Radiator hose coming off - '80 300D

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
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Look again at the neck. More than likely it is about a 1/2" to an inch long and has no raised rib on the end. If yes, look inside the hose for the broken end!. You need a new radiator.

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First, re the gas lid lock. The lid only locks when the doors are locked. It likely was working all along, you just never noticed it until you broke the vacuum hose, locking it permanently.
Are you sure you have the radiator hose all the way on, and the clamp is past the ridge in the pipe? Is the clamp real tight? It's not stripped is it? Once that clamp is on past the ridge, there's no way the hose is coming off.
Pressure isn't the issue, the relief valve on the coolant cap will open long before anything will blow.
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Karl,
You are absolutely right. I just checked and sure enough, there's about 3/4" of neck broken off inside the hose. I guess I never noticed the rough, broken end on the radiator.
Thanks for the tip!

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Re: Radiator hose coming off - '80 300D Group: alt.auto.mercedes Date: Sun, Nov 2, 2003, 2:36pm (EST-3) From: chicken snipped-for-privacy@hotmail.com (DarthHugsalot) Karl, You are absolutely right. I just checked and sure enough, there's about 3/4" of neck broken off inside the hose. I guess I never noticed the rough, broken end on the radiator. Thanks for the tip!
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 xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx send e your e mail addresses & will send you a website on raditors.
case
the case, minus a few cans!
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