Upper radiator hose

[Gary V.]

What would cause the upper radiator hose on a 79' small block 350 to look like all the air was sucked out of it from the inside? I found it that way a week after driving the car. I loosened the clamp on the thermostat housing and it came back into it's round shape again. I drove the car and everything seems fine. The thermostat opens and temperature is in spec. Water pump is good and no leaks. I had heard that the lower hose has the spring in it to prevent it from collapsing like this upper hose did. any thoughts?

Gary

[Duke W.]

Re: Upper radiator hose

The cap has both pressure and vacuum relief valves, and the vacuum side may be malfunctiong. Most auto parts store have radiator cap pressure testers, and they might also be able to test the vacuum relief function.

If it happens again, slowly open the cap and listen for the sound of air rushing in.

Duke

[Gary V.]

Re: Upper radiator hose

Thanks Duke,
It happened again and I did hear the air going in and the upper hose went back to normal diameter. I replaced the cap with an NOS OEM AC Delco replacement one instead of a re-pop that was on there. I will let you know the outcome.
Gary

[Gary V.]

Re: Upper radiator hose

The new OEM cap fixed the problem the system is working like it should drawing from the coolant recovery bottle, not collapsing the upper radiator hose. Thank you for the help.

Gary

[Joe L.]

Re: Upper radiator hose

The new OEM cap fixed the problem the system is working like it should drawing from the coolant recovery bottle, not collapsing the upper radiator hose. Thank you for the help.

Gary

Gary-------


....just another example of functionality problems created by reproduction parts. In this case, the vacuum relief function of the reproduction cap must be non-functional. Maybe they didn't even include such a function in the design.

[Gary V.]

Re: Upper radiator hose

Hi Joe,
I couldn't agree more! The biggest problem restoring this car has been reproduction parts and fasteners. Many were poor quality and had to be replaced more than once. Others like this cap created problems. It's a shame because I don't even drive the car that much for things not to work right or fall apart or leak.


Gary