Hydroboost, ps for cummins swap - help!

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grampsbutler

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Location
San Diego, CA
First Name
Graham
Truck Year
1984
Truck Model
K10 Suburban
Engine Size
6.2l Diesel
Background: I have an 84 Suburban which I have swapped in a third gen cummins out of a 2011 Dodge. The Burb originally had hydroboost. I went with the dodge power steering pump. Everything is plumbed corretly, but I am having a hard time getting it to bleed / work.

Any pointers? Is the dodge pump compatible with the GM hydroboost? from what I understand it should be.....~1800 PSI @ 3-4 GPM.....

Symptoms are like it has a ton of air. Steering is non-assisted, and I can hear cavitation in the pump, but no matter what I do, I cant seem to get more air out. Could it be that my hydroboost is bad? has anyone on this board done this set up?
 

MarineOne

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Western New York
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David
Truck Year
1986
Truck Model
K25
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454
Background: I have an 84 Suburban which I have swapped in a third gen cummins out of a 2011 Dodge. The Burb originally had hydroboost. I went with the dodge power steering pump. Everything is plumbed corretly, but I am having a hard time getting it to bleed / work.

Any pointers? Is the dodge pump compatible with the GM hydroboost? from what I understand it should be.....~1800 PSI @ 3-4 GPM.....

Symptoms are like it has a ton of air. Steering is non-assisted, and I can hear cavitation in the pump, but no matter what I do, I cant seem to get more air out. Could it be that my hydroboost is bad? has anyone on this board done this set up?
it shouldn't be an issue try cracking lines at hydro boost while truck running
 

mitch2029

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Mitch
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76,78,80
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k20
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5.9 cummins
I had luck priming by jacking up the front of the truck just enough to get the weight off the front wheels, topping off the fluid in the pump and slowly turning the steering wheel both directions, first without the engine running and then some more rotations with it running. Maybe 5 minutes total. Set it down and good to go
 

grampsbutler

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San Diego, CA
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Graham
Truck Year
1984
Truck Model
K10 Suburban
Engine Size
6.2l Diesel
I am closing the loop on this for the benefit of others who may have the same issue.

The problem was with the pressure regulator inside the dodge pump. If you take it apart there is a nut holding the high pressure relief spring valve in position. It had backed out which caused the pressure relief valve to be always open, which is why I wasn't getting sufficient pressure in the system for steering or brakes. The fact that it was open was causing the pump to recirculate fluid at a high rate, which accounts for the cavitation sound.

I used some thread locker, tightened it up and, like magic, I have brakes and steering. It now sounds healthy.

This is an example of a factory quality control fail. The pump was brand new and there is nothing wrong with it, but poor assembly controls caused me to spend days figuring out what was wrong.
 

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