The G-P series uses a Stanadyne Model 75 secondary fuel filter in 1983. See Figure 4-16. It is fastened using two bail clips. It is particularly important to place absorbent towels under the filter when changing it to improve cylinder and case valley drain and prevent fuel oil contamination of the clutch driven disc.
The Model 75 filter is a two-stage pleated paper type filter. (Figure 4-16). The first stage consists of approximately 400 sq. inches of filtering area and will remove 94% of particles 10 microns and larger. The second stage is made of the same paper material and consists of approximately 200 sq. inches of filtering surface. The second stage is 98% effective in filtering the fuel already filtered by the first stage.
Particles which are larger than 10 microns may damage the pumpโs internal components. Figure 4-17 will compare various micron sizes and will ultimately show the filterโs effectiveness.
SECONDARY FUEL FILTER G-P SERIES
REMOVAL:
1. Engine must be turned off.
2. Remove engine cover.
3. Remove air cleaner.
4. Place absorbent cloth or towel under filter.
5. Unstrap the lower bail first to relieve fuel pressure in the filter.
6. Unstrap the upper bail and remove filter.
INSTALLATION:
1. Insure that both filter mounting plate fittings are free of dirt.
2. Install new filter; snap on the upper bail clamp only.
Anytime the secondary filter is removed or replaced, air must be purged from the filter to prevent engine stalling
or excessive cranking time to restart.
3. Disconnect the pink electrical wire from the injection pump to prevent the engine from starting.
4. Crank engine (for 10 seconds max.) until fuel is observed at the lower filter fitting.
5. If fuel is not observed after 10 seconds, wait 15 seconds, repeat Step 4.
6. When fuel is observed at the lower fitting, connect the lower bail clamp.
7. Reconnect the pink wire on injection pump โ and install air cleaner.
8. Start engine and allow to idle for several minutes to purge remaining air, โ check for fuel leaks.
9. Remove absorbent towel from filter area โ reinstall engine cover.
