pump growls
Thread Starter
Instructor
Joined: Jan 2008
Posts: 237
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From: Newbury MA
pump growls
when i first got the car 2 years ago i had to replace the power steering pump, after i replaced it i flushed it a bunch of times and made sure everything was clean and it worked great with a rebult napa pump.
this winter i had to move the car out of the garage and noticed the power steering pump was whining like crazy but i figured it was just cold thick (but clean and new) fluid.
i starting driving the car again on friday and the pump has only gotten worse, it growns and gives no power assist and i can hear it whining when i'm driving. the fluid seems to be very bubbly and foamy, so i flushed it and put new fluid in and bled the system by turning the wheels back and forth a bunch of times with the front of the car up in the air.
the belt is not slipping either, i think its not working because the fluid is so airated that its compressing when its supposed to hold pressure, what makes fluid get foamy like that??
this winter i had to move the car out of the garage and noticed the power steering pump was whining like crazy but i figured it was just cold thick (but clean and new) fluid.
i starting driving the car again on friday and the pump has only gotten worse, it growns and gives no power assist and i can hear it whining when i'm driving. the fluid seems to be very bubbly and foamy, so i flushed it and put new fluid in and bled the system by turning the wheels back and forth a bunch of times with the front of the car up in the air.
the belt is not slipping either, i think its not working because the fluid is so airated that its compressing when its supposed to hold pressure, what makes fluid get foamy like that??
Racer
Joined: Feb 2009
Posts: 343
Likes: 0
From: San Diego CA
Le Mans Master
Joined: Jul 2000
Posts: 6,001
Likes: 113
From: Saginaw Michigan
You said that the car ran good after replacing the pump a couple years ago. All of a sudden it now has air in the system. The air is getting into the system somehow.
1. You leaked out the fresh fluid and your fluid level is low. The pump sucks in air because the level is low. This makes the fluid foamy.
2. The return line hose clamp at the pump reservoir spout is loose. It is possible for a low pressure fitting to actually suck air into the system, yet not leak oil out. Check the seal at the return pipe to the control valve as well.
3. The driveshaft seal on the replacement pump was never actually changed. It is old and hard. It just seals enough to keep oil from dripping out of the pump seal. It doesn't seal properly with the engine running and the pump sucks air into the system at the driveshaft seal.
4. You were sold a marginal pump in the first place. It went bad in only two years on the car.
Just some thoughts,
Jim
1. You leaked out the fresh fluid and your fluid level is low. The pump sucks in air because the level is low. This makes the fluid foamy.
2. The return line hose clamp at the pump reservoir spout is loose. It is possible for a low pressure fitting to actually suck air into the system, yet not leak oil out. Check the seal at the return pipe to the control valve as well.
3. The driveshaft seal on the replacement pump was never actually changed. It is old and hard. It just seals enough to keep oil from dripping out of the pump seal. It doesn't seal properly with the engine running and the pump sucks air into the system at the driveshaft seal.
4. You were sold a marginal pump in the first place. It went bad in only two years on the car.
Just some thoughts,
Jim
Thread Starter
Instructor
Joined: Jan 2008
Posts: 237
Likes: 0
From: Newbury MA
flushed and filled with transmission fluid today and no difference. i replaced the return hose yesterday. could it be a problem with the steering gear box or the valve thing?
either way napa ordered me a new pump and i'll have it on wednesday, i just dont want to be replacing pumps all the time if its not whats caused the problem.
its strange either way.
either way napa ordered me a new pump and i'll have it on wednesday, i just dont want to be replacing pumps all the time if its not whats caused the problem.
its strange either way.
Le Mans Master
Joined: Jul 2000
Posts: 6,001
Likes: 113
From: Saginaw Michigan
It can't be the gear - no hydraulic links to it.
I recommend filling the system with genuine GM power steering fluid that is available at GM dealerships. It has good antifoaming characteristics and is the only fluid that is specifically formulated to work with the Saginaw power steering pumps.
I don't think that your problem is or was caused by using non-GM power steering fluid however.
Jim
I recommend filling the system with genuine GM power steering fluid that is available at GM dealerships. It has good antifoaming characteristics and is the only fluid that is specifically formulated to work with the Saginaw power steering pumps.
I don't think that your problem is or was caused by using non-GM power steering fluid however.
Jim
Le Mans Master
Joined: Jul 2000
Posts: 6,001
Likes: 113
From: Saginaw Michigan
You have not indiciated that there has been any signs of leaking fluid.
Since both sides of the assist cylinder and the control valve see pressurized oil when you make right and left turns, I would think that those two components would demonstrate oil leaks more than just sucking in air. The pump driveshaft seal and the return hose attachment at the return spout and at the valve always have a flow of low pressure oil that could tend to suck in air if they are not sealing correctly.
Jim
Since both sides of the assist cylinder and the control valve see pressurized oil when you make right and left turns, I would think that those two components would demonstrate oil leaks more than just sucking in air. The pump driveshaft seal and the return hose attachment at the return spout and at the valve always have a flow of low pressure oil that could tend to suck in air if they are not sealing correctly.
Jim
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Le Mans Master
Joined: Jul 2000
Posts: 6,001
Likes: 113
From: Saginaw Michigan
There are o-rings inside the pump housing that seal against the sheet metal of the pump reservoir. The studs on the back of the pump have a flange section that needs to press the reservoir metal against those o-rings. They need not be supertight but need to be tightened against the reservoir back in order to seal fluid inside the reservoir.
Jim
Jim
Last edited by Jim Shea; Mar 26, 2009 at 11:02 AM.