So, I picked up a 99’ Ranger XLT 4wd & it has a very noisy power steering pump. Truck has 81,000 miles. Does anybody have a idea on how to quiet its pump?

 

No replies yet so will see if I can get things started. Is this a flood or salvaged vehicle??? What type of noise, was it there at the time of purchase, or has it come about suddenly after some event???
Is it present all the time, or only when turning??? Might be helpful if you'd use your phone or the like to post a audio recording, so the Forum ears can hear what your hearing.

Are you certain its the pump & not the serpentine belt, its tensioner or idler pully bearings???

Check fluid level & condition. Top up if need be with the specified fluid. If the fluid is / was low, it can become aerated & that can make the system noisy. We can speed-up the de-airing by applying a vacuum to the pump cap reservoir vent hole with a needle attached to a vacuum source like a mighty-vac, syringe, vacuum line to the engine, or a vacuum pump if you have one, but add a filter to the engine or vacuum pump line, so as not to contaminate them internally with deairing vapor mist.

Some initial thoughts for consideration, let us know what you find.

 

Check your belt and pully also. Some Rangers and Broncos have a crying pump even when you can turn the wheel with one finger. Maybe try a stop leak that also repairs stiff seals and see if it makes a difference .

 

The sound is the typical whine. Father in law bought the truck in 2001 & it has sounded this way since the day he brought it home. I’m thinking about trying synthetic tranny fluid to see if that helps

 

Ok, sounds like the usual Ford P/S noise anomaly. Long story but results may fit so bear with me. Our 94 Taurus had slowly developed a louder pump whine, that a system fluid exchange didn't affect. Later it suddenly developed recurring boost drop-outs that came & went. As it was time for another fluid pump-out, (I do them with a tranny filter change & fluid pump-out every 30-35 K miles), so those fluids hadn't become degraded. Thus I decided to try a system tidy-up, so removed the P/S pump return line at the cooler to drain the pump reservoir of old fluid & any deposits (none noticed), then reconnected the return line to the cooler, added half a can of Seafoam Trans Tune & new tranny fluid to back fill the pump reservoir to the cold fill line.

Drove it for 3-4 days until boost drop-out stopped, then disconnected the return line at the cooler to drain the pump reservoir again. Plugged the return line with a round shaft screwdriver & added the other half can of Trans Tune & more new fluid to top up the pump reservoir.

Added a section of hose to the disconnected P/S cooler output fitting, the other end in my catch bucket.

Disconnected the inertia switch connector to disable the fuel pump so the engine wouldn't run.

Opened a couple of qts of new fluid, so they were ready to use.

Raised the front wheels to clear the ground, so my helper could turn them lock to lock while cranking the engine & I tried to keep the reservoir fluid topped up, so it wouldn't become aerated, as the old fluid, deposits & Trans Tune were pumped out of the pump, rack, return lines to the radiator & aux cooler, so as much old fluid, Trans Tune tidy-upper & deposits could be removed & as much new fluid as possible could be put in.

Then added a Magnefine inline filter at the P/S cooler output, removed the screwdriver plug & reconnected the pump return line to the other end of the Magnefine filter. Topped up the pump reservoir again & repeat the flush every 30-35 K miles.

This has stopped the recurring boost drop-out problem & as a side benefit, the P/S pump became whisper quiet & remains so after about 15 years!!!

The 99 Ranger in my signature developed the same boost drop-out problem as the Taurus, so it too got a Trans-Tune flush & Magnefine filter in its return line & hasn't had any boost drop-out in about 13 years. The Ranger never developed a noisy P/S pump & its remained quiet so far.

If the system develops a leak & fluid gets low & aerated, the pump can become noisy.

A bunch more thoughts for consideration, let us know what you find, do & how it goes.

 

BUMP:
Well Jamey, how is the power steering pump whine trouble shoot going, 267 curious minds would like to know???

 

So far it’s still whining. I vac’d out the old fluid & tried synthetic tranny fluid instead, but it’s still whining. However, it doesn’t get any louder when you cut the wheel

 

Ok, good feedback, So as I interpret what was done, you now have a mix of old & new fluid in the system, as it reads like you just sucked out old fluid & refilled the pump reservoir with a higher refined quality base fluid, so the pump, lines, rack & cooler if equipped, didn't get flushed with new fluid??? If so & you've seen some noise abatement when you turn the steering wheel, then a complete fluid flush & adding a quality inline filter, like a Magnefine are still on the consideration list, so would be interesting to hear how they work out if tried.

 

Will do & report back 👍🏻

 

Since the original post on this was about six months ago, I realize I'm a little late in the game. The OP has lived with it awhile and, like a bratty child, has probably learned to ignore it or just tuned it out, so to speak.
That being said, as a few people know, Ford power steering pumps of this era were quite noisy by reputation. The noise can be quieted, but sometimes the fix can cost more than what an owner wants to pay.
First off, if you buy your REMANUFACTURED pump from a national chain store, you got it on a price-point and you will have a noisy power steering pump. You can spot these pumps when your counter sales(wo)man tell you the price and includes the phrase "lowest price guaranteed". If you replace your power steering pump and heard that phrase when you purchased it, odds are you will have a noisy pump. Browsing through the RockAuto listings for your application, there are some cheapies listed that are questionable when it comes to quality.
If you want to get rid of the noise, I'd recommend a completely new pump or a genuine Ford reman. You also want to use the best fluid available, vacuum purge the air and leave it set overnight before using it to let the foam return to liquid. Ford used to put a little pamphlet with their reman pumps on why the aftermarket pumps were noisy and theirs were quiet. I wished I'd saved one, but it's not the case. There are also some decent completely new pumps available. They are considerably higher.
Magic pour-in elixers to quiet noisy pumps exist and some people have had results by using them, but it's hit-and-miss. Good luck with your noise.