Coolant system bleeding
I'm just starting the re-assemble of an oil cooler seal job, and hoping to gain some progress in next few days.
Wondering if there is a procedure that works well for bleeding the air out of the coolant lines in these engines?
Previous cars i've had, there were bleeder fills and what not, but not sure how this one works.
2013 GL350.
Cheers,




Don't know if you are familiar with the fact that closed thermostat holds air bubble till it opens, but I made easy system for filling the coolant:
- top off the coolant reservoir on cold engine.
- take some extra coolant in the trunk and take the car for a drive on road with not much traffic
-once you see the engine reaching thermostat opening temperature (80C on most of the engines) - pull over.
- using gloves open the reservoir cap, making sure your coolant is not steaming.
-once you open the cap, add coolant from the trunk to top line on reservoir.. On my cars it usually it a reservoir neck where the hot coolant suppose to end.
MB build reservoirs with filler tube below top level, so there is always some expansion air in it.
Also I made mixing the coolant easy job.
When most of cars system takes 8l of coolant, I live in warm climates and don't have to worry about perfect 50-50 mix with water.
So I pour 1 gallon of coolant concentrate and top it off with Distillate Water. That gives me about 45% mix, what works for me.


