BryanH19

I知 low on coolant and was planning on adding some, my question is how to burp the system. I want to know what I have to do. I know I知 supposed to add coolant through reservoir but is there something else supposed to be open?

TrueGS300

You will not be able to fill the system through the reservoir. Coolant can only be sucked in from the reservoir through a good cap on a closed system from the pressure drop as the system cools after shut off. You must fill from the radiator cap running and until the thermostat opens. This is messy without a proper fitting funnel but doable.

sbagdon

This is how we usually do this, when we're lazy... repeated cycles of hot/cool, to have the last remnants pulled in from the reservoir.

On the GS4, there's a coolant plug on the far front/left (when you're facing the rear of the car), that comes off, to get the very last bit of air... believe it's a 10mm 6-sided male socket (forget what they're called, same socket as the idler-pulley that is pushed by the tensioner), and the crush-washer is about $5 from Lexus.

We've had some real nightmare of cars... MR2s (or anything mid/rear-engine front-radiator) were a pain, it came with a burping tube from the factory, in the front of the engine-bay. And our old '00 Silhouette was a pain, as it had dual-zone cooling/heating, so you had to burp out the air in the rear-heat tubes, to get front-heat.