Still hope someone can tell me what caused this mystery.
It was around 5 degrees for several days.
My truck set for a week. It is a 2007 F350 crew. The other day the temp rose to 47 degrees during the day. Around 6:00 eve there was PS fluid leaking out on the driveway small pool. Then after 1 hr., the pool was around 2 ft in size.
I looked into the tank and it was full running over the side of the cap and the other fluid had squirted out of the little vent hole on the cap and on to my battery also.
I started up the engine and the wheel would not budge or turn at all. Locked up.
It snowed again and then two days later I again looked at the cap and still full to the brim. It had warmed to 45 degrees and sun out. I again started the engine and still no power to turn the wheel. I tried to force it and no luck. I then rived up the engine to around 2800 rpm and all of sudden something gave way and the wheel started to turn again. I worked the steering wheel back and forth and it
did turn as usual.
I looked at the PS cap and the tank now was empty. All of the fluid had went down somewhere to the bottom of the tank. I refilled the tank with 1/2 qt of PS fluid and after running the engine again it is as nothing ever had happened. No more leaking on the ground and the wheel turns fine.
Anyone know what could have caused this mystery? I might also mention that I have never added any PS fluid to the system before this problem.
Thanks for reading.

 

My experience with my gasser MIGHT be relevant. I was experiencing symptoms somewhat similar to you and discovered that a nut on one of the lines was a bit loose. The leaking fluid was actually pretty difficult to see - well, except on the driveway, where the puddles were!\.....

So anyway, tightened up the loose nuts, fluid re-filled, and problem solved!

 

From sitting, the system could have developed an air pocket or it may have had some moisture in it causing the fluid to thicken or even debris in the system from sitting. A pressure relief valve is used to keep the pressurized hydraulic fluid at the desired levels and this could have been stuck as well.

It's anybody's guess but i wouldn't worry too much about it if it's working fine now. I would do a full system flush though. Make sure you follow the proper techniques on doing that or have a shop do it.

 

Thanks for the information. I know it is not a leak caused by a loose fitting or nut. It did come out of the top or the cap thu the vent hole on the cap. I can see where it sqirited to the hood and on down on the battery. It is some kind of pressure that built up inside the system to push 1/2 quart of fluid out and onto the ground.

 

I would say what some of the other have said.
You either froze or the vavle went goofy.

Dad's 06 has blown the return hose 4 times in almost the same exact spot each time.
This was in weather ranging from 32f to -40F.
Been holding since i took out the cooler.
Fluid has been flushed every time when it blew.
But we do not do any extended driving up here.

 

I'm going to mention again the loose fitting because it offers an explanation of the problem, and checking a few nuts is so trivial an effort.


The power steering is a closed system. The pump pressurizes the fluid on one side, and accepts less pressurized fluid on the other. If the less pressurized side has a leak, it will suck air into the system, and quite possibly pressurize it in the process of pressurizing the high pressure side. I would think at some point this could maybe cause your "vomiting" problem.

 

In the four years I had the truck, no leaks, no adding of fluid, No leaks anywhere on the engine area on PS hose or nuts. Still no leaks now after this mystery of the flluid coming out the top vent hole on the cap.
It had to have some kind of pressure when the temp rose from 12 degrees setting there for 4 days and then the temp went above freezing that day. I agree that some kind of check valve etc broke loose when I ran the engine up high RPM and the fluid that was up to the filler cap edge just dove down into the bottom of the tank and thus I was able to put 1/2 quart of ps fluid back into the tank to the fill level.
Does any one have any drawing etc of the PS system. If so this could clear up just
what went on during that freeze up and thaw.
Thanks

 

This problem seems to be temperature related. A "plug" when is is very cold out and OK when warm.

My guess is that some water made it into the PS system and froze when temperatures dropped. The water will seek a low spot in the system when the truck is off (water is heavier than oil). Once frozen, it could cause the locked-up condition that you saw.

Getting the water out would require flushing the fluid out or draining from a low point.

Lou Braun