View Full Version : Hydroboost Power Steering Flush

03-02-2024, 12:40 PM
Per manufacture suggestion, I'm flushing the power steering system before bleeding because of all new components.

I've installed a new hydroboost and steering box system. It has a dual return remote reservoir on a upgraded KCR type 2 pump. All on braided lines. I have no leaks and I double check that the lines are going where they are supposed to.

I filled the reservoir about half way and disconnected the return line from the steering box at the reservoir.

I then connected a remote starter and turn the engine over about 3-4 seconds. Then a little longer. I've done this several times. The fluid amount in the reservoir does not change and I of course have not gotten any fluid back through the return.

I've backed off the feed line at the pump and it started leaking. So I have fluid at the pump. I've let it sit. I've "slowly" turned lock to lock and have gotten no change. I don't want to keep turning the engine over and damage something.

Help and suggestions please.

03-04-2024, 02:24 PM
I'm no expert on hydroboost, but reading over this troubleshooting guide (http://www.hummerknowledgebase.com/brakes/hydroboost.pdf) it looks like the pump may be defective. Even if the unit is not properly bled there should be fluid coming out of the return.

You can also try asking at this forum. (https://www.gmt400.com) Hydroboost conversions are popular on that site, including mixing and matching different generations of braking systems there and mods like that require a deep understanding of how it works. Disclaimer - I am not a member of that forum. I'm pretty sure a lot of members from another forum I posted on (forum since shut down) when I was into GMT400/800 trucks went here.

03-07-2024, 03:59 PM
Thank you.