Description
This is the H-series counterpart to the G II pump, and it is one of the few fan units where Caterpillar states the displacement control type outright rather than leaving it to be inferred from the item name. If you are fitting a fan pump to a 950H or 962H, this is the number Cat lists.
What Caterpillar states
254-5146 is listed as a Hydraulic Fan Piston Pump, and the Chinese-language catalogue entry describes it as a variable displacement axial piston pump. The parts book item name is PUMP GP-PISTON, with variants recorded as PISTON PUMP GROUP-SLIPPER. Cat publishes physical dimensions of 8.3 in height and 10.8 in length in carbon steel, and lists the compatible models as 950H, 962H and the IT62H integrated toolcarrier. The component cross-reference is 10R-7697.
Applicability by prefix
Caterpillar’s data attaches this pump to the 950H at N1A, K5K, M1G, JAD, MXL and J5J with the Cat C7 engine, and K5K from 01000 for the Phase II builds, plus JLX with the C7.2. The 962H is covered at N4A, K6K, M3G, MAL, PCW and J6J with the C7 and SSA with the C7.2, and the IT62H at M5G with the C7.
Machine context
| Modèle | Moteur | Net power | Poids en ordre de marche | Cooling capacity |
|---|---|---|---|---|
| 950H | Cat C7 ACERT | 197 hp at 1,800 rpm | 40,435 lb | 11 gal |
| 962H | Cat C7 ACERT | 211 hp at 1,800 rpm | 42,700 lb | 11 gal |
| 966H | Cat C11 ACERT | 262 hp (195 kW) at 1,800 rpm | 52,254 lb (23,702 kg) | 10.3 gal (39 L) |
The 966H row is included because workshops routinely order across the H range, and the fan motor 161-8919 covers all of these machines even though the pumps differ. We could not find a published hydraulic relief pressure for the 966H that we would trust, so none is listed here.
Loader cooling, as Caterpillar describes it today
Cat’s own words on their current medium loader explain why a variable displacement fan pump earns its place on a wheel loader:
Electronically controlled, hydraulically driven variable speed fan adjusts to meet the varying cooling requirements of the machine. This results in a reduced average fan speed, lowering fuel consumption, noise levels, and radiator plugging.
Read the last item in that list again. Radiator plugging is treated by the manufacturer as something the fan control helps manage, which means a loader that runs its fan at low average speed is a loader whose core is doing a better job of staying open. It also means the reverse is true: a machine with a fan pump stuck at part displacement will plug its core faster, and by the time the temperature gauge is noticed, the cost is no longer just the pump.
On the largest Cat loaders the same principle is stated as standard equipment: the 988 lists a hydraulically driven demand fan, with high ambient cooling software offered as an option.
Diagnosis order for an H-series loader
- Wash the core faces and re-measure temperatures at low and high idle. Do this before anything else.
- Check the hydraulic oil level, the condition of the return filter and the suction strainer. Starvation is mistaken for pump wear constantly.
- Measure delivery pressure and flow at the pump with oil at working temperature. Our guide de diagnostic des pompes de ventilateur hydrauliques covers the setup.
- Confirm the control is receiving its command. See diagnostic et réglage du régulateur.
- Then judge the pump itself, and inspect what drives it with the transfer case failure guide if the machine has already lost a unit.
Montage
Match shaft spline, pilot diameter, flange, port positions and control orientation against the removed pump. Prime the casing with clean oil before cranking. Fit a new return filter element and clear the suction strainer, holding cleanliness around ISO 4406 18/16/13 in line with Bosch Rexroth guidance for axial piston units. Keep the case drain unrestricted to tank. Prove full fan speed under thermal load and log both coolant and hydraulic oil temperatures.
Conditions
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 wooden case closes, delivery 5 to 8 working days from payment subject to stock, by sea, air or express courier. Payment by L/C, T/T, PayPal or Western Union. The G II pump that this is so often confused with is on our 191-2942 page, and the full CAT range is under Moteur de ventilateur hydraulique Caterpillar.
