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MJNewton

Tight expansion bottle cap

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Has anyone found there expansion bottle cap to be tight, I mean *really* tight? First time I noticed it I just about got it undone with my hands but I was very close to resort to tools. Since then I've had to give it a lot of grunt again to the extent that today the cap came off in my hands but the pressure-sealing body remained in the tank!

I got the body out with adjustable pliers but I can see this happening again if I don't do something about it. It seems a widely available part, copies of which are also produced by many other manufacturers, and so it made me wonder given such availability whether they are a regularly needed item so thought I'd ask here. (Edit: I've seen an application list and there are hundreds of Fords and Volvos on it so perhaps that's why there's such a market for them!)

I am assuming it's the cap (and not the bottle) at fault and that perhaps one of the o-rings has swollen somewhat hence why it is remaining so tightly wedged in? There were no other obvious indications as to what it might be.

ecoboostexpansionbottlecap.jpg

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mine did the same thing I ended up cuting the centre part out with a red hot knife then bought a new one but that is going the same way :sad:

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Interesting. I reckon it must be the o-ring as I can't imagine what else could cause this as the hard plastic isn't going to change shape, but there may well be something in the coolant that causes the rubber to swell. That said, it'd be a pretty poor design fault and surely would affect everyone.

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I had a look but couldn't really find anything. I might've been using the wrong search terms.

I'll replace the cap and see how I'll get on. I was confident that this would fix it, but Dez has given me doubts now... :wink:

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i have definitely read a few posts on this forum (or might be focus forum) about this exact same problem. it seems a lot of people experience this

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1 hour ago, MJNewton said:

I had a look but couldn't really find anything. I might've been using the wrong search terms.

I'll replace the cap and see how I'll get on. I was confident that this would fix it, but Dez has given me doubts now... :wink:

I just keep cheeking it now from time to time but I've had a wrench a round it to get it off 

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Thinking about this I don't imagine that the o-rings in the cap get much of anything in contact with them in normal use. The tank seems to be heavily baffled so there's likely not going to be much sloshing around so I think perhaps the o-rings (the bottom one at least) is possibly drying out,  hardening and expanding slightly in the process? I may try a smear of silicone grease on the new one and, as you have been doing Dez, undoing to periodically to keep things moving.

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This has been posted before, apparently it's a common problem. Ford service use silicon grease on the threads.

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The O rings do in fact dry out & swell jamming the cap solid, common fault on every ford going which has the same cap.

You'll need a new cap & silicone grease.

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Just now, karl46 said:

This has been posted before, apparently it's a common problem. Ford service use silicon grease on the threads.

Did my head in mate when mine was jammed in solid.

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Thanks everyone for all the responses. New cap it is.

I suppose one has to be forgiving of new-fangled technology of an expansion bottle cap... I even had to replace a coolant hose today because it had a metal section in it that had started to corrode. This car was made in 2013 yet some of its design choices seem to be more fitting of 1917!

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1 minute ago, MJNewton said:

 New cap it is.

Get some silicone grease and remove the O rings, give em a good coating then put the rings back on, then grease the inside of the plastic tank.

Since mine jammed I've been removing and checking my cap once a fortnight, re-greasing on every check... just don't want that to happen again.

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10 minutes ago, Ian Lanc said:

 

Aha! If I'd found that thread I would've been sorted. Apologies everyone for the repeat!

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Incidentally, rather than buy a replacement from Ford I'll get one from Gates instead and see if that last me any longer. (Of course, for all I know Gates makes the Ford ones!)

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Just bought one from amazon as mine was tight the last time I checked.....

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I purchased my cap from the dealership! Cost me £12 but was the only answer at the time as I needed one straight away and no motor factors had any stock of them.

Don't forget the grease guys or the cap will get stuck :sad:

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Yes same here,it never comes open a lot as long as its topped up,ford can deal with it on the services.

I had to use grips to get it open last time.

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9 hours ago, jace1969 said:

Yes same here,it never comes open a lot as long as its topped up,ford can deal with it on the services. 

You wanna be careful! Our local ford dealership wanted to change the tank & cap & fresh antifreeze + labour at my cost :rolleyes:

Purchased new cap, top of the cap came off which left a lower part stuck in, drilled an X shape into the plastic until it fell to bits, cleaned everything up, greased the rubber seals and fitted new cap = £12..... Hate to think how much the dealership would have charged me if i'd taken their route & advice :sad:

 

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19 hours ago, Ian Lanc said:

You wanna be careful! Our local ford dealership wanted to change the tank & cap & fresh antifreeze + labour at my cost :rolleyes:

Purchased new cap, top of the cap came off which left a lower part stuck in, drilled an X shape into the plastic until it fell to bits, cleaned everything up, greased the rubber seals and fitted new cap = £12..... Hate to think how much the dealership would have charged me if i'd taken their route & advice :sad:

 

I know our ford place very well so if there is any problem there the chap would tell me,been going there for years but i do see your point.

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Had you read the posts above, it has already been stated to use silicon grease on the 'O' ring of the new cap.

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5 hours ago, jace1969 said:

does a new cap solve it or does it just need grease or something on it as wont it just do the same again.

If you can get the old cap off without damaging it, then grease it up and re-fit it. :wink: If not buy a new cap. :whistling:

Personally I'd just buy a new rad cap, not like it's £50.

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