Oil pumps - oil pipes & filters
TD engines up to engine No TD2/14423 used a slightly modified version of the oil pump and filter system used on the TC. The differences is that the oil pipe from the pump to the filter is connected to the pump by a banjo bolt to the top of the cover rather than by a two bolt flange to the top of the body. Later engines from TD2/14424 and all TF’s were fitted with an oil pump having an integral oil filter thus preventing the possibility of fractured oil pipes and leaks from the any washers on the earlier system. The internal parts of the two pumps are the same. This pump was fitted with either a Purcolator or a Tecalemit oil filter, these have different bowls, centre bolts, filter pressure plates etc., but both accept the same oil filter. Various improvements were made to the later pump during the production: at TD2/20972 the cover was fitted with a priming plug, at TD2/26635 the body was modified to retain it prime and at TF31263 the pump was modified to be self priming.
Priming of the oil Pump: There are two specific ways this can be done. One is by removing the main cap held on by the long 3/16" bolt and packing the gears with a petroleum jelly (vaseline) or secondly, by removing the brass plug adjacent to the cylinder block on the top of the oil pump and using a pump oil can to prime both the gallery and the oil pump itself. This will normally solve any problems. We would recommend that the oil pressure be raised prior to starting the engine and this can be satisfactorily accomplished by removing the sparking plug and the turning the engine by hand of by starter motor. It is worth noting that the clearances within the oil pump are of particular significance and the end ply between the rotors and the housing should be not more than one or two thou. It may be necessary to machine the main body of the oil pump to achieve this clearance and not just to face the cap as so many other manuals suggest. A further point worth noting is that the oil pump gear idler shaft is regularly knocked while the block is stripped and in machine shops and a misalignment of one or two thou can cause the gear to effectively screw out of its housing and cut into either the body of the cap. This clearly is not acceptable and care must be taken on assembly to ensure that the shaft is absolutely at right angles to the block. Make sure that the gears are running square to each other and not at an angle.
Final point is to ensure that the oil pressure relief valve and its ball are properly seating and that the proper spring is fitted. This should ensure a trouble free start up with oil pressure
