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In search of...Hydroboost

Suprdave1

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It is not. I spoke to several people that had installed these units on their Chevelles and the spring and retainer were not in theirs. You can't find them anywhere as a separate part so I went to the junkyard and bought another unit for $50! It has the spring and retainer, but the pushrod is too short. Not a problem as I made one for mine anyway. I may just put that unit on and see what happens.
 

Stoney

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Kind of off subject... Will glazed drum brakes stick?? As in will it make them drag if they're glazed?
 

Stoney

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You know Dave I was wondering about that because I have a hydroboost pump that came off at a different truck.... I was kind of wondering if I could put it on mine even though it's not the right one...just kind of figured with all the problems my truck has had I didn't want to screw it up worse LOL
 

Suprdave1

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May have found the problem. Took the pressure hose from the pump off the hydroboost to drain fluid. Started engine....NO PRESSURE AT ALL FROM THE NEW PUMP...🤬🤬🤬
 

Stoney

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I'm only asking because I didn't have any problems with my hydroboost until after I put a new power steering pump in..
 

THEFERMANATOR

FRANKENBURBAN
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FYI, the hydroboost power steering pump is different than a regular pump. There's more to it than just having 2 return ports. The pressure relief spring is different, there is an extra spacer on the pressure valve, and the orifice is sized differently for extra flow. And I had a pump years back not pump fluid no matter what I did. I found I had left the magnet out inside the pump, didn't think it would have anything to do with it, but I put the magnet back in, and the pump worked flawlessly afterwards.

As to the hydroboost pulling the pedal down, did you rebuild this hydroboost unit or open it up? The accumulator wouldn't cause any of these issues, it's only there to supply 1 or 2 applications of the pedal with power assist with the engine off. Now if you opened this hydroboost, you may have not gotten the spool valve installed properly, and it's boosting when it shouldn't. There is a fork you have to install in the spool valve correctly, if not, it will boost all the time. I've done a few of these now, and it's a job that requires patience and paying attention to get done right
 

Stoney

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In the first paragraph furminator when you're talkin about the relief spring and orifice etc are you referring to on the back of the power steering pump where the high pressure line goes in?? I am asking because I eliminated all of that and ran a high pressure line from a 1995 ( mines a 97) and eliminated the Evo valve...
 

Suprdave1

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FYI, the hydroboost power steering pump is different than a regular pump. There's more to it than just having 2 return ports. The pressure relief spring is different, there is an extra spacer on the pressure valve, and the orifice is sized differently for extra flow. And I had a pump years back not pump fluid no matter what I did. I found I had left the magnet out inside the pump, didn't think it would have anything to do with it, but I put the magnet back in, and the pump worked flawlessly afterwards.

As to the hydroboost pulling the pedal down, did you rebuild this hydroboost unit or open it up? The accumulator wouldn't cause any of these issues, it's only there to supply 1 or 2 applications of the pedal with power assist with the engine off. Now if you opened this hydroboost, you may have not gotten the spool valve installed properly, and it's boosting when it shouldn't. There is a fork you have to install in the spool valve correctly, if not, it will boost all the time. I've done a few of these now, and it's a job that requires patience and paying attention to get done right
Never took the hydroboost apart. I knew about the pressure valve, but I have talked to some others that said they used the stock pump IDK! Just trying to work out bugs. The pump appears that it never pumped fluid to the hydroboost, only recirculated it in the reservoir. I first took the return line off the hydroboost and got nothing out with the engine cranking over. I then took the pressure hose off the hydroboost to see if I had an air lock and cranked it over, no fluid came out. I then started the engine and still got no fluid. I surmised the pump is bad!!
 

WarWagon

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IIRC WW had bad reman power steering pumps take out the entire system. Dusted it with metal shavings
Advance. It has a warranty
You will need to check the oil in the system now for debris.

I run a filter on the return line from the PS box. (A filter on the hydro-boost return can be a restriction that keeps the brakes applied.)

Old School I guess...


New design:


:banghead: IMO There is only 2 ways to get a working PS pump. Virgin NEW or out of a junkyard from a clear wrecked vehicle. A wreck was running at the moment of impact so the odds are better that the PS pump worked at the time.

Repaired, rebuilt... aka repainted broken scrap metal that isn't fixed. You have better odds winning at a casino than getting a rebuilt PS pump that was rebuilt properly.

I had one pump start leaking on the alignment rack because the shaft wasn't touching the seal on one side sudden like. The shaft moved because the bearing let it move and all the bearing metal had to go somewhere. It ran for 30 min total since install. The oil was a glitter globe. I replaced everything, flushed the cooler, and put a filter on the return from the steering box. @ak diesel driver is correct: big job to replace the box, hydro-booster, and blasted PS pump again. I went through 5 PS pumps with one DOA like yours before I figured out the above way to obtain a working PS pump.

Pic on post 12 of bearing clearance you can see...

 

FellowTraveler

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You will need to check the oil in the system now for debris.

I run a filter on the return line from the PS box. (A filter on the hydro-boost return can be a restriction that keeps the brakes applied.)

Old School I guess...


New design:


:banghead: IMO There is only 2 ways to get a working PS pump. Virgin NEW or out of a junkyard from a clear wrecked vehicle. A wreck was running at the moment of impact so the odds are better that the PS pump worked at the time.

Repaired, rebuilt... aka repainted broken scrap metal that isn't fixed. You have better odds winning at a casino than getting a rebuilt PS pump that was rebuilt properly.

I had one pump start leaking on the alignment rack because the shaft wasn't touching the seal on one side sudden like. The shaft moved because the bearing let it move and all the bearing metal had to go somewhere. It ran for 30 min total since install. The oil was a glitter globe. I replaced everything, flushed the cooler, and put a filter on the return from the steering box. @ak diesel driver is correct: big job to replace the box, hydro-booster, and blasted PS pump again. I went through 5 PS pumps with one DOA like yours before I figured out the above way to obtain a working PS pump.

Pic on post 12 of bearing clearance you can see...

I run them on both return lines....
 

Suprdave1

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Ok, update. Took someone's advice above, not sure who, but thanks. I swapped my old pump for a pump for a 2000 Silverado 2500 diesel. It came with dual return lines that fit perfectly in the mounting bracket. Flushed and filled with new fluid and left the hose loose from the pump to the hydroboost and started bleeding. Cranked engine over, no start to cycle fluid, cranked steering wheel back and forth and pumped brake pedal several times. No bubbles ;-) started engine and actually got fluid from the pressure line! I have a cooler and filter on the way to install. I'm installing the filter and cooler in the return line from the gearbox and then back to bleeding. This may actually work !!! I think the reason the pedal was sucked to the floor as it was getting vacuum from the gearbox return sucking the hydroboost return...IDK, but it may work!!
 

Suprdave1

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I thought I had updated, but apparently not. I removed the return line from the hydroboost and started the engine and NOTHING came out The pump is bad even though it was NEW! I swapped it with one form a 1998 chevy diesel with 2 return lines. Installed it and everything bled perfectly!
 
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