Radiator Cap Stuck

[MikeP]

My radiator cap appears to have gotten cross-threaded and is stuck (not able to remove it and difficult to lock it in place). Any hints on how to remove the cap? One approach is to break it and replace it with a new one.
1991 Explorer with about 220,000 miles. Got it new in July 1990.
Mike

 

[Tony H]

Are you pushing down hard as you turn it?

 

[mikeinri]

If you try to break it (or cut it somehow), just be very careful, as it is screwed into the plastic housing of the radiator. If you damage that, you have to replace the whole radiator.

If you could somehow get to the "teeth" of the cap, you may be able to bend them enough to free it up. Again, be very careful if you're prying against the radiator neck (plastic).

Mike

 

[410Fortune]

there are no threads on your rad cap, it is a simple push and turn like asprin, try again it should not be stuck

 

[marragtop]

Agreed, it's not threaded. Push down with the palm of your hand and turn at the same time. You need to lean some body weight into it with straight down force.

 

[BrooklynBay]

Don't open it when the engine is hot.

 

[JIGAWHAAT]

Give mental a call. He will come over with his hammer

 

[MikeP]

Unstuck Radiator Cap

Thanks for the advice.
The cap is not actually threaded but it has those two locking tabs that sort of act like partial threads.
I think I got the cap "tilted" when I tried to replace it after checking the radiator fluid level and those two locking tabs were not located properly (the cap was "tilted"). It would only rotate about 60 degrees and pressing down it just would not release it.
I started up my engine and let it warm up about 5 minutes (it was freezing temp on Friday morning). Then I shut the engine off. The radiator had warmed some. I was able to rotate the radiator cap and remove it and install it correctly. I am guessing that the warming of the cap expanded the cap sufficiently to enable it to be removed. Yes, the message here is to be careful when replacing the radiator cap because it might not seal properly. There is some writing on the cap, something about lining up the arrows with the drain tube, etc. which implies that it must be possible to not replace that radiator cap propertly.

I have removed that radiator cap lots of times. The "cheap" plastic parts on the Ford Explorer radiator will develop leaks and so I check the fluid level frequently. I have never gotten around to replacing this defective radiator with a "real" metal radiator.

By the way, sometimes I drive out in the "boondocks" a considerable distance from anything and I like to be able to repair something that might go haywire. I have had stuff go hayire with my Ford, but luckily only once while I was out in the "boondocks" and that was a battery wire came loose after driving on the rough roads and I was able to find and fix it (not the battery cables but one of those other wires). In my former GMC 3/4 ton 4x4 I used to carry a number of spare parts so I could fix stuff like a broken radiator hose, fan belt, 2 spare wheels, etc. and it helped alot. My Ford Explorer is not nearly as tough as that GMC but it has survived about 17 years now which is not bad.
Mike