The smelly Westy rear heater core, (removal & maintenance)

The smelly "beast", It take 5 minute to get the sucker out from the camper version. 2 small screws, 1 connector and the 2 hoses clip. Be careful, you will spill some coolant on the floor.


Remove the 2 metal clip and pull out the front grill.


First remove the 2 valve screws.


Valve: The O-ring should be replace and seal (my idea) with Loctite 518 Sealant. My Westy rear heater is a bit smelly but i found no leak at all, nothing near the O-ring & valve or neither at the core that was also tested at 15psi!!!!, the valve by itself when true a 15psi test. You will see later that the core is in medium condition but NO lost of pressure at 15psi. Another Westy mystery...


Pull out the core and test this one to at least 15 psi.

Check for corrosion, mine is showing some at one end but it does not loose pressure. I think that when hot, it leak just a little bit and it's enough for a small smell in the van. (see picture below) $69.99USD!!!


You can see the corrosion here, probably I sign of fatigue. I am thinking of removing the rear core, I donít use this one at all and itís expensive to replace for something I donít use (summer camping only), I also would like the extra space under the benchÖ If you want to remove the rear core you simply have to remove or block the ďTĒ connector and the 2 hoses that goes to the heater.


  • A: To the front heater core
  • B: Up to the rear heater core (B is smaller, it act like a restrictor.)
  • C: To the big cooling tube between the termo. and the water pump or to the cooling distributor on the passenger side.

Compression test without a compressor and a gauge

How to make a compression test without a compressor and a gauge / regulator (That I have, sorry). Take a old bicycle pump (or similar), cut the end of the tube and make some kind of adaptor that will fit between the radiator / heater core and the pump tube. (you can find all kind of adaptor and fitting at any auto part or hardware store). Close the other end of the core with a 4 inches tube and a bolt. Pump air into core until itís hard to pump, you should have more PSI than needed; spay water and soap on core and look for leak. Another way is to fill the core with hot water, pump a few time and look for water leak.