Coolant Hose
 

1993 CivicAuto..
What cause the coolant hose to collapse after the the engine is shut off.

Any ideas...is there air in the cooling system?

Thanks

there was a thread about this not so long ago. i never checked to see if the guy ever figured it out.

I hope this helps,

As the engine cools after shut-down, the coolant contracts. Normally, reserve fluid is drawn back into the system from the overflow bottle, and yes, a slight vacuum is formed to do this. If the return path has too much restriction, the vacuum increases and can collaspe a hose. However, a proper hose should have enough body stiffness to withstand the ususal amount of vacuum and should be able to draw fluid back into the system. Deteriorated hoses may collaspe. Another cause is that the hose was not the proper one, or good one, in the first place and did not have body stiffeners within it. Sometimes, the bottom radiator hose may have a spring-like coil of wire in its body; The upper one may, or may not have such stiffeners.


Places where restrictions may occur in the return line (from the overflow bottle)
- Wrong radiator cap, or one with a stuck or plugged valve.
- Collasping hose from the radiator to the overflow bottle.
- Gunk in the bottom of the overflow bottle getting sucked over the return opening.
- Interference on the hose going from the coolant system to the overflow bottle, like a mounting clamp pinching this hose.
I presume this is a new problem that has developed lately, therefore its a good bet that both (upper and lower) radiator hoses should be relaced. And while these are off, its a good idea to change the thermostat too.

he pretty much just covered it all for you ...the thing that would jump out most to me for this particular issue would be #1 &3