If I may, there are two types of blue caps: the one with the two valves on
the black rubber membrane is the right one for the vans, just had to found
out the hard way which one I bought. Brand new cap didn't open maybe a week
after I installed it, loosened the same hose twice, blew the coolant level
sensor twice, once at 2 am on my way to work... not fun.

The first time the coolant sensor blew out, I tighten every clamp down,
bled the system and thought that was it, wrong! The next morning it blew
out at abouut 4 miles from home. Replaced the cap with the old one,
installed a new coolant sensor, and apparently that fixed my coolant
leaking/bubbling problem. Tomorrow, to check the timing, loosing power
little by little. So, check which cap you have, who knows.

Hector
1990 Carat 'Ursula'

>
> hi ...
> Re pressure testing the cap ..
> have you made an adapter gizmo to be able to do that ..
> or found one to buy somewhere.
>
> so far..I have not found a way to pressure test those caps..
> Perhaps Stant or somebody has an adapter ...I just haven't found one yet.
> got a link ?
>
> additionally ...if you look in the waterboxer cooling system section of
> Bentley ..
> they show testing a pressure cap ..
> except ..it's a Diesel Vanagon style very conventional cap.
> They even tell the part # of an adapter..
> when you look that up ..it's for the Diesel Vanagon style cap, and I have
> that adapter since way back.
>  and I don't trust those blue caps..
> and always carry a spare ..and a spare pressure bottle on trips out of
> town.
>
> so ..testing the blue pressure cap .......??  anyone.
> thanks.
>
>