Oh! The water pump.


“Diana”, our other DM4 Princess, had a bearing type noise issuing from the water pump which did not sound too healthy. To fix things I did the following, leaving the radiator in place.


  • Remove both horns
  • remove generator and coil
  • remove  fan
  • drain coolant
  • remove radiator hoses (not necessary but I wanted to change some welsh plugs as well)
  • remove heater hose from water pump
  • unbolt water pump, remove with a little effort because it had been there a long while.
  • clean exterior of water pump
  • remove pulley from water pump - do not loose the key from keyway
  • remove circlip and washer at front of pump
  • press out the impeller shaft
  • remove water seal from impeller end
  • carefully knock out the two bearings; spacer and seal into the pulley end direction
  • clean all thoroughly
  • the bearings supplied by John Neumann are sealed on both sides so leave them that way (you then do not have to oil them periodically)
  • carefully press in the internal seal making sure it the right way around
  • carefully press in the first bearing
  • insert the spacer
  • carefully press in the second bearing (when I say carefully, I mean make sure it goes in square and not at an angle otherwise damage might result to the parts))
  • insert the washer that goes under the circlip
  • insert the circlip ensuring it is fully located in the groove
  • fit the water seal (do not lubricate the face which mates with the impeller). you can put a very light smear of rubber grease to the rubber part which will assist in locating the seal. I must stress, be very careful fitting the seal and do not use excessive force. These seals are easily damaged.
  • refit the impeller shaft, making sure the spacer is lined up for the next step
  • fit the key into the keyway
  • Refit the pulley and tighten the nut.
  • Now is a good time to repaint the water pump
  • clean up the mating surface and remove any of the old gasket which may have stuck to the block of pump housing
  • I use aviation gasket glue on both sides of a new gasket (this does not come with the kit - I made my own)
  • fit the gasket
  • refit and bolt on the pump
  • during the course of all this is a good time to clean up the horns and generator and repainting (I use 'White Knight' gloss black epoxy rustproof paint in a spray can - about $13 / can - no priming required - but you must clean all the old paint off - have a clean surface and mask off areas you don't want paint to get into)
  • once repainted bits are thoroughly dry refit to car (I usually paint the day before refitting to avoid spoiling the nice finish of the paint)
  • You should also assess the condition of the radiator cap, fanbelt and radiator hoses and heater hoses while you are at it and replace if needed. I picked up fanbelt and hoses from SuperCheap. Take in your sample and go through the radiator hoses and pick one that will do the job after trimming off excess length. The radiator hoses I used are used on an EA Ford Falcon.
  • Refill radiator


As I said above I also replaced welsh plugs which adds a few steps. I actually found that the worrying leaky plug was actually fitted in back to front (that will do it !!)


Well there you go


Safe travelling

Joe Vavra