radiator hoses collapse when engine cools

[nefordfan]

I noticed that the radiator hoses collapse when the engine cools, I thought that the hoses were bad so I replaced them and noticed that they are still doing this. Is this something to be concerned about my temp gauge reads MA when idling and around L when cruising down the interstate. shrug

 

[Guy Newton]

You might be low on coolant, or maybe your t-stat is operating correctly

 

[Guy Newton]

You might be low on coolant, or maybe your t-stat is not operating correctly

 

[rangerj]

Check your overflow bottle and the hose that connects it to the radiator. Make sure the hose and/or bottle are not plugged. Also check the tube attached to the radiator. Then make sure the cap on the overflow bottle is vented. Also check youor radiator cap.

The coolant in your system expands when heated, and contracts when it cools down. The expanded fluid should flow to the overflow bottle. When the system cools down the fluid needed to fill the void is syphoned from the overflow bottle.

Your system is not able to syphon the fluid from the overflow bottle, and the vacuum is collapsing your hoses.

The hoses are most likely expanding when the system is heated up. You may "blow" a hose if you do not correct this problem soon. rangerj

 

[SHOZ123]

May be a bad radiator cap.

 

[Brian Smith]

would an excessively "hard" radiator hose, caused presumably by high pressure in the cooling system when the car is hot, also indicate this problem, rangerj?

 

[projectSHO89]

Brian,

It might. The radiator cap is supposed to allow coolant to go to the overflow at 16 psi. If the cap is not releasing at the proper pressure, the hoses will feel far more rigid.

If in doubt, just replace the cap (same for nefordfan). They're inexpensive insurance.

Steve

 

[SonicRiot]

You might have the wrong radiator cap or a bad one. Do a pressure test on both the cap and the system. Also, bring the car to full running temp, and then check the overflow. The coolant should come up or slightly over that highest knobular protrusion (!) in the inside of the bottle.

 

[dagcakes]

I had the same problem. Found the overflow bottle had a bunch of crud built up. After cleaning it out, no more collapsing hoses!

 

[etc1006]

Check the cap, definetly. I had a 94 E.B. Bronco 351 and it was doing that. I scratched my head for a week or so. Popped the cap off and the seal was shot. Apparently it was so old that it was sealing when it should have been letting the coolant from the bottle back in as it cooled. Hence the collapsed hose.

-Eric

 

[rangerj]

Just as a reminder for safety, folks;

DO NOT REMOVE A RADIATOR CAP FROM A HOT ENGINE, ESPECIALLY IF THE HOSES ARE HARD DUE TO A PRESSURE BUILD UP. Let the engine cool down for at least 1/2 hour before attempting to remove the cap.

An explosion of boiling hot water to the face, especially the eyes, would not be a very pleasant experience. rangerj