LPG Discussion Forum

My filler dust cap has become increasingly hard to pull out. Turning it is fine, but then tugging it out usually requires a pair of pliers. I've made sure everything is dead clean and have tried to apply a bit of grease around the edges, but this only cured the problem for a couple weeks. This seems bizarre seeing as it is simply a piece of round plastic with nothing (on the face of it) to go wrong. It's as if it has expanded :s.

Has anyone experienced this before and knows of a cure? Is it worth purchasing a new cap or has the actual recess shrunk somehow...

If the filler housing has been put in on a curve it can go oval. Also over tightening the nuts at the back can cause the similar effects.

May be on to something there. I'll try loosening the nuts when I get a chance. I presume that once the housing is distorted, it will need replacing and it's not something that can be DIY'd as the filling valve needs to be removed first?

Do you still have the plastic wire hanger that hols the cap? If so, it's likely the wire is getting trapped either inside the bayonet, or on the side of the cap, seen both.
Let us know?
Huw

Could be that it's over-tightened, unequally tightened, mounted on too much of a curve or that the plastic hanger is getting trapped... but...

Not all plastic filler housings are the same... The cheaper ones deform much easier than the 'normal' (bit more expensive) ones.

In the words of a well known and respected supplier "Would you like the normal filler housing or one of the cheaper ones that we now supply - to compete on price with some of the Polish suppliers whom only supply the cheap copy type filler housing?". Decent installers should say "Please only supply me with the more expensive filler housing...".

The cheaper type are also prone to falling to bits - the cap comprises two plastic mouldings stuck together, the spring loaded cap securing mechanism pushes the plastic top half of the cap away from the lower plastic half (the part which secures on the bayonet) .

They all look very similar.

Simon

minimutly wrote:Do you still have the plastic wire hanger that hols the cap? If so, it's likely the wire is getting trapped either inside the bayonet, or on the side of the cap, seen both.
Let us know?
Huw

The wire is still there and I have double checked it's not getting caught.

LPGC wrote:Could be that it's over-tightened, unequally tightened, mounted on too much of a curve or that the plastic hanger is getting trapped... but...

Not all plastic filler housings are the same... The cheaper ones deform much easier than the 'normal' (bit more expensive) ones.
Simon

Mine says 'Autogas' on the cap. I presume this doesn't mean anything though in terms of figuring out whether the housing is a knock off or not?

Thats probabbly the two piece one, the one piece ones are usually blank. Don't think its a case of a knock off as such as there isn't an "official" product as such, just the quality varies (the replacement filler caps of the other type where its all one piece i've found to be hopeless - they work for a couple of months and then the clips break off).

The one you have is the 3rd one down on the right by the sounds of it on this list

http://www.tinleytech.co.uk/acatalog/Fi ... _caps.html

where you say greasing the filler helps for a short while suggests the grease works until its washed off (by the propane when filling/scraped off by the filler gun).

I'd try a filler cap first, changing the filler involves releasing the gas in the line between the filler and the tank (the tank should have a non-return valve fitted). Removing it isn't too major, but making sure it doesn't leak after refitting and that its vented correctly if it does leak at a later point may make it easier to get someone to do it for you if your not confident in doing it (bear in mind you won't be able to detect a leak until you fill up next)

If the filler is distorted i'd expect you might see contact between the cap and the filler when the cap is in place as well, if you can't see this (the gao appears the same all the way round) it suggests the cap is at fault (sticking on the bayonet filler) rather than the outer housing.

get a bit of sandpaper on it - worked for me.

Had a crack at this today. Loosening the housing screws and manually stretching the housing out didn't make it any easier in removing the cap. A replacement cap fitted perfectly. However, seeing as I wanted my original cap retained on the plastic wire, I set about following hitman's advice. I connected it to a drill and spun it around sheets of sandpaper (120 through to 2000 grit). Fit's perfectly now, if anything it comes out too easily .

I did notice that as Simon [LPGC] mentioned, it is made of two parts (the outer piece which you turn and inner which locks around the filler valve) glued together. There is a marginal gap around the outer piece where it may very well have become unstuck and expanded.