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No power steering below 2000 rpm

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70383ChargerSE

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Recently ran into a problem with my power steering pump on my 70 Charger. Went for a drive and tried to turn into my driveway and had no power steering. I eventually got the car parked. Shut it off and had the same problem but if I revved up the engine to 2000 rpm, my power steering came back but then went away at idle. I have no leaks, just changed the return hose (after I discovered a leak) and that's all that has changed other than new belts after a power steering belt squeal. Is my pump bad or is it my gear box?
 
Are you sure the new belt is tight enough? Fluid level low? Maybe an air pocket in the system? Jack up the front wheels, and with the engine idling, turn the wheels lock to lock a few times. That might bleed out an air pocket. Then re-check fluid level. It's worth a try.
 
70383ChargerSE said:
Recently ran into a problem with my power steering pump on my 70 Charger. Went for a drive and tried to turn into my driveway and had no power steering. I eventually got the car parked. Shut it off and had the same problem but if I revved up the engine to 2000 rpm, my power steering came back but then went away at idle. I have no leaks, just changed the return hose (after I discovered a leak) and that's all that has changed other than new belts after a power steering belt squeal. Is my pump bad or is it my gear box?
Click to expand...
Simple question but, has the new belt stretched?
Mike
 
Thanks for the replies, the belt tension is correct, fluid level is where it should be. I am thinking checking the pressure from the pump and seeing if it is putting out what it should be.
 
70383ChargerSE said:
Thanks for the replies, the belt tension is correct, fluid level is where it should be. I am thinking checking the pressure from the pump and seeing if it is putting out what it should be.
Click to expand...
Did you attempt to bleed air as I posted yesterday?
 
What was wrong with the old return hose, Rotted and cracking, starting to flake off, is the pump and steering box new-ish or just old and still working?

Ive found that on some of the pumps there is a small fine mesh screen on the inside of the high pressure fitting on the pump. You have to pull the big nut off and then disassemble to get to the screen....but they can clog up from crud and debris and cause a low pressure issue at low RPM due to the restriction.
 
IMO....what pump do you have? FEDERAL or TRW or GM/ Saginaw......the flow conttol valve or high pressure relief valve are different depending on the pump manufacturer. The Saginaw pump is a vane pump, the Federal pump is a cam and roller design. Hopefully, when you refilled and blead the system, you used a hydraulic oil and not ATF. The FSM shows the correct pressures for each design pump and the correct internal components. The pumps are simple devices and are easily rebuild able, should you choose to do so. Identify the pump you have and go from there.....
BOB RENTON
 
I had a Federal pump that went out and I had the same symptom.
I fitted a Saginaw pump and flushed some oil through as the Federal pump had circulated metal bits.
All still working OK.
 
Thanks for all of your replies but I am kind of stumped. I jacked up the front end and turned the vehicle steering wheel left to right, made sure the correct fluid is being used, no air pockets. This is a Saginaw pump. Pulley alignment is good. If I drive the car normal (obey speed limits) there is no issue. If I take off hard and go up to about 85 or so, and try to make a turn as I slow down, I lose the power assist. Scary.
Once the car cools down, I get my power assist back. This is a stock 440 Charger with ceramic coated headers. When I touch the power steering box it is very hot, fluid isn't boiling from what I can see but I don't know where to go from here. Belt still slips at WOT. During normal driving. No issue. I have drained and flushed the fluid. Is my power steering gear box the next step?
 
It sounds like you may have a jamming pressure release valve in the pump.
 
Is this the pressure relief valve?

16495350986741292393047282645566.jpg 16495351121942579106592007508540.jpg
 
No I don't think so.
I am no expert but I think it is at the back of the pump housing.
 
The Saginaw pump uses a combination flow control valve/high pressure relief valve. This valve performed two different functions. The flow control valve regulates the pump's oil flow to prevent overheating the oil under normal circumstances. The high pressure relief valve determines the maximum pressure the pump produces, typically 1500 psi with the wheels against the travel stops as in parking maneuvers. IMO, it is highly likely that the flow control valve is causing your difficulties. It is located INSIDE the pump housing, mear the outlet fitting connection. The FSM will show the exact location. Depending on the engine and final gear ratio, if the final gear ratio was 3.54:1 or greater, a oil to air heat exchanger was installed on the steering box to pump's return line as part of the the pump's mounting bracket. Just my opinion of course.....
BOB RENTON
 
Thanks guys for the quick responses. I am going to change it out, replace it and see what happens. This plunger with spring was pretty much jammed in there. I would imagine it shouldn't be so difficult to remove.

16495368544138159274058694112255.jpg
 
70383ChargerSE said:
Thanks guys for the quick responses. I am going to change it out, replace it and see what happens. This plunger with spring was pretty much jammed in there. I would imagine it shouldn't be so difficult to remove.

View attachment 1267231
Click to expand...
That will need to be adjusted if you didn't mark the location of the outer housing. Do not start the engine with your arm through the steering wheel! Do you have a FSM?
Mike
 
Thank you for letting me know and the warning. I do have a FSM but am having difficulty understanding the adjustment process? Anyone able to help out with that? Any tips or suggestions? Should this adjustment be done with the car on the ground or up in the air? Thanks in advance
 
Up in the air is best. Mount it back on and you'll note it can slide front to back. Install it about center and tighten the bolts but not fully. Then the procedure is to start the car and gently tap the control valve with a hammer either towards the back of the car or towards the front until the power steering normalizes with the front wheels in the straight ahead position.
If the valve is not adjusted correctly it will force the front wheels either to the right or to the left.
Then you tighten the mounting bolts to spec.
 
Awesome. Thank you for explaing that to me and again, thank you to everyone who has responded so quickly to explain and guide me in trying to find the root issue with my steering. When my 1 year old wakes up from his nap, I will get going on this lol. Thank you.
 
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