Reconditioning of coolant pump

Spacing plate b = 2 mm

Pressing-in sleeve

1    Fan hub

2   Coolant pump shaft with compact bearing

3   Bearing housing

5   Slide ring seal

6   Counterring

7   O-ring

8   Impeller

a    22.8—23.2 mm

b   2 mm

c    Vent holes

1    Support bearing housing with pertinent tubing and press out coolant pump shaft by means of a mandrel.

2    Knock sliding ring seal out of bearing housing.

20.8-220/1 F 2

3 Remove counterring from impeller.

Note: Always replace compact bearing and fan hub following disassembly.

4 Press in new compact bearing flush with bearing housing by means of a tube positioned against outer race.

5 Coat mounting bore of sliding ring seal in bearing housing slightly with sealing compound (part No. 001 989 25 20).

Press-in or knock-in sliding ring seal with pressing-in sleeve.

Support only against bearing housing and not against coolant pump shaft.

6 Coat O-ring on counterring with brake cylinder paste and push with chamfered side (arrow) into thoroughly cleaned impeller.

20.8-220/2 F 2

7   Clean sealing surfaces of counterring and sliding ring seal free of dust by means of a chamois cloth.

8   Degrease both shaft stubs and impeller in bore.

9   Press-on impeller flush with shaft while support­ing coolant pump shaft.

10 Heat fan hub on a hot plate to approx. 300 °C (annealing color dark — up to light blue).

Place heated fan hub on a recessed base. Hold spacing plate on coolant pump shaft, slip coolant pump shaft on fan hub and apply a blast of compressed air against hub. Wait for a few seconds until fan hub is firm and then cool immediately in water bath.

20.8-220/3 F 2