Suspected head gasket failure

[ShadowSoul]

After driving it for a few days I thought I would try collecting the gas from the rad to see how much there is. I'm not exactly sure what I hope to achieve, I'm just curious.

Using an upturned jug in a bowl I measured just about 100ml. Interestingly, no air came out when I first opened the bleed screw (with the expansion tank open), air only came through when I started the engine.

I've reset the trip odometer and drawn a line on the expansion tank. In a while I'll look again to find out how quickly the gas is collecting and whether it is losing coolant. At the very least maybe I can estimate how far I can drive before the coolant return pipe starts sucking air.

Any other ideas how I can determine what's going on? Is it time to admit I need a mechanic?

[Carolyn]

Have you changed the O rings on the radiator bleed and drain?

[ShadowSoul]

No. Just whatever came on the toyota part.

[Call the midlife!]

I'm not expert but if you're trying to bleed it with the expansion tank open you're not going to be pressurising the system, you're also at risk of losing coolant by boiling out of the expansion tank.