Radiator cap - how do I get it off?

[jazrotorman]

Hi,

I have a mk7 2012 Fiesta Zetec manual and am having trouble getting the coolant cap off.

I know there are issues with some people on the forum saying they can get the cap off but it leaves some of it in the coolant reservoir, but my issue is that I can't actually get it off at all. When I turn it anti clockwise, I can feel it releasing pressure from the thread but then as I keep turning it in the same direction it starts tightening again.

Is there some trick to it?

Hoping not to have to replace the cap as a non genuine one is $76nzd (40 pounds!) at our local Repco parts centre.

Water line is just below min too so I better get it filled (I suspect that when I have been taking it in for it's oil change, they havent been topping up the water as they can't get it off!

 

Thanks

[Radu Nastasa]

Hi,

I have the same problem. I am curious how you managed to remove the cap?

Thank you

[unofix]

This should get it off. You might need to think about a new expansion tank afterwards 🤣

[Ian500]

Hi  Radu     There are many posts on this topic, see below is one.   Rad Caps are on eBay (UK) for about £6.50 !!            Hope this helps.

https://www.fordownersclub.com/forums/topic/98627-coolant-reservoir-cap-stuck/#comment-703253  

 

[isetta]

When mine was stuck I drove it to get the engine hotter to create sum pressure in the coolant to help push the cap upwards. You need to be very careful if you do it this way, you could get scalded by steam and boiling water and lose a load of coolant that needs replacing.  BE CAREFUL****.VERY CAREFUL

[Radu Nastasa]

Thank you for the replays!

I managed to remove the cap by hand after following one of the solutions from this post:

With the engine cold, I first loosened the cap as much as possible(almost one turn). Then I let it sit in that position for one minute. The I tried to loosen it some more(almost a quarter of a turn). I repeated this step again after one minute untill I made 2 complete turns. Then it started to loosen after each try.

I spent quite some time waiting but eventually it came off in one piece.

I replaced only the cap because I had a new one. As others suggested, I added some silicone grease on the two orings to prevent it from getting stuck.   

The tank has some fine cracks around the base of the cap but seems to hold presure and I am not loosing coolant so I am not sure if it needs replacing. I will post an image tomorrow.

[Radu Nastasa]

Happy new year!

Today I made a photo to highlight the radiator expansion tank fine cracks. I do not know when they appeared. Maybe someone forced the radiator cap before me or it's a normal wear of a 5 year old tank.

Does any one know if the tank should be replaced or is this a normal wear that appears in time?

Thank you!