Never in my years as a shop tech or on my own stuff have i ever had to vac a p/s system .
Sounds like a dead pump .
Sounds like a dead pump .
CK5
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Can you vacuum bleed a hydroboost setup?
- Thread starter HankScorpio
- Start date
Kind of what I think now. Never had this trouble with my other hydroboosts or pumps. This is the first time the manual suggested a vacuum bleed procedure, figured it was just a van hydroboost thing. Now I think it has to be a dead pump. Its moving fluid but it cant be building enough pressure. If it was a bad steering gear I should have decent brake pedal, which I don't.
If you take that pump out stick it in a vise fit a Allen key socket in the shaft. Brief trigger squeeze on 3/8 air ratchet, or like, oil should shoot across the shop.
A 1200 psi guage and 1500 psi hose is all you need to test it.
You can even adapt gauge to the existing pump pressure hose. Don't use the engine to test, remove belt and turn with and air ratchet
A 1200 psi guage and 1500 psi hose is all you need to test it.
You can even adapt gauge to the existing pump pressure hose. Don't use the engine to test, remove belt and turn with and air ratchet
How can the system introduce air to the oil without ever letting oil leak out? It should only see vacuum when the system is cooling off.
So you have 2 symptoms? Foam in the oil and no assist? I can see severe aeration as causing little/no assist, but a little air usually just causes noise. If there's no assist, maybe you have debris in something. That remote reservoir should be your friend, since it's the high point in the system. With just the pump-mounted reservoir, I always wonder if the bubbles escaping the oil will sit in the hydroboost lines, waiting to make more foam next time it's started.
If you had the right hoses you could bypass the hydroboost or the steering for troubleshooting. Without the right hoses it's a bad idea due to the really high pressure.
So you have 2 symptoms? Foam in the oil and no assist? I can see severe aeration as causing little/no assist, but a little air usually just causes noise. If there's no assist, maybe you have debris in something. That remote reservoir should be your friend, since it's the high point in the system. With just the pump-mounted reservoir, I always wonder if the bubbles escaping the oil will sit in the hydroboost lines, waiting to make more foam next time it's started.
If you had the right hoses you could bypass the hydroboost or the steering for troubleshooting. Without the right hoses it's a bad idea due to the really high pressure.
This last round of vacuum bleeding I really thought I had it. I heard it burp a bit when I turned the wheels under vacuum. When I drove it no assist but also no bubbles. It did not foam and the fluid level stayed consistent. This led me to believe I got a bad pump. Reman from O'Reilly. Just picked up a "new" cardone unit. Going to install it hopefully tonight. Being a van it's the one thing I didn't want to do again. I sure hope this works. Going to make sure everything is as full of fluid as possible as I reassemble. May do the vacuum bleed right from the beginning and hope it works properly this time. I hear way too many stories about dead remans right out of the box while trying to work through this. Wish I had done differently. One of those deals where the reman was on the shelf and napa was closed.
It's mounted low on the driver's side. The suspension and crossmember prevent access from below. The procedure for changing the pump includes loosening the accessory brackets from the engine just to get it to move. If I am going back in the whole pump is coming out.
Is this a 350 g van? On the ambulance we would pull the crank pulley, then the fan and clutch, shroud will come out now.
We would water pumps from below. Might work for ps pump.
Might not. Also this was done on lift
We would water pumps from below. Might work for ps pump.
Might not. Also this was done on lift
No, GMC Safari. Mid sized van so its a 4.3 stuffed in where it barely fits. AWD too so lots of stuff crammed into a small package.
Ah, I little to none actual awd astro van experience. Only 2wd.
