top radiator hose collapsed

[pimpmyc250td]

hi

just found the top hose on my c250td flat rather than round,as if the system has a vacuum, car is not losing fluid temp never gets above 80

i changed the expansion cap last week, so is this related ( just put the old one back on)... hose is now back in shape, after taking the expansion cap off ....is it a sign of an underlying problem....

top hose is still warm, bottom cold , radiator cold,

I was planning a system flush out at some point should i change the thermostat too, and get on with the flusing???

 

[Mercsys]

Looks like the new cap is not rated to the correct spec, or may be faulty, there is usualy a very low neg pressure rating spec. The new cap doesent seem to be doing what is needed, your hoses wont like being squashed and then pressurised.

 

[pimpmyc250td]

Thanks...new cap was source
From ecp...I will pick up a New mb cap, and swap out the top hose as its very soft