Radiator hoses collapsing?

[John_R]

I recently got a 93' 240sx Vert. I've been fixing a lot of the little problems (Tie Rod Ends, Belts, body panel alignment, etc. ).

Anyways, when I got the car it had flattened radiator hoses. So I pulled some off an S13 Parts car that were in good shape. drained the fluids, installed them, drove it a bit. Checked everything. Temp was down, fluids weren't leaking, everything seemed great. Took it on a small trip and opened the hood and found they had collapsed again.

What could cause this? I would assume that one side of the pump is blocked or something? Whatever it is, whats the first step to diagnosing this problem? (not to mention, there is a new water pump and new hoses, where to go from here?)

Thanks a lot guys!
John

[soreballz]

This happened to me over the weekend. You *probably* have air in the cooling system. Once I bled the system, the hoses stopped flattening.

[John_R]

Alright for the 3rd time I guess I'll try and "bleed" the system. I followed all the service manuals advice on how to bleed it.

Any specific advice I might need to know? (yes I am opening up the "bleeder" (air escape) bolt.

[Dream240]

The hoses collapsing is not the presence of air but the lack of it.

I would first check the thermostat - installed backwards? Also check the radiator for a clog. How's the coolant level at operating temp? Make sure the reserve tank is at the maximum level.

You might be getting vaccum into the cooling system, which could be a blown head gasket. What color is the coolant after you ran it and drained it? Any oil in it? Tailpipe smell sweet?

check these things and let us know what you find. GL

[Canaduh]

The hoses collapsing is not the presence of air but the lack of it.

I would first check the thermostat - installed backwards? Also check the radiator for a clog. How's the coolant level at operating temp? Make sure the reserve tank is at the maximum level.

You might be getting vaccum into the cooling system, which could be a blown head gasket. What color is the coolant after you ran it and drained it? Any oil in it? Tailpipe smell sweet?

check these things and let us know what you find. GL

Bang on. Get a water bottle, fill it up but leave a little space for air. Take the lid off, squeeze all the air out, put the lid back on tight. That's what's happening to your hoses. They're collapsign and have no air to get back to normal.

Kind of crude, but you get the point.