I've never experienced this. Friends 92 300D 2.5 (that I sold her ) behaves as if it has zero power steering for the first 10-20 seconds of running. Then it works fine and does everything it should. Never acts up while its driving.

I put 1000+ miles on the car when I had it with no issues, never had checked the level.

When she began to experience issues I checked the level for the first time in my ownership. Spot on where it should be.

Turned the wheel lock-to-lock to try to bleed the system. Level didn't drop, and the car still mis-behaves after sitting a while.

I do not know much about power steering systems. Could this be indicative of the pump going bad? Is there a check valve somewhere that is bleeding off pressure when the car is sitting?

Insights are appreciated.

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68 280SL - 70 280SL - 70 300SEL 3.5 - 72 350SL - 72 280SEL 4.5 - 72 220 - 72 220D - 73 450SL - 84 230GE - 87 200TD - 90 190E 2.0 - 03 G500

Nissan GTR - Nissan Skyline GTS25T - Toyota GTFour - Rover Mini - Toyota Land Cruiser HJ60 - Cadillac Eldorado - BMW E30 - BMW 135i

If like my 85 300D, there is a filter in the bottom of the reservoir that is easy to replace. Unlikely it would be clogged, but they are cheap. I would suck the old fluid from the reservoir first, just because good to flush it once in a while. Indeed, I think you can run the return hose into a bucket and run the engine to flush most out. Many opinions on the best fluid. I use ATF+4 just because I have it and Chrysler recommends it for all their cars now, even when replacing parts on older cars.

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1984 & 1985 CA 300D's
1964 & 65 Mopar's - Valiant, Dart, Newport
1996 & 2002 Chrysler minivans

On other cars that have rack and pinion steering, this stiff steering was caused by the Teflon sealing rings shrinking / bore getting worn on the rotary valve. A "fix" was to drill the flow control valve or use slightly thicker hydraulic oil ( like AW 46 )

I'd have to see a breakdown of the MB steering gear to look for possible sources.

The PS pump is likely OK but the flow regulator in the pump may have an issue.

I think MB uses a reaction ring / spool valve rather than a torsion bar rotary valve to sense the need for power assist but I haven't looked at the system much.

Could be belt slipping. I has the exact same issue with my 123. Tightened the belts to spec and the problem went away.


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1987 300TD
1984 300D
755,000 KM and going strong
BC Canada

Good point. The belt tensioner is problematic on the 60x motors. Check it and the spring and the pivot arm..and the belt itself.

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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

I would begin with fluid change and filter. Lift the front wheels. Disconnect the return line at the pump and turn the wheel lock to lock. You "could" bump the engine but don't let it start as it will pump the reservoir dry in a hurry. Keep the reservoir full so you don't have to bleed the system.

I buy the gallon of trans fluid at WallyWorld. A lot of fluid stays in the steering box itself which is why you have to trun the steering wheel back and forth. Check and perhaps replace the hose - especially if it is cracked on the end. Hoses are cheaper than tows.

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85SD 240K & stopped counting painted, putting bac together. 84SD 180,000. sold to a neighbor and member here but I forget his handle. The 84 is much improved from when I had it. 85TD beginning to repair to DD status. Lots of stuff to do.

Sounds like internal pressure leak, the Teflon piston seal inside the steering box can cause this but so can several other components in the system. I've resealed a few of them and its not for weekend mechanics. Also, many high mileage gearboxes are worn beyond repair in the piston bore. Careful inspection of the piston and bore is required during a reseal.