power steering glitch

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tmoretta
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power steering glitch

Post by tmoretta »

Sometimes the power steering on my '88 M6 is inoperative (gets stiff) after coming to a stop and the engine is at idle. Should I increase the idle or some better fix?
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hornhospital
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Re: power steering glitch

Post by hornhospital »

Fluid level correct?
Power steering drive belt tight and in good condition?
Ken Kanne
'84 633CSi "Sylvia"; '85 635CSi "Katja";'85 325e "Hazel Ann"; '95 M3 "Ashlyn"
tmoretta
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Re: power steering glitch

Post by tmoretta »

Yes, I think both are fine. I hesitate to add fluid as, multiple times, reservoir has overflowed.
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hornhospital
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Re: power steering glitch

Post by hornhospital »

If it overflows you're doing it wrong.
You shut the engine off, then press the brake pedal about 20 times, until it goes rock hard. That discharges the "brake bomb", and the reservoir will be filled with fluid. You fill it to within 10mm of the top. That's it. When you start the engine you will have to pump the brake a few times to get a normal feel, but it will return.

The power brakes and power steering operate from the same pump and fluid reservoir (not the brake hydraulic system). One affects the other. Your description suggests that either the drive belt is slipping or the pump is failing, that is it's not delivering full pressure.
Ken Kanne
'84 633CSi "Sylvia"; '85 635CSi "Katja";'85 325e "Hazel Ann"; '95 M3 "Ashlyn"
tmoretta
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Re: power steering glitch

Post by tmoretta »

Why would the belt slip at idle rather than at higher RPM?
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hornhospital
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Re: power steering glitch

Post by hornhospital »

It takes the same amount of hp to spin the pump regardless of engine speed. At idle the pump doesn't have the momentum it does at higher rpm, so it's more likely to slip the belt when you increase the resistance by turning the wheel.
Ken Kanne
'84 633CSi "Sylvia"; '85 635CSi "Katja";'85 325e "Hazel Ann"; '95 M3 "Ashlyn"
tmoretta
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Re: power steering glitch

Post by tmoretta »

Anyone know of a source for power steering pump parts or rebuild? FCP Euro has one for almost $500. Is the "shark" M6 pump same as any other model for less money?
bpoliakoff
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Re: power steering glitch

Post by bpoliakoff »

Contact Jay Stratton, JCS on this forum.. He is the best rebuilder for these pumps
81 Euro 635 M90 with motronic. Currently under a complete nut and bolt restoration. Pictures at
flickr.com/photos/bertsphotos.
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Re: power steering glitch

Post by tmoretta »

Yes, thanks , I will. However, I have already changed/rebuilt the o-rings etc. because of a leak. It must be impeller parts that are failing.
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JCS
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Re: power steering glitch

Post by JCS »

bpoliakoff wrote: Wed Jun 23, 2021 11:44 pm Contact Jay Stratton, JCS on this forum.. He is the best rebuilder for these pumps
Thanks Bert,
I have already quoted a PS Hydro Gear Box repair 18 months ago, with T Moretta,
and he never gave me his address, so i could quote return shipping, on his Hydro.
I never finished his quote.
If he wants a PSP rebuilt, he already knows me.
Jay
Jay
'88 M6, Red/Tan
My NEW Website https://www.jaysbmwparts.com/
tmoretta
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Re: power steering glitch

Post by tmoretta »

I have carefully/correctly filled the reservoir, tightened the power steering belt. The symptom still persists. Steering box faulty, weak pump, brake bomb, etc? Symptom only off throttle - coming to a stop, especially while turning.
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hornhospital
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Re: power steering glitch

Post by hornhospital »

Sounds like a weak pump to me.
Ken Kanne
'84 633CSi "Sylvia"; '85 635CSi "Katja";'85 325e "Hazel Ann"; '95 M3 "Ashlyn"
tmoretta
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Re: power steering glitch

Post by tmoretta »

I am attempting to source a new power steer. pump. Anyone know why the pump for a 635CSI/M6 is so much more expensive than other "shark" models? Would a pump for a 633, for example, fit fine? Is there a difference in pressure etc, or is it just marketing?
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