About two weeks ago I flushed the radiator in my 1980 300D. Everything seemed fine, just routine maintenance.
(I did break off a little plastic nub at a T -junction in a vacuum hose, but it wasn't attached to anything vital, so I just taped off the hose. Just after that, I noticed that my fuel tank lid was locked. Apparently this car has a vacuum locking system that's never worked since I've had the car. I had to dig around in the trunk to manually disengage the locking bolt. But I don't think that's related to this problem.)
Twice while I've been driving these last few weeks the upper radiator hose has slipped off the radiator. I've noticed the temp gauge rising quickly, stopped the car, and then re-attached the hose. Both times it's taken over 2 gallons of water to refill the system.
I don't think the brief temperature rise damaged the head gasket or anything, since the car still runs fine. But I don't want the hose to come off again! What could cause enough pressure to build in the coolant system that it would blow the hose off the radiator?
thanks in advance for the advice,
Nick p.s. the email address doesn't work