I found the source of my coolant leak- my old cap was leaking coolant and not holding any pressure so I replaced it. All's was well until I was out on a pretty warm day, checked under the hood the next morning and saw my upper and lower radiator to water pump hoses were collapsed.

I saw some posts that said if your hoses are collapsed to replace your cap... so what could be going on? I never had collapsed hoses with my old (leaky) cap.

__________________
1993 320TE M104
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past:

1983 230E W123 M102
1994 E300D S124 OM606 (x2)
1967 250SE W108 M129
1972 280se 3.5 W108 M116
1980 280SE W116 M110
1980 350SE W116 M116
1992 300E W124 M103
1994 E280 W124 M104
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"music and women I cannot but give way to, whatever my business" -Pepys

Cooling system caps have both pressure and vacuum relief valves. A collapsed hose indicates a vacuum relieve valve problem. Could be the new cap is defective.

Duke

Defective cap as it has been said or a kinked /blocked return hose from the rad to the expansion tank.

thanks for the replies.

I tried swiching back to my old cap for a bit- noticed the coolant rises about 1cm in the tank after about 5 mins.

With the new cap it's a lot slower to rise, and by not as much. Tried the new cap again last night and this morning only the upper rad. hose was collapsed.

__________________
1993 320TE M104
---------------------------------------------------
past:

1983 230E W123 M102
1994 E300D S124 OM606 (x2)
1967 250SE W108 M129
1972 280se 3.5 W108 M116
1980 280SE W116 M110
1980 350SE W116 M116
1992 300E W124 M103
1994 E280 W124 M104
----------------------------------------------
"music and women I cannot but give way to, whatever my business" -Pepys