Blowing out power steering fluid

[EB]

I've been having a problem for a while with my truck blowing off the power steering cap and losing fluid. It got to the point where I had to go "out of service", which means basically that I can't work until I get it fixed. I cked all the lines and found them to be clear, no obstructions, and the cooler seems to be clear. I disconnected my Milemarker winch so the fluid was just by-passing in case that might be the cause, it didn't matter. The only thing I noticed while cking this was that the cooling fan clutch wasn't working, I also have the 0483 code, I can stop it from turning with my hand when the engine is at operating temp. The only time the cap gets blown off is during a long haul, I wouldn't think this time of year the power steering fluid would get hot enough to cause a problem, but it is the only thing I can come up with. I pull a trailer with fairly heavy loads in my work. Anyone have any other ideas?

 

[rbattelle]

The only thing I noticed while cking this was that the cooling fan clutch wasn't working, I also have the 0483 code, I can stop it from turning with my hand when the engine is at operating temp.

You are a braver man than I!! In my opinion, P0483 indicates you've either got a bad fan clutch or bad wiring. The PDM suggests checking the following:



1. Measure the resistance between the signal circuit in the fan clutch assembly and the battery supply circuit in the fan clutch assembly. It must be less than 10 ohms. If it's not, the clutch is bad.



2. Measure the resistance between the ECM harness connector and the fan clutch assembly harness connector. It must be less than 10 ohms. If not, repair the wiring.



3. Measure the reisistance of the supply circuit between the ECM harness connector and the fan clutch assembly harness connector. It must be less than 10 ohms. If not, repair the wiring.



4. Measure the resistance betweent he signal circuit in the fan clutch assembly harness connector and the return circuit in the fan clutch assembly harness connector. Resistance must be less than 10 ohms. If not, repair the wiring.



5. Measure the voltage between the signal circuit in the fan clutch assembly harness connector and the battery negative. It must be greater than 1 volt.



6. Measure the resistance between the signal circuit in the fan clutch assembly harness connector and battery negative. It must be less than 10 ohms.



As for the power steering pump, I think I recall someone else having a similar problem with the pump puking fluid out all over. I think they had a bad pump (seal). Service manual doesn't offer any help.



I hope that helps a bit...



-Ryan

 

[tkerrigan]

Could the power steering pump have a leak on the suction side of the pump, therefore sucking enough air on long trips to pressurize the cap?

 

[rbattelle]

Could the power steering pump have a leak on the suction side of the pump, therefore sucking enough air on long trips to pressurize the cap?

An interesting theory, but in my opinion the power steering pump is a very poor air pump and hence wouldn't be capable of developing any significant air pressure under the cap. Just a theory.



One other possibility - could the PS fluid be foaming? EB, what type of fluid are you using in it?



-Ryan

 

[EB]

Using Amsoil universal fluid, does't show any foam. Had the pump replaced about 6 months ago, and they used the Mopar fluid, since then every time it blows out I bring it back to full with the Amsoil, I'm sure it is almost pure Amsoil by now. I still believe the fan clutch is the problem, will find out Monday when it is replaced.

 

[tkerrigan]

Back to suction side air leak, think of very small air bubbles entrained in the oil as it is pumped. These air bubbles will go through the power steering gear under compression. This pressure is released under the cap. When the cap pops off, under pressure, air bubbles still in the oil will push it out. If the suction leak was just under the pump, there could be little, if any oil leaking to the exterior.

 

[EB]

I washed everything off real good this morning, don't show any leaks on the return or suction side. You wouldn't think that that O-ring would hold enough pressure to cause the cap to pop off. I have been thinking and really still think there is an obstruction somewhere that I can't find, like the hydro- boost. I'm not going to fool with that, but if the fan clutch doesn't cure it, I will replace it. I have to work and can't with an oil leak.

 

[EB]

I took my truck in this morning, explained the problem and after about 5 hrs back and forth with technical service in Detroit, no one here had ever heard of anything like this, it turns out there have been four trucks nation wide with this exact problem. Technical service said to change the rack and pinion, it fixed the other four. We got one on order, hopefully it will be here tomorrow and we will find out if that corrects the problem. The rack and pinion is $587, I sure hope it corrects it.

 

[TexBamBam]

My power stearing fluid is leaking out too... but the cap is not blowing off... just running out of the bottom.

 

[rbattelle]

EB,



You do have a 2wd, right?



On Edit: yes, you do... checked your gallery.



-Ryan

 

[JLehman]

Yeh, just put half a quart in my power steering pump yesterday. No sign of a leak anywhere, maybe just low from the factory?? It was doing some howling was why i checked.

 

[EB]

I guess the experts were right, I just finished a 750 mile round trip run with no problems. I knew there had to be an obstruction someplace in the system. I guess it would take a while to build up enough back pressure from the rack and pinion before it would blow back and knock the power steering reservoir cap off. Unless it messes up again, I'm going to consider the problem taken care of. I sure hope so, $912. 57 total cost. They also had to do a front end alignment when they changed the rack and pinion. I was also informed that my top ball joints were about gone. I sure hope this truck isn't going to start falling apart on me. Things that I know that are going to need to be repaired pretty soon are; upper ball joints , fan clutch (for the second time) and ring and pinion gear. It is starting to get kind of expensive for a 2 yr old truck. Needless to say, I'm out of warranty.