I had that EXACT same problem. It would be ok for a day or two, but the overflow would start to fill up and leak. I did the cap and thermostat thing, but it stopped when I replaced the water pump. Plus, I did bleed the whole system like a ****

 

do i just let it run with the cap off to try to get the air out? when i filled it up i opened the bleeder valve on the head. the water pump should only have like 1000 miles on it but it has been sitting in the basement for a while getting tossed around. was yours completely broke?

 

If it's new, I guess it should be ok?!? I hadn't messed with my cooling system, so I shouldn't have had any bubbles to begin with. I replaced the cap and t-stat. Replaced the pump and it was all good.

Anyway, leave the cap off and fill it to the top. Let it run at least until the fan comes on once and squeeze the radiator tubes a bunch to burp all those bubbles out. Make sure your heater temp is on hot too.

 

He has no heater, LOL!

Yea man, just take the cap off, and turn the car on, let that bitch warm up, my civic did that when i put my radiator in, i was like wtf, i put a new thermostat, and ---- in too, i was like OMG!