hello, most likely too late, but if you need to transport the defective
vanagon, you can get a hose repair kit at local auto stores. This consists
of a sleave that will slide over the ruptured part of the hose.It will
shrink and seal the hole temporarily.Also, if you relieve the pressure by
loosening the cap. you can most times drive quite a ways.Also , turn on
your heaters for cooling of the vehicle(not you).I think you are talking
about the hard plastic piece that looks like an H. Bus Depot has this cheap
or you can get it from any pre 86 vanagon(junkyard?)Good Luck!