Originally Posted by Alvyn
ps I think Bailey's use a darky blue coloured cap(sort of domed shaped) IIRC
Edited (thanks to Spenner):
Yes Alvyn, the Bailey header tanks come with a higher pressure cap (i.e higher pressue than the standard Ford yellow cap)......
The Bailey tanks use the Audi/VW dark blue pressure cap, important to note that these caps have a different diamater & thread size to the Ford items, so you cant just fit these dark blue VW caps to a Ford plastic header tank or to "some" Spec-R header tanks.