Fluid Pump, Multi-disc Brakes B1 and B2, Overhaul (AF 20/22) No overhaul work is required at the fluid pump, as no individual parts are available from the supplier. Therefore disassemble/assemble fluid pump only for cleaning purposes.
 Inspect Check easy turning of fluid pump drive gear - insert KM-704 in spline of fluid pump shaft and turn in both directions. Check function of multi-disc brake B1 - blow in low-pressure compressed air (4 bar) (arrow 4). Piston must move uniformly and actuate the inner lining plates. Check function of multi-disc brake B2 - blow in low-pressure compressed air (3 bar) (arrow 4). Piston must move uniformly and actuate the outer lining plates. | 
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 Disassemble Disassemble multi-disc brake B1. Remove retaining ring (2) with screwdriver, brake flange (1) and clutch discs. Remove spring plate (4) from housing - compress under a press with KM-699 (3), remove retaining ring with retaining ring pliers. | 
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 Remove, Disconnect Remove piston for overrunning clutch F1 (1) - blow in low pressure compressed air (arrow), if required assist with pliers, replace rubber O-rings (2).
Inspect Check sliding surfaces of the lining plates for wear - if required, replace. Place new lining plates before installation in transmission fluid for at least 2 hours.
Disassemble Disassemble multi-disc brake B2: Remove retaining ring (4) with screwdriver. Remove 1 brake flange (6). Remove lining plates (5) and steel plates - exact number see "Technical Data", section "Parts List". Remove 1 brake flange (not for all transmissions) and return springs assembly (3). | 
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Remove, Disconnect Remove piston for multi-disc brake B2 (1) - blow in low pressure compressed air (arrow), if necessary assist with pliers, replace seal rings (2).
Inspect Check liner in pump housing for damage and/or wear, replace fluid pump completely if necessary. Check both sides of plate for scoring and wear, replace fluid pump completely if necessary.
Remove, Disconnect Lever out fluid seal ring from pump housing - with screwdriver, do not damage seat in housing.
 Assemble Fluid pump. Drive in new fluid seal ring with KM-674 flush with housing upper edge. Illus. D 0201 shows operation with installed fluid pump. | 
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Inspect Check easy turnability of the drive gear of the fluid pump - insert KM-704 in toothing of the fluid pump shaft (1) and turn in both directions (2).
Assemble Assemble multi-disc brake B2: Insert piston for multi-disc brake B2 with new rubber O-seal rings into stator shaft (spring mounts face upwards). Place return spring assembly (3) onto piston. Insert 1 brake flange (not for all transmissions). Alternately, insert steel plates and lining plates - for AF 20, 3 of each (5), for AF 22, 4 of each - steel plate first, flange (6) last (rounded side points to lining). Fit retaining ring (4). | 
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Assemble Assemble multi-disc brake B1: Insert piston for overrunning clutch F1 with new rubber O-seal rings into stator shaft (spring mounts face upwards). Insert spring plate (1) - compress with KM-699 (2) under press, fit retaining ring with retaining ring pliers. Alternately, fit steel plates and lining plates, steel plate first, steel flange last (rounded side points to lining). Fit retaining ring - screwdriver.
 Measure Measure piston stroke of multi-disc brake B2 with Dial Gauge MKM-571-B: Low-pressure compressed air (4 bar) (arrow 3). Place probe on the top lining plate. Measurement value: 1.14 to 1.68 mm. Measure piston stroke of multi-disc brake B1 with Dial Gauge MKM-571-B: Low-pressure compressed air (4 bar) (arrow 4). Place probe on the top lining plate. Measurement value: 0.76 to 1.44 mm AF 20 / 1.42 to 2.18 mm (AF 22) | 
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