50 Series Workshop Manual
Remove the Pump
Lift pumps which are in an upright position (with the top
cover uppermost) are fitted to later engines. These are
secured with four studs, nuts and spring washers or
setscrews and two keeper plates fitted vertically be-
tween the washers and the outside of the pump mount-
1. Disconnect the pipes.
2. Remove the pump and joint.
To Dismantle the Pump (Fig. N.10)
1. Before dismantling, make a file mark across the
two flanges for guidance in re-assembly.
2. Separate the two halves of the pump.
3. Remove the diaphragm by unhooking it from the
rocker arm link. The diaphragm spring can now
4. Drive out the rocker arm pivot pin and withdraw the
rocker arm, spring and link.
5. Dismantle the priming lever by removing the lever
6. Remove the valves by levering from their locations.
Remove the valve gaskets.
7. Remove the pump cover and pulsator diaphragm.
Inspection of Parts
1. Check the diaphragm for hardening or cracking
and examine the pull rod for wear at the point
where it connects with the rocker lever link. A stem
seal fitted over the daiphragm shaft may be found
on some applications and should be renewed if
2. The diaphragm spring should be renewed if
corroded or distorted. Ensure the new spring has
the same colour identification as the original.
3. The valves should be replaced. The two valves are
identical and may be used for inlet or outlet (Fig.
4. Examine the rocker, arm, link, spring and pin for
5. Check the pulsator diaphragm for condition.
6. Examine the flanges of the two pump halves for
distortion. If necessary lightly linish to restore flat-
To Re-Assemble the Pump
1. Fit the new valve gaskets and valves to the body.
The inlet valve must be fitted so that it can open to
admit fuel. The outlet valve must be fitted in the
reverse position to the inlet valve. Valves are re-
tained by retaining plate or alternatively by staking
in six places with a suitable punch.
2. Fit the pulsator diaphragm and cover.
3. Insert the rocker arm pin through its hole in the
body, at the same time engaging the link and the
rocker arm. Tap the rocker arm pin in until it is
flush with the pump body. Stake the casting in three
places each side to retain the pin.
4. Place the diaphragm spring in position.
5. Place the diaphragm assembly over the spring, the
pull rod being downwards, and centre the upper
end of the spring in the lower diaphragm protector
6. Press downward on the diaphragm and make sure
that the downward tag on the lower diaphragm pro-
tecting washer is on the priming lever side of the
body. This tag is required to be in the hole of the
body ready for fitment of the priming lever. Engage
the diaphragm pull rod with the link and at the
same time match up the holes in the diaphragm.