When I was going through the engine compartment of the recently acquired 7.3 yesterday, I noticed the power steering pump cap was not on properly and only had one of the two tabs locked. I pulled it off and discovered that the o ring seal was broken.....so I went to advance and found an o ring that fit properly and replaced it. Noticed that the PS fluid was very dark and discolored. When I would start it up whenever I turned the wheel it made a weird noise, not a whine but more of a low pitched sound. Then it went away. Figured I needed to address it asap.

I had the power steering system flushed today through the pump at a local fluid change company with Mercon V before any further damage could be done and they told me the extracted fluid had water in it because some of the fluid was a light pink. As well as very dirty. I bet that the loose cap let all sorts of dirt and water in. The rest of thefluids looked good.

I have no issues with steering or brakes, but there is now a slight hum at times now that I did not notice before. Mainly at low rpms. Brakes are actually better now than they were before. The more I drive it the less it seems to hum.

Eventually am going to flush near the booster and put in a magna filter and synthetic but I couldnt leave it the way it was.

Should I be concerned with the low, intermittent "hum" at times or is that just air that needs to be worked out of the system over the next few days?

 

My guess is it wasn't the air was not completely bleed out of the system. remove the cap, shine a flash light down in the reserviour and check the fluid being returned. If it is frothy or bubbly then your pump is cavitating and the system needs to be bleed. Cavitation will kill your pump.

 

Was frothy earlier, not as bad after driving around.


in the am tomorrow before I leave for work should I turn the wheel "lock to lock " and push the brake pedal to help bleed the system quicker?

 

Lift the vehicle off the ground with key on engine off and turn the tires lock to lock a few times. This should help bleed the system.

 

Will do. Is there a good jack point under the front end I should use?

 

Do you have a 4x4? I used two floor jacks on the tube of the axles for mine. Other wise under the spring perches worked OK too.

 

No its a 2WD. Can I jack from the crash bar just to bleed the ps psystem?

 

Do you have the OEM book in glove box? It should have some jacking points to use. I have never looked under a 2wd, can't help much there.

 

Went out and jacked up front end and with key on/engine off did about 10 cycles lock to lock. Early on burped a little fluid out onto the frame / underneath but a little brake kleener cleaned it up. Topped ps pump off with mercon V. Will see in the morning whether it worked......

 

If it is still cavitating then jack it back up and do it again.

This time time do 20 or 30 turns lock to lock and then let it sit for 10 or 15 minutes and repeat. After 2 or 3 cycles of doing that with the wheels still off the ground do it again with the motor running but avoid turning all the way to the stops where the bypass valve open ( you will here it ... Avoid that ) Do 3 cycles of 20 turns with the motor running.

FYI.... The reason you let it sit for 10 minutes or so between cycles is to let the air bubbles in the oil to dissipate.

If after that process it still persist then drain the fluid and start over. Total PITA but it isn't unheard of.

 

Worked perfectly. No more humming. Thank you!!

 

Bleeding ps systems Can be stubborn. .. You just have to keep escalating the effort until your foe succumbs to your will.