Ian, you are right, the cooler can be bypassed by putting the two hoses together. I ran mine,( not high speeds) for quite sometime before I replaced it. Volvo doen't have the part because it's a Hurth transmission part. It can also be bought in the States at Transatlantic diesel for 120.00 US. Phone !-800-9279295. Also they have any parts you need for the Volvo, talk to Sherrie. I think you have the same engine I have the Volvo TMD 22P Regards John "Moon dog" SM248