My power steering pump MB A-Class type is overloading and shutting down on full lock. It is a fail safe of sort where the pump slows down significantly on full lock (left and right) and then stops. Disconnecting and connecting the trigger wire restarts the pump.

Quick story: I have redone all my suspension, every bushing, ball-joint, steering linkage, spring plates, struts, springs, strut mounts, etc. With that I have refreshed steering my rack (all new seals) and Elephant Racing bump steer kit and elephant inner tie rods. A while ago I have upgraded to MB A class Power steering pump (no issues for a year, then the pump failed and so I replaced it just recently. Same wiring, same plumbing, same everything, just working pump.

Clue 1: The elephant kit is designed as such that allows for greater steering angle. To the point that before I reach the lock the tire will touch the inner fender.
Clue 2: The OE setup requires the steering stop to be installed (blue picture). The stop has dual function it aligns the bushing and provides the stop. The Elephant setup doesn't require the stop for bushing alignment since it is a ball. Because of that it allows the rod to slide deeper in to the steering rack tube. I haven't installed the stop.



Question 1: Since the steering angle lock is reached not with a mechanical lock (OE washer) but with the tire rubbing on the inner fender, does that can be enough to overload the pump?
Question 2: The rack directs the pressurized fluid in one of 3 ways: left chamber, right chamber and loop back to the reservoir. When reaching the lock (fluid directed to right chamber for example) does the rotary valve resets in any way to direct the fluid back to the reservoir or it just maxes out and builds up the pressure in hopes the pump pressure valve will open?

I'm hoping to narrow down the issue, is it the pump? Maybe the steering rack?
Hopefully there is an power steering guru here that will educate me on the topic.

Thanks!
Andrew

 

Hi Andrew, are you suggesting that the rack is now sweeping in both directions to limits that are greater than they were originally? If so, that could be the problem. Without detailed knowledge of the inside of the rack it could be that various return paths are becoming fully/partially obscured with this extended travel.

 

Yes, it seems that using mechanical steering locks is necessary. I will put them back in, probably even the extended OEM ones for when I will go 18inch wheels in the future. Regardless, I still don't quite understand the torsion bar passage alignment under force and lock.

Thanks!
Andrew

 

in run the elefant bump steer tie rods and i just used the oem steering stops.. no problems at all