Engine cooling,  OM617

Reconditioning of coolant pump



20—220 Reconditioning of coolant pump


Self-made tools


Spacing plate b = 2 mm
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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
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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.
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4 Press in new compact bearing flush with bearing housing by means of a tube positioned against outer race.
Do not press against coolant pump shaft.


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.
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6 Coat O-ring on counterring with brake cylinder paste and push with chamfered side (arrow) into thoroughly cleaned impeller.
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120 -10863


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.
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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.
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20.8-220/3 F 2