GizmoJoe

This has been happening for a while but it's been too cold outside to look into so the truck hasn't been driven much for most of the winter. I was hoping to start it up today and the this went away thinking that it might have been cold related...guess I am not that lucky.

Whenever I turn the steering wheel I get a fairly loud hum that sounds like it is coming from the engine compartment. I also get the same sounding hum whenever I press the brake. Not sure if these are related or if these are 2 different issues.

Any suggestions appreciated

johnh

the brakes are assisted with hydraulic pressure from the power steering pump......... that should answer your question

cody_d

refill your power steering fluid. check around for your leak, when it warms up.

nickg

replace the PS fluid with a synthetic oil, and the noise will go away,

mstep3

I had the same issue with mine. I replaced my PS fluid with Royal Purple synthetic ps fluid. It works great now. No more growl on cold mornings. Your old fluid needs to be flushed out though. I think it breaks down over time.

Junk Man

My power steering pump with synthetic fluid, filled to specs is making noise also. I think it's from running it dry when the AGR steering box took a dump.

bobem12

Try some lucas oil power steering stop leak. It really did the trick on my truck. It was doing exactly what you said.

GizmoJoe

Thanks for all the suggestions. I never did realize that the brakes are assisted through the power steering pump. I also did forget to mention that I also have a power steering fluid leak. I have been using the lucas to top off the fluid in the past and used about 1 1/2 bottles ofer the last 2 years.

I finally got back out there today with my $3.00 engine stethoscope (one of those things I bought because it was cheap for the just-incase and finally used it for the first time) and the sound is definately coming from the power steering pump, which is also where I think the leak is from even though I haven't been able to locate it in a year of looking.

Napa has one for $109 so I am on my way to go pick it up. Hopefully this will take care of my issue. now it it time to search the forum here to find out the tricks for replacing it.

GizmoJoe

OK...I am glad that I did more research before going out to buy a new pump. I see that some people have changed the pump and still had the same problem.

So I figured that I would go and try the synthetic route first to see if that would take care of the whine.

Since I was already on the jack I did the turn the steering wheel back and forth thing with the engine running to bleed the lines (I did it earlier but I didn't have it running). Shut it off and went back under the hood. After about a minute I hear this hissing sound. I had the power steering fluid coming out from under the cap (at least I know where my leak is now). When the hissing stopped, I opened the cap and it was filled with suds. I am waiting right now for them to go away and do it again to try bleeding the lines. I'm going to try sudsing it up again in a few minutes and run out for synthetic PS fluid.

I also read that there is a screen inside the power steering pump. Can someone point me in a direction on where that is so I can clean it?

nickg

Your Hydroboost is at fault, Whats happening is the acculimator in the hydroboost is dumping its extra fulid back to the power steering reservoir, MOST times replacing the fluid with synthetic oil, helps eleminate the overflowing reservoir, but usually this only helps in COLD weather.
In your case if its warm out and its dumping fluid back the hydroboost is at fault. you can comfirm it if you run the truck up, shut it off wait a while then step on the brakes, you should have 1 or two assisted brake applications, if the pedal is rock hard (with eng off) the hydroboost requires rebuild or replacement.

messing with the pump is not going to help with your problem

GizmoJoe

It took a while to find synthetic PS fluid and at my 5th auto parts store I finally found Valvoline synthetic fluid.

Sucked all the fluid out of the pump which was easy with the fluid extractor that I have for changing the oil in the boat. Cleaned the screen which didn't look that bad. Filled it up and did the 20 turns stop to stop and pressed the brake 20 times...the whining came back. Repeated sucking out, filling up, turning and braking 2 more times...everything finally sounded and felt good.

I just got back from a 30 mile backroad and highway test drive. I am suprised at how well the steering was. It used to float on the highway but it doesn't float anymore. When I was going down the hill near the house I hit the brakes hard for the first time and I thought I was going to go through the windshield when prior to the fluid change they were marginal at best and I thought I was going to have to do another brake job before boating season.

Nick, I went out after seeing your post and 15 minutes after parking it I still had 2 assisted brake applications before it went hard.

Supposed to be cold again tonight so I'll test it out in the morning and keep you posted...

Thanks again to all the DTR people for getting me pointed in the right direction.