Expansion Cap

[beachiain]

Hi All,
Hoping someone can help with this. I've got a 1.9Petrol '84 caravelle, I think the expansion cap valve is stuffed as the expanding coolant is pushing out via the cap seals rather than through the outlet. I bought a replacement from JK, put it on and got the same problem a few miles later. The original cap was black, the JK one is blue - I'm guessing there's a difference as the blue only apparently has 1 valve where the black has 2, does anyone know more about it and where I can get a black dalek cap?

Any help is much appreciated,

thanks

Iain

[Nicola&Tony]

Is the JK cap a genuine VW one? If not, that might be the problem. Try here:
Brickwerks cap

Tony

[Mocki]

check the bottle for hairline cracks around the thread , its common for them to do this, making it appear to be the cap when its really the bottle

[beachiain]

Thanks, I'll check the bottle then try Brickwerks. Chap at JK told me the cap had only 1 valve which got me thinking there were different types,

cheers

Iain

[Simon Baxter]

Chap at JK got it wrong.
There are a few styles, black, which now superceeds to the blue cap
The blue cap, earlier versions have 2 visible valves, on pressure valve and one vacuum valve.
They then changed to a new more reliable design that has a vented section that hides the valves, but it would not work if it had one valve.
The genuine VW ones work well, but the same company that makes them for VW also makes them for a few other people too.
I have genuine ones on the shelf and I have been trialling the aftermarket but OEM ones at the workshop and I have not had a problem with them so as soon as the VW ones run out I will start using the OEM ones as they are a little more affordable.
I tend to test parts on locals vans, it's not a massive problem if they fail then as I can see why and get them repaired again but this doesn't happen very often.

[waltraud]

Hi, interesting thread, hope you don't mind my joining on a sliught tangent- have had probs with an early style metal cap on 83 dg and wondered if the later- more reliable blue caps would also fit these- if not is there sense in changing to later bottle- early caps also seem v dear? Tim