Since January 1985, a new filter began to be installed. It has a diaphragm pump to remove air from the fuel system. Since July 1986, a filter with an indicator of the amount of accumulated water condensate has been installed. This filter was supposed to be replaced every 30,000 km.
To drain the water condensate, connect a small hose to the fitting (3) in Figure 363, and place the other end in a container provided. Open the air bleed valve (2) and loosen the screw (3) a few turns. Drain approximately 100 cm³ of fuel and water. Tighten the fitting screw.
Figure 363. Fuel filter. 1. The drain nipple (3) can also be located on the bottom side.; 2. Hand pump button; 3. Air bleed valve; 4. Drain nipple
On older filters, the drain plug is located on the bottom of the filter. Holding a container under the filter, pour the leaking liquid into it.
The filter element is replaced as follows:
- Drain the fuel from the filter as described above.
- Depending on the installed filter, when replacing the filter, use Figure 364 or 365. The filter housing is attached either from the top or from the bottom. Unscrew the bolt and remove the filter housing, followed by the filter element.
Figure 364. Disassembled fuel filter (release before January 1985). 1. Bolt, 10 nm; 2. Sealing rings; 3. Fuel nipple; 4. Air bleed valve; 5. Filter element; 6. Filter housing; 7. Mounting bolt; 8. Hand pump piston; 9. Drain plug
Figure 365. Filter element 1. Sealing rings; 2. Mounting bolt; 3. Sealing ring; 4. Filter head; 5. Air bleed valve; 6. Fuel nipple; 7. Filter housing; 8. Water condensate sensor; 9. Drain plug
- Thoroughly clean the bottom of the housing and install a new filter element. Both sealing rings (2) in Figure 364 or the three sealing rings (2) in Figure 365 must be replaced. Also check the position of the sealing ring under the bolt head.
- Place the hose on the air bleed valve (from below or from the side) and open the screw.
- If the filter has a helical gear, unscrew it and pump with a hand pump until fuel flows out of the hose without containing air bubbles. If the filter has a hand pump button (release since January 1985), shown in Figure 363 (position "1"), press it until fuel flows out of the hose without containing air bubbles.
- Close the air bleed valve and tighten it on the filter with a screw gear.