trouble shooting tips No. 15 Sealing MTI (D&H) Pulsers to Prevent Water Wicking up ShaftPublished: July 2, 1999
Water is the biggest cause of Pulser Failure on D&H EQ30 Heads! Almost 90 percent of the units being returned under warranty have signs of moisture having been present on their shaft.
We think the problem comes from condensation forming on the metal plate on which the Pulser is mounted, then running down under the Pulser and down it's shaft where it "wicks" up the shaft and into the Pulser.
We suggest sealing the Pulser after it is mounted by running a bead of silicon around it to prevent water getting underneath it (see Figure 1 below). We are ensuring that any Pulsers shipped from National Parts Distributing Ltd. have been sealed at any joints in the Pulser and where the wires enter the Pulser. If you have a Pulser which is not sealed you should also seal all joints on the body and where the wires enter with silicone.