have an 09 H2. Had by break fluid flushed and refilled last year. My Mechanic used A pro scanner and went thru the process. I know that part of the scanner process triggers the ABS Motor and runs it for a bit which we heard come on. Prior to coming to him the breaks have allways been good with a High hard pedal. After the flush they seened at tiny bit better.
Not sure about weather or not they used a Hydor boost syetm in the stock 09 or not.

 

That should be an easy conversion but IMHO the electric pump sytem you have now would be as good if not better than hyrdoboost.
Look for universal systems for Chevy trucks. I can't think of the name off the top of my head but I know Classic Performance has them.

The electric system still has a vacuum assist and that might be part of your issue. Check the system completely and replace the valve. Also look at the rubber brake lines and replace with S/S. I'm not sure on an 08/09 but you could also have a vacuum pump that is notorious for what you ae describing on newer trucks and SUV's. Search the Tahoe/Yukno chat board for some tips.
TH

 

yeah I’ve done ss brake lines all around and I replaced the whole master cyl/booster combo with a brand new one. There is no vacuum assist on this year at all. Everything is all self contained in one unit on the firewall. It’s got an electric pump that builds hydraulic pressure in an accumulator similar to hydroboost but instead of just assisting the brakes, the master just sends pressure to a sensor that reads pressure and releases hydraulic pressure to the brakes accordingly. It’s almost brake by wire.

The only thing I don’t understand is how it determines what the pedal should feel like.



this is what the unit looks like. This is my old one when it was still in there.

 

I just flipped through the service manual and there are some simple steps that I didn’t follow exactly and maybe that’s part of my issue. I’ll redo it all this weekend and see if it makes a difference.

 

I just replaced the master brake cylinder assembly on my 2008 H2. What are the simple steps listed in the service manual to properly bleed the brake system?

 

How much did the unit cost and what's the correct name to order it?