Jesper and I have been using the Dolz T116 pumps for parts to renovate the original T158 pumps. Taking them apart and only using the shaft, bearings and seals, Jesper has renovated the T158. He uses the original cast iron impeller but have to mill off a few millimetres to allow room for the new, different seals from the T116. Also the pulley end of the shaft has to be cut about a centimeter shorter.
Not a difficult project and while I thought that my rebuilt pump had failed, it looks like the problem was the old hose leaking around the top of the pump.
Still looking for a replacement. May end up using two 90 degree pieces and a fitting to join them. That is, if there is room for that. It was a tight squeeze getting the hose off, disassembling only the thermostat housing, in order to get a pair of polygraph pliers on the spring-loaded hose clip.
Well after replacing the hose, only to discover that water still leaked out, Jesper and I removed the pump.
It looked like it was ok and we tried air pressure from the pulley end and it was tight.
However using a syringe with a plastic tube inserted into the bearing vent hole under the pump, we forced water into the housing between the bearings only to discover that it leaked through the inner seal. Closer inspection revealed that the collar around the seal had cracked, thus allowing water to seep past and out the vent hole. Angry
Another Dolz 116 will now be sacrificed to rebuild the pump. We are not using the original pump that failed first.
Taking it apart we found that the bearing and balls just rattled out. The shaft had a grove worn where the bearing had been. It must have partially failed at some time in the past, but because the vent hole was completely clogged, water didn't leak out until the bearings completely failed and water leaked out around the shaft at the pulley end.
The photos show the bad state of the original pump. Shocked (The housing is salvageable though)
The last photo shows the failed Dolz-116 seal from the rebuilt pump. At 2 o'clock you can see a crack in the ceramic ring and cracks in the rubber surrounding it. We do not know if that could have happened during the rebuild, but Jesper went to great k´lengths and custom made tools to fit it this time.
This pump seems to be holding tight. But there still was a leak. It turns out that the small hose from the thermostat housing to the expansion tank is/was leaking. I have tightened the hose clamp hard, and will see if it can be tightened further tomorrow. But for now it seems to be tight.