overheating problem

hi ive just had my head gasket done and now the heater matrix has just gone so ive bypassed the matrix and now its overheating and seems to be over pressurising anybody have any clues what to do? ive been told to get the head checked and see if thats at fault so any ideas will be helpful

have you checked rad is hot all over when engines upto temp ,top hose hot proving thermostats open ,all other pipes are hot proving good circulation

the rad is about knackerd its the garage did a leakage test i think it was likie a big pipet with a red liquid and air was ****ing through if this helps many thanks

not just a leak test but effective cooling ,thats why you feel it all over to ensure its cooling all over if not replace ,if rad cant cool theres no point in doing anything else

ok thanks i will give that a try

hi i ran it up to temp and the rad was hot allover i took it for a run after 5 mins all the heaters were working then 10 mins after that the temp just shot through the roof pulled up and the expansion tank it was like rattling like it was boiling so we opened it to drain slowly and left it to cool then topped it backup and set off home and the needle was up and down like a yo-yo?