Important Notes

When repairing the tandem pump, the repair kit of the respective manufacturer must be used. Scrupulous cleanliness should be observed when performing any work on the tandem pump. The work should be performed on a plastic base, if possible; chamois leathers are particularly suitable.
A strict standard should be applied when examining steering parts.

If the vehicle you are servicing is not covered by one of the following two notes, proceed to "Work steps". Work Steps If you are unsure what model (chassis) number you are working on see Application and ID. Application and ID

NOTE 1:
This note (below) applies only to models 129.076, 140.056/057. Perform the steps below in lieu of the first three steps found in "Work Steps".

Disassembling:

The tandem pump (1) for engine 120 has an expansion reservoir for equalizing the oil reservoir (35) on the pump housing which is located between the coolant thermostat and the intake pipe.




An oil dipstick (36a) with min. and max. markings for the oil level check is located on the end cover of the expansion reservoir (36).




Unscrew the four bolts (35a) from the oil reservoir (35) and remove reservoir. Check O-ring (2g), replace if required. Work steps numbers 1-3 in "Work Steps" are omitted.

NOTE 2:
This note (below) applies only to models 129.066/067, 140.04/050/051. Perform the steps below in lieu of the first three steps found in "Work Steps".

Disassembling:




On this model the oil reservoir (35) is attached to a support (1a) which is screwed to the tandem pump (1).




Loosen hose clamp, disconnect hose (arrow) and set aside. Unscrew bolts (46) and remove tandem pump (1) from support (1a).




Unscrew bolts (arrow, 4 bolts). Remove end cover (2k), check O-ring (2g), replace if required. Work steps numbers 1-3 in "Work Steps" are omitted.