Hints and Tips



Jabsco Heads (WC) Service

The standard manual Jabsco head fitted as standard to many Jeanneau's after a season or so will often become progressively more difficult to use and will probably start producing annoying squeaks. This is simply because the grease that lubricates the plunger tends to disappear. Fixing this is neither difficult or particularly unpleasant if a few basic steps are taken.


With the newer "Twist and Lock" version this is quite simple:


• Fully flush the head by pumping plenty of water through the unit.

• Turn off the inlet seacock



• Lift the plunger fully up, then unbolt the screw ring


- the entire plunger can then be removed, cleaned and greased - Jabsco specify Vaseline/petroleum jelly, but I find that white marine PTFE grease is great and I have not seen any seal damage as a result. Then reinstall - take care not to overtighten, a couple of turns of PTFE thread seal tape may be used if there is a minor leak


• If you need to do a complete service the following notes and images should assist, but also look at:

Jabsco instructions


• Disconnect (simply pulls off) the white inlet pipe behind the pump handle

• Move the valve lever to the left - as shown above - this is important - pull the pump handle fully up, then remove the six screws

• Ready to lift pump out.


• Grease the plunger shaft and around the large O ring and also grease the cylinder walls - I use plenty of white PTFE grease, which is probably better for the seals than mineral grease (or Vaseline petroleum jelly)


• Clean or renew the top gasket assembly, then ensure that the gasket and seals are properly located


If you have any leak around the plunger, you may need to replace the top seal (included as a complete assembly in the Jabsco service kit)


To avoid damaging the the new seal wrap the threads with PTFE tape as shown below:


• Reinsert the plunger and top assembly, ensuring that the valve lever remains shifted to the left, and that the top fully beds into position


• Replace the six fixing screws and evenly tighten.


• Open seacock inlet then test pump - check for leaks and correct functioning


• If you need to replace the "joker valve" which stops backflow from the waste pipe from re-entering the bowl then after ensuring the seacock is closed disconnect the water inlet pipe as shown below:


• Next unscrew the 4 vertical base screws and then the 2 that attach the main outlet hose

• Image above shows a new joker valve fitted in the outlet pipe and the new base flap valve in position


• When reassembling ensure that the 2 screws attaching the clamp ring on the outlet pipe are secured before attaching the 4 baseplate screws as the pipe may stop the joker valve seal from correctly bedding


• Open seacock inlet then test pump - check for leaks and correct functioning


Malcolm Perrins