Hi there,

I had a question on how to refill the MCS in the event that it was drained. Do you refill it through that infamous leaky coolant tank or is there another location?

(I had a mishap with a road hazard and had to replace some parts underneath that required draining the radiator but not the AC)

Thanks!

 

You fill through the coolant tank, but you have to first open the 'vent' in the upper radiator hose first to allow the air out of the engine to allow the coolant in. The vent is the black plastic piece in the hose above the radiator. Loosen the screw head to open it, fill the coolant through the tank until coolant starts coming out of the vent. Start the engine momentarily, turn the heat on the highest position. This will move the coolant around and purge more air. Shut off the engine (no need to run it more than about a minute), reopen the vent, purge the air out, refill the tank to the 'full cold' level. Restart the engine like before, shut it off, and recheck the air and level. Once you arent getting much air out, make sure the level is right and put the pressure cap back on. Drive the car a short distance, then allow the engine to cool, and check the air and level once more, adjust if necessary.

 

I did as you instructed, but I can't get coolant to come out that vent when I fill it cold. The coolant will fill the coolant tank to the brim.

Suggestions?

 

You will probably have to start the engine periodically with the bleed screw opened (not removed, but a couple turns to allow the air out) to pump the coolant around and bring the air up to the highest point. Until the thermostat opens not all the air will purge. Systems like the MINI that dont have a cap on the radiator or the engine are a bit of a hassle to fill up in one simple action.