I can't get my water pump to circulate

I have a Mercedes 300SD that I am in the middle of a conversion on. We have the radiant heat system installed with the hose within a hose set-up. My WVO tank in in the trunk. For some reason the hot coolant is not circulating back to the tank. There are no kinks or other obvious blockages.

Anybody got any ideas?


getting coolant to circulate

It may be where you have T'd into the return line. If you have a secondary coolant recirculating pump under your air cleaner you need to T into the line before that pump(towards the rear of the vehicle. Do not T in between the pump and the engine.) That pump creates pressure on the output side(obviously) which makes the differential pressure between where you are T'ing in and where you have T'd off of the supply side low. This low differential pressure causes poor flow. If that is not it, check for air bubbles. If the lines are going up and down a lot air bubbles in them can hurt flow.

Reply to this post

Enter the characters shown in the image.