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Volkswagen Repair/bleeding a engine cooling system


Big Wrench wrote at 2009-03-23 19:35:01
VW Passats are notorious for AIR POCKETS within the system once it has been opened up or drained.

We use a Vacuum pump to draw down the system and then use the pressure differential to suck the new coolant into the system.  AIR LIFT is the name of the tool.   Good Luck;.  

40 years of experience working on VW's!

VWGURU wrote at 2010-07-25 01:20:45
Rick is not fully informed...

There is a bleeder HOSE at the heater core fitting on the fire wall. Pull the hose on the passenger side back until the bubbles come out. You are going to have to unscrew the coolant reservoir and lift it up a bit to make it higher than the bleeder.

Trust me. This is how you bleed a VW v6.

I realize this is old, but thought I should elaborate in case some else comes along this post.

Charles wrote at 2011-11-27 06:42:14
There is no heater control valve in this car/engine just a blend door. There is a bleed screw behind the drivers side head, it is a gold bleed screw in a black metal pipe, there is another right behind the fan same gold screw. and yes you DO have to bleed the air out or the car will over heat / the heater wont work. Also there is a small bleeder hole in one of the heater hoses that go into the heater core right nevt to the battery. Did you ever get this working?

steve wrote at 2014-02-05 00:32:10
I have personal experience with having to bleed air from a newr type of cooling system on a Chrysler. It actually has a "Bleeder" valve threaded into the intake manifold. I don't remember what year the car is but I have noticed that since the manufacturers changed the cooling system by removing the radiator cap and moving the filling opening to the "Overflow/expansion tank" that it has become necessary to bleed air from some brands.

Michael wrote at 2014-12-16 11:35:54
I'm surprised at your answer because you are supposed to be a mechanic. I have bled the cooling system of a 1994 Golf 3 GSX that was overheating and that is 15 months ago and it has never overheated again.

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Rick O.


Classic, aircooled (rear engine) 1949-1979 VW's, specializing in electrical problems, fuel injection, and Type 181 "The Thing". NOTE: I have limited experience on water-cooled VWs (Rabbit, Golf, Jetta, etc...) but I am glad to help to the extent of my knowledge, due to the fact there are currently no other experts registered for these models.


15 years of aircooled VW ownership and maintenance.

Wikipedia, VW Beetle

Retired US military Electronics Tech/Master Training Specialist, Civilian Computer engineer.

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