Description
This is the only part in our current Caterpillar group that Caterpillar’s own literature places in the cooling fan circuit, and the wording leaves nothing to interpret. The parts book records 162-0770 as PUMP GP-PISTON -HYDRAULIC FAN inside the group 161-9693 PUMP & MTG GP-HYDRAULIC FAN, with a control valve catalogued as pressure and flow compensator for hydraulic fan duty and a rotating group named for the hydraulic oil cooling fan.
Applicabilité
CAT 966G from prefix 3ZS 00001 and 972G at 4WW 00001 to 856 with the Cat 3306 engine, plus the further G-series prefixes in Cat’s applicability data (7LS, 9RS, 1EW, 3SW, 3PW, 6AW, HDH, 8XW, AAH, AAW, 9GW). The fan motor it feeds is 161-8919, on its own page. Cat publishes no displacement, pressure or flow figure for 162-0770, so none is quoted here.
The trap: G-series and G II are not the same fan pump
This is the most expensive mistake available on the part. The 966G II and 972G II Series II loaders, on the 3176 and 3176C engines, use a different fan pump group recorded as 184-5400 PUMP & MTG GP-HYDRAULIC FAN. A Series II machine does not take 162-0770, and the housings are similar enough for a parts desk to be talked into it from a photograph. Read the model designation on your plate: if it says 966G II, or the serial prefix is ANT, ANZ, AXJ, AWY, AWZ or AWL, quote against the Series II group instead.
Diagnosis
A fan pump losing displacement produces the same complaint as a plugged core or a tired motor: heat under load that improves on the move. Clean the cores, check oil level and the return filter, measure delivery pressure and flow with the oil hot, then confirm the control signal before condemning the pump. The tests are set out in our guide de diagnostic des pompes de ventilateur hydrauliques et diagnostic et réglage du régulateur.
Montage
Match shaft spline, pilot, flange, port positions and control orientation against the removed pump. Prime the casing with clean oil before cranking. Change the return filter element and clear the suction strainer, targeting ISO 4406 18/16/13. Keep the case drain unrestricted to tank. Prove full fan speed under thermal load and log both temperatures.
Commande
Minimum order one piece. New aftermarket units carry a three to six month warranty as stated on your proforma invoice. Bench tested, photographed against your order before the case closes, delivery 5 to 8 working days from payment subject to stock. Related: 161-8919 fan motor et la Caterpillar fan drive range.
