Hi, My 4wd Dakota with 50 K on it had a horrible pump whine a year ago and the fluid was black so I had a local shop replace it and it cured the whine but then started leaking, probably because he replaced the pump not the reservoir. A friend just opened his own shop after years at a Chrysler/ Dodge dealer and he replaced it again with a complete(new) pump. Again the fluid was awful. He removed the rack , replaced the seals and flushed it. Put it back together and now it whines worse than ever. Drives fine all along. where are we missing the point? Thanks, audio tach man.

 

Need to replace pump and rack together. The whine is from worn vanes in the P-series pump leaking fluid past them, instead of sealing to the outer casing of the pressure volute. This lack of seal is from cheap castings, poor machining, and/or trash being in the volute. Thinner, clean fluid will make the whining more prevalent since it can slip through a thinner vane gap. The noise can also come from the pump running dry, allowing metal-on-metal contact between the vanes and the volute.

The P-series pump also uses a bronze bushing to seal the front shaft, which is prone to leaking when the shaft or bushing have worn down. Remanned P pumps just replace this front bushing and put new vanes in, and that's it.

 

My original post wasn't very clear. in the last evolution the fluid was again black and leaking between the reservoir and pump, but it was quiet. My friend replaced the pump with a complete OEM pump and reservoir, removed, flushed and re-sealed the rack, and refilled and bled the system with the correct spec'd fluid. We all know that just because it is new it doesn't mean it is good, but after all that expense I hate to think the pump is just poorly machined. I am sort of resigned, but it is really annoying. mcdust

 

Putting it nicely, the P series pump is a piece of manure. It was designed 30-odd years ago (or maybe even 40) and I don't know that new castings are even made for it.

The TC/Type 2 pump is a much smaller, more efficient pump, but it does not exactly fit in-place of the P series because of the size difference. P pumps mounted various ways from different manufacturers while the TC/T2 pumps have exactly 2 mounting methods on a single bolt pattern.

I could probably sit down and make a bolt-on conversion setup, but I don't have that kind of time or money.

 

Thanks for the explanation. Sadly it sounds about right. Mcdust

 

The fluid will always turn black fast in just about any PS system. I replaced mine with ATF+4 many years ago (any ATF will work). Still have a low level whine, but I've gotten used to it.

 

magnethead

Is the pump on my 2.5 the same?
Never noticed it whine much but I dont have a big heavy Dakota or big tires never noticed black fluid either been using Royal Purple synthetic for 3 years it does have an external tank not like the other engines. I also installed a fluid filter 2 years ago plus the hoses hold a large amount of fluid in them. That tank holds a lot of fluid also.

Because I have an external tank I could install a fluid cooler.

 

A whine with everything new would make me suspect there is still air in the system. Bleeding is a notoriously tedious process on the p/s system......

 

The Jeep 2.5 and 4.0 use the newer style TC/Type 2 pump, as do most any engine designed newer than 04/05 or so.

 

Thanks gentlemen, 98dakaz; my tank is integral. / Dodgevity; I am running +4. I've done most of my own work for 50 years and never seen steering fluid black like this. / HeyYou; I did a lot of lock to lock when I first got it back, but now I see another bleed process, I'm going to give it a try. Nothing to lose eh? Mcdust