Best way to bleed air from Heater Core?

[sometoyotaguy]

My wifes 95 corolla has an all but useless heater. Both hoses seem hot, and the valve seems to operate properly. The temp gage registers about halfway once it's warmed up.
I changed the thermostat awhile back, but that didn't seem to help. Would air trapped in the core cause that issue? The air coming out is only about 90 degrees. I looked around in the old threads, but didn't find much of anything. I do have a new water pump, so I know that's not the issue.

Flushing the core isn't much of an option since I'm pretty sure it has a pinhole somewhere. The windows get a haze on them after awhile. It should be changed, but I'm trying to get the winter out of it. I don't have a garage, and the driveway is a cold cold place to work.

What's the best way to bleed the air out?

Thanks.

[Rip The E Brake]

Its time to replace the heater core. Its pretty hard to burp the heater core without gettin in there.

[sometoyotaguy]

I'd still have to burp it if I replace it. Is there a usual procedure, or is it supposed to just work itself out?

I'm tempted to try a new thermostat since it looks like they sometimes are weak/bad out of the box.

Thanks

[ShawnM]

Bleeding these older ones is pretty straight forward. Ive never had any issues with just letting it run with the cap off till the radiator fan kicks on. The air usually just works its way out. I you think you still have air trapped in there you can elevate the front of the car during the bleeding process since air will make its way to the highest point in the system.

[Bitter]

somtimes holding a fast engine speed with the cap off for a minute or two will get the air purged out, hold like 2500 rpm for 1-3 minutes and see if you get some air out.

[speedy25]

Its not air trapped in the heater core, its corrosion!

No heat output because its blocked. Sometimes a flush can help, but usually since the cores passages are much smaller than the adiators, they just stay plugged.

Sorry to give you the bad news in January!

-SP

[fast68]

time for new core regardless.

bleeding them is never an issue

if there is leaking then its bad

and if theres no heat then either the blend door is stuck inside the box assembly

or the core is junk

if you know that the door inside the box moves when you move the selector from heat to a/c then the core will be the culprit