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Power steering pump?

Old 07-08-2019, 10:57 PM
Junior Member
Thread Starter
Join Date: Sep 2017
Posts: 2
Default Power steering pump?

This is the wife's car and she works from home so doesn't drive it much.
This afternoon she tells me she needs power steering fluid.
No leaks or drips under car, fluid not low, no whine from the pump as if it is low on fluid.
But to turn the wheel is something I've never felt before. It's as if there are "bumps" or rough spots as you turn the wheel. Almost like if you turned a gear where every third or forth space between the teeth were filled in. Fine once you get past the "hump or bump" till you hit the next one. Is this a bad power steering pump? I haven't been underneath to look for bent tie rods. Should I also look at the Pittman arm?
Please help. Looks like a real bear to replace the pump.
Old 07-13-2019, 09:59 AM
Senior Member
Join Date: Feb 2017
Location: Phoenix, AZ., USA
Posts: 312

Hello, and welcome to the Mercury Forums--
In order to give a proper diagnosis, we need to know the YEAR of manufacture, because early models have the "Recirculating Ball" -type steering, while the later models have the "Rack & Pinion" design.
From your description of the problem, it appears that you have the "Rack& Pinion" steering, and the problem lies with the power steering unit being "damaged".
You said that you didn't get under the car to check for suspension damage or interference that could cause the "bump" that you feel.
Also, your Marquis had non-greaseable suspension parts installed at the factory -- tie rods, ball joints, linkage, etc. -- which wear out after 45-50 thousand miles.
I replaced all suspension parts with MOOG "Problem-Solver" greaseable units.
Replacing the pump is not easy -- but it will be easier if you remove the plastic Fender Well to gain access.
While you're under there, check to see if oil is leaking around the oil pump -- if it's leaking even a little bit, replace the gasket NOW, while you have access.
Early models (like my '95) had bad machining on the engine block, and the oil pumps leaked around the gasket. I dressed the block surface before re-installing the pump and new "Fel-Pro" gasket. When installing oil pump gasket, you MUST use a torque wrench, and use NO RTV SEALER !!

When you have found and fixed your front-end problems, have your alignment done at a COMPUTER Alignment Shop that will give you a "Print-out" of your alignment before and after the alignment is completed.
Tell the technician that you want the caster, camber, and toe set at the factory NOMINALS, which are the "centers" of the specs.
Don't settle for "close enough" on the alignment specs -- a slight error on the TOE setting can eat up your expensive tires pretty quickly.
I got EXCELLENT wheel alignment at a local GOODYEAR Service Center that has a brand-new BEAR Alignment Rack.
After a proper alignment, the 24-year-old Marquis handles and steers much better than when brand new.
Lemme know what you find out, as I'm curious !!
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