• Keith

DAF pump drive seal popping out.

If the drive seal/seals dislodge or pop out, it is due to an excessive build-up of internal fuel pressure in the high-pressure pump. The cause is either a blockage of the return from the pump to the tank or a problem with the Volume control/M prop. Valve.

Check the following.

Blocked/restricted return pipe.

  • The return pipe/pipes are all clear and not restricted.

  • The 3-way valve that connects the pump return and injector return to the tank is operational.

Volume Control Valve/M. Prop Valve.