Cooling expansion tank seal

[sidepod]

Word up,

When we first got our Cali it was losing water from the engine. Not a lot, just enought to require a top up each outing.
I couldn't find any evidence of a leak and there was certainly no water getting into the engine.

Eventually I traced it to a missing seal on the cap of the expansion tank (large clear plastic spherical tank on top of the engine).
Once replaced all returned to normal.

Now, three years on, the seal has gone again, as in, disappeared!! I have no idea where it's gone?

Has anyone else had similar problems? It's no biggy, a trip to the dealer for a new one. Bit odd though! :?

S.

 

[TwentyOneThirtyFive]

I can't say that I've ever noticed any kind of seal, but I've never looked for one. Is it just an o-ring? Will try and remember to take a looksee later.

Water is the one fluid we've not leaked. Yet.

 

[sidepod]

Yup it is an o ring, nothing techy. Just has a habbit of vanishing!

Regarding fluid loss, can I suggest a game of "Warning light Bingo" next time you're on tour?
Fairly self explainitory.......Brake fluid is the holy grail.

S.

 

[TwentyOneThirtyFive]

The fun of old vans eh? I know the oil warning light and buzzer works.

Ahh yes, the holy grail. 65mph on the M4, heading for south Wales. Failed to stop at Reading services...

Could have been worse I suppose, we could have been approaching the seven crossing toll booths :lol:

Anyway, I'll check mine later to see what it has. I have to remove it regularly as the pink plastic is no longer see through (going to change that at the next coolant flush as it annoys me). The cap is so tight I generally have to use a pair of pliers to undo it.

 

[sidepod]

The cap is so tight I generally have to use a pair of pliers to undo it.

Ah, that's the problem. Normally mine is only finger tight. Now the seal has vanished, it needs pliers to remove.

S.

 

[TwentyOneThirtyFive]

Right. I'll be missing the seal then.

Do you know the part number? Can't see one on GSF, only the cap itself, or on Europarts.

 

[sidepod]

Part number is...

1HO121687A

My analysis is it's a loose fit so when you remove the cap it drops off without your noticing...

Anyway, two on order from the Fatherland.

S.

 

[Harrydiver]

I know this thread is nearly five years old, but it´s the only one in the www relating to
the o ring 1HO121687A that´s supposed to go into the expansion tank cap. But how?
And where? Its measurements are 28,5 x 3,8. The valve inside the cap is 35 mm across,
so is the inner part of the expansion tank. Neither on the outside of the valve nor inside
the inner part of the tank is there some sort of groove that could provide a secure seat for the ring!
I´m flabbergasted... Hints anyone, please?
Harry

 

[Harrydiver]

The riddle is solved thanks to a knowledgeable vw parts guy - the o ring doesn´t come extra,
but is an integral part of the cap!

 

[J0Xd4E]

I was struggling to find this from the part number above, in case anyone else is looking it's a zero not an O, so it should be 1H0121687A. They are less than £2 on eBay.

Thanks for all the above posts, I'm hoping this is why my fluid levels dropped!