Top coolant hose cold after matrix replacement

[kpm278]

hi

Had the heater matrix replaced. Was fine for first 100 miles then yesterday when I pulled up the fans were at full pelt and the hose from the expansion tank was cold and empty. The tank had coolant in it. The heater matrix pipes were hot. Temp gauge showed 90 (I know it can be anywhere between 80-105). I drove home and when I pulled up fans were off and the hose was hot.

Air lock?

Thanks, Kristian

 

[Svenedin]

Sounds like an air lock. The cooling system is supposed to be filled under vacuum. Possibly if the coolant reservoir is put under vacuum the air lock might shift.