how to protect hydraulic pump excavator

Quick Answer The Hitachi ZX850-3 / ZX870-3 travel device is the complete final drive that moves the machine — hydraulic motor, parking brake and planetary reduction in one unit. It is listed under the travel device number 9251681, and its own lubricant is listed under 4636857. The assembly weighs about 1,200 kg and packs in a 100 × 100 × 70 cm case.There are two things worth unde...

Quick Answer The CAT 320GC uses the A28VO130 hydraulic pump group, listed under five order numbers — 489-3483, 531-9885, 567-9721, 593-8367 and 655-8833. It weighs about 190 kg and packs in a 77 × 67 × 75 cm case.Here is the money-saving principle in one line: on this machine, most "pump problems" are not pump problems. The 320GC uses an electronically controlled pump with intell...

Quick Answer The CAT 336 / 340 main hydraulic pump is a two-section variable-displacement axial-piston pump, supplied under two Cat order numbers — 568-3006 and 568-3007. Both belong to the same machine family, but they are not automatically interchangeable: what decides the correct one is your machine's build and serial, and above all the input spline. This pump is offered with a 13-tooth (...

Quick Answer The travel motor assembly on a Hitachi ZX200 is a two-speed axial-piston travel motor with built-in planetary reduction and a parking brake, known by the designation HMGF38DA. Choosing the right one is not a matter of picking a favourite number, because eight part numbers are commonly quoted for this one machine — 9168003, 9195451, 9234034, 9237802, 9191194, 9199841, 9190295 and...

Quick Answer The CAT 320D3 swing drive is ordered at three levels, and they are not alternatives to each other — they are three layers of the same assembly. 525-3741 is the complete swing device, 524-2647 is the swing motor, and 543-1000 is the swing reduction gearbox on its own (in fact 543-1000 sits inside 525-3741). That structure decides your whole purchase: you cannot choose a number un...

Quick Answer The main pump on a Caterpillar 336F is a variable-displacement axial-piston pump — Cat catalogues this unit as 377-4950, a "2P Series Hydraulic Pump", and the trade knows it as the SBS180. It does one job: turn engine rotation into hydraulic flow and pressure, and then vary that output continuously so the machine gets exactly the flow the operator is asking for. Understanding ho...

Quick Answer The Kawasaki K3V112DT is so common on 20-tonne excavators for one simple reason: it is the pump that most of the industry settled on at the same time. Volvo, Hyundai, Doosan, Sumitomo, Kobelco and others all bought the same Kawasaki pump for their 20-tonne machines, so the K3V112DT has the largest installed base in the class. The practical consequence for buyers is that almost every 2...

Quick Answer Every piston pump leaks a little oil internally, and that oil has to go somewhere — it drains out of the pump case through the case drain line. That is the diagnostic gift: case drain flow is internal leakage made visible and measurable. On a PC600-6, measuring case drain flow at operating temperature, at a defined operating point, tells you how worn the pump is long before the ...