cap of radiator expansion bottle

[gaz1]

There is a constant small bit of green coolant sitting on the top of the bottle just around the neck where the screw cap is located, it's just a couple of mm wide. The coolant level is not dropping, nor does the coolant look discoloured or oily. It's a V6 but the radiator setup on either engine looks pretty much the same.
The cap doen't have any sort of sealing washer/o-ring in it to to seal the gap when it is screwed down onto the bottle, and none of the illustrations I can find in workshop manuals for Gen 3 and 4 Pajeros show a washer - should there be one?
If it's supposed to have be one there, I'm sure MM will have an exorbitant price for it - probably have to buy the whole bottle and hose! (or find a substitute).

[rgrubby]

Mine has a washer. It's a very thin flimsy one, but it is 12 years old

[aussieintas]

Yep they have a washer that is part of the cap and tube that goes in the bottle. Pic below shows the item and part number.

[aussieintas]

Sorry forgot thr pic.

[gaz1]

Thanks to NZ and Tassie for the quick responses. Is the washer that you describe the thin black flat piece of rubber that is part of the top of the tube leading to the bottom of the bottle? Mine is there, but it's quite mis-shapen and doesn't nearly cover the round circle of the cap that it sits on - its also off centre.
Or is there also another separate washer that fits up inside the white cap and presses on the thread of the bottle when screwed down?
Cheers

[rgrubby]

Sorry I didn't look to hard. I just happened to pop it off for a look while I was removing the battery try and remember the thin washer was not secured to anything, just sitting there and I had to line it up to put the lid back on. I didn't look under the lid to see what was there

[aussieintas]

It has a washer on it further up that seals agai st the white plaste neck of the bottl....See pic below you can just see it. According to Partsouq.com the washer isn't a separate item.

[gaz1]

Eureka! that's solved it......the black flat washer that's showing up partly inside the screw cap is missing from my car. How it disappeared is a total mystery, probably fell off down into the engine bay without me noticing it. Now to see if I can find something suitable to replace it rather than having to buy the whole thing.
Many thanks for your help.