Power steering cap popped off

[Unicyclist]

Hello,
Went to check my coolant in my '92 explorer with the 4.0 v6 the other day, and noticed that the power steering fluid cap was gone. It looks like fluid was splashed around the area like it had blown off. I didn't notice any issue with the steering when I last drove it, about 2 weeks ago. I found reference to the caps blowing off in older Fords when the wheels get turned while the car is off. Does that sound like what the issue is, or was that resolved before my model year? Right now my plan is to just get a new cap and top up the fluid and see if the steering feels fine. Note: it is really cold right now, I don't know if that could have affected anything, or maybe caused the vent hole in the cap to freeze up.
Thanks!

 

[DjDom]

Just grab another cap, top of the fluid, ensure there's no air in the lines and go on with your regular routine. Sounds like it just twisted off or was knocked off from pressure.
My dad took the Ex to the shop once, and the mechanic unscrewed the cap to cause another issue so we come back..
Oh, that was great..

 

[Unicyclist]

Thanks, that's what I ended up doing. It didn't take much fluid, so I don' think it was off for long. That's a pain about your mechanic. Scummy mechanics are the worst.

 

[BrooklynBay]

My cap has a bleeder hole for releasing pressure with fluid while maneuvering into a tight parking space. I got tired of constantly refilling the reservoir so I plugged the relief hole with a screw. It was fine until I encountered a very tight parking spot. The pressure caused one side of the cap to lift up, and bend the locking tab. After doing a thorough search I realized that it's not just excessive pressure which is causing this issue.

Hot water systems in houses use an expansion tank to relieve water hammer from the circulator pump. There's a part called a water hammer arrester which is used on washing machine & ice maker supply valves to absorb the sudden surge of water flowing with an abrupt stop. I want to try using one of these parts in the return line on the power steering pump to see if this resolves this issue.