Recently took a 1600 mile r/t in my '04 DII SE7. The truck has 125k on it. On the trip back when I made the first fuel stop the power steering was groaning and not working. I popped the hood and the reservoir was full. Since it was not an issue at highway speeds I continued and it was the same at each stop - no power steering, groaning pump, reservoir full. Got home late, parked the truck, next morning a puddle under the truck and the front half of the reservoir was empty (rear full). I had to drive it for a meeting that am so I filled it back up and drove it. After a couple miles the noise stopped and the power steering felt more or less normal. Parked it - no fluid under the truck, reservoir low but even across both sides. Topped it up and no leaks or loss since. It has been a week now and no recurrence of the issue.

My question is, what could have caused this and what should I do to prevent it from happening again.

 

The rear part of the resevouir is for the ACE system.
Why did the system go empty? Because you have a leak.
Check the hoses and the steering pump and box for leaks.

 

Park it
Find leak
Fix leak
Carry on after its fixed and never look back

 

That is the perplexing part - the system failed with a full reservoir, then drained overnight obviously through a leak, yet when the system was refilled the system worked normally and there was no further leakage.

I am carrying on and thanking my lucky stars (so far) that I don't have to replace the pump, but "self-sealing" leaks and unexplained failures always leave me seeking advice in the event someone has run into this before.

 

Somewhere it leaked so if you investigate enough you will find the source. Don't count on it fixing itself because when you are in mid turn and think you have it and it fails you may kill yourself or someone else. You will never forgive your self if you wipe out a bus stop full of kids because you thought a magical ferry fixed your pump/leaky hose or whatever it is.

 

It was probably sucking air through the leak and thats why the pump was groaning and it all leaked out when you parked it.
Keep a eye on it.

 

[QUOTE=Spike555;349304]It was probably sucking air through the leak and thats why the pump was groaning and it all leaked out when you parked it.
Keep a eye on it.[/QUOTE


Yes but wherever it was leaking from should still have a trace of wetness and you should be able to locate it.

 

Just start the engine and crank the wheel left or right to "lock" (until you cant turn anymore) and hold it there while someone inspects the lines. Let off every few seconds and hold it at lock again. Repeat as necessary. I'm sure you'll have no problem finding the leak.

 

I thought that might be the case since the reservoir was full and yet the pump was groaning as if it did not have sufficient fluid.

The new fluid included a stop leak and and I guess it is possible the leak was small enough that the chemical sealed it. I inspected the lines during the trip back and when I got home and I could not find any leak, and it wasn't until the next morning that any leakage was apparent.

I check the reservoir before every trip and park with cardboard underneath in the garage to check for leaks. I'll go over the lines again and see if I can see where the leak might have been. Going through the maintenance records the lines appear to be original, so it may be that replacement is the best option.

Thanks!

 

Your welcome buddy, good luck on your fix and just think safety first.