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POWER STEERING PUMPS

PostPosted: Sat Feb 23, 2019 11:03 am
by BillyCorgi
POWER STEERING PUMPS
So here is a story of "lessons learned" from the book of product knowledge.

We had a customer raise a concern with us that his exchange PS Pump was losing power assist. He had had the exchange pump fitted by his mechanic and I have no idea what transpired with the install. He brought his car arround for me to have a look at and yes, indeed, the power assist was experiencing drop outs. The customer is always right. Another PS Pump was prepared for him and arrangement were made for him to come back and have the swap-over unit fitted.

The follwing weekend the second PS Pump was fitted and on test drive it was displaying EXACTLY the same symptom - The power assist was dropping out.
WTF - FMD.

Many hours transpired trying to diagnose the issue. Too many hours. Two pumps in a row with the same issue. Statistically, there was something else in play here. Searching for data the rear cover of the first PS Pump was removed and the internals of the pump were showing damage with signs of the PS Pump being run dry. Whale Oil Beef Hooked! Why?

With nothing left to lose, the fluid reservior, hidden under one of those JDM covers, was removed and we believe we found a clogged strainer in the reservior. That would cause a fluid restriction? The fluid was drained and the inards of the reservior back flushed by blasting with a garden hose. The reservior was dried as best we could and flushed with Methylated Spirt (alcohol) to disolve the remains of any water.

A second hand PS Pump was fitted and everything was reassembled and then another flush of the PS system to ensure no remanaants of metal particles remained to do damage. It worked! Drop outs gone.

It only took about 12 hours!

Lessons?
(1) the Showa brand of PS Pump fitted to WRX and Liberty GT Turbo cars seems to be a bad "primer", not good at sucking,and more susceptible to restrictions on the pump inlet side.
(2) When servicing your PS Pump system, even just doing a flush, ensure that the fluid reservior is also inspected. A nice good flush may just help to dislodge the muck and scum in the fluid system and allow it to start to migrate to the filter screen in the reservior and cause expensive failures.

More Lessons?
In the last week or so we were contacted by a Subaru owner looking for a replacement PS Pump for his WRX. Apparently his PS pump had "seized" after a very recent fluid "flush". We helped diagnose the problem and helped confirm that there was no saving the pump. The new fluid was full of "sparkley bits" - shiney pieces of metal ground out of the PS Pump when it ran dry due to what we believe was a blocked strainer in the reservior.

CorgiWerx - The Subaru Centre Differential Subject Matter Experts

Re: POWER STEERING PUMPS

PostPosted: Mon Feb 25, 2019 9:17 am
by fedaykin
He had had the exchange pump fitted by his mechanic and I have no idea what transpired with the install.

So another case of "mechanic" not flushing the system properly.

Re: POWER STEERING PUMPS

PostPosted: Wed Feb 27, 2019 9:09 pm
by spike2135
Thanks for the great info!! :good: