Description

Koehring 6644-7 1991 Parts Catalog

If you’ve ever ordered a fuel line for a Koehring 6644-7 and ended up with something that bolts to a different machine, you know the headache. This 1991 Parts Catalog kills that guesswork. It’s 129 pages of factory-verified part numbers, group layouts, and exploded views – not some aftermarket reprint that swaps out a bearing without telling you. Koehring Cranes & Excavators lithographed this in the USA (Part No. 12261-159, revised 11-91). Every number inside matches what the assembly line used.

Page 2 lays out the entire parts group structure. You get group numbers for the Engine (Group 14), the crawler and carbody (Group 2), the swing system (Group 22), and the hydraulic system. No flipping through a generic index to find what might fit. The alphabetical index on page 3 runs from Accumulator to Swivel, with exact page references. Need the fuel filter? Page 14.1. Boom cylinder seals? Page 36.6. That kind of directness is why I keep one of these on the bench instead of a third-party CD.

Engine Group Coverage: Upper Engine and Fuel System

The Upper Engine group (Group 14) is where you’ll find the block, the ether valve, the exhaust assembly, and all the filters – engine oil, fuel, and air cleaner. Group 12 covers the Upper Structure including the Fuel tank and turntable. The fuel piping diagram (14.7) shows every tube, clamp, and fitting. If you’re chasing a fuel leak on a 6644-7, you don’t need a manual that says “fuel line – see dealer.” You need the factory drawing that gives you part number 12261-whatever and tells you which O-ring goes where. This catalog does that. It also lists the throttle control cable and the mini-throttle cylinder, both common failure points on these machines. Automotive Industry Overview [LINK_ID_EXT_0] might be interesting background, but it won’t help you get a 6644-7 running again.

Crawler & Carbody – Group 2 Overview

Track chains, front idler, lower rollers, upper carrier rollers, and the carbody itself – Group 2 lays it out. You get the track guide (1.1), the crawler assembly with idler adjust cylinder (1.2), and the side frames (1.1). The alphabetical index shows “CHAIN, TRACK” on page 1.3. When you’re rebuilding a set of rails, having the exact Koehring part number for the chain pitch and roller spacing keeps you from ordering the wrong set. Aftermarket cross-references often lump all 60-ton excavators together. This catalog doesn’t.

Electrical System: 33 Group – Harnesses and Switches

Group 33 covers the electrical system: main harness (33.3), engine harness (14.6), console harness (33.3), battery relay, relays, switches for engine oil pressure, engine temp, suction pressure, swing pressure, and the thermostat switch. Also the mechatro controller and the magnetic sensor. The “CONTROLS, SWITCHES, GAUGES” listing on page 33.5 is your map for troubleshooting a no-start or a dead panel. If you’re wiring in a new floodlight or horn (Group 34), the parts pages show the correct gauge and connectors. Automotive Industry Overview [LINK_ID_EXT_1] won’t tell you which relay your 6644-7 uses. This catalog will.

Hydraulic System Breakdown: Pumps, Valves, and Swing Motor

The hydraulic system is spread across several groups: main hydraulic pump (24.3), pump drive case (24.1), swing motor (22.3), swing drive gear box (22.3), rotary manifold (12.2), pilot control valves (28.3), and all the plumbing for attachment, cooling, travel, and return. The “HYDRAULICS, PRESSURE” section on page 25.5 lists the pressure relief parts. Need the O-ring for the main valve assembly? Group 25.10 covers the valve body. The alphabetical index even gives you a separate entry for “O-RINGS” (page 25.3). This level of detail means you can order seals before you pull the machine apart, instead of waiting a week because the aftermarket catalog had the wrong bore size.

Why a 1991 Factory Parts Catalog Beats Aftermarket Lists

Aftermarket parts catalogs often renumber Koehring parts into their own system. Then you’re cross-referencing a cross-reference. This document is the original Koehring lithograph – not a copy, not a scan of a scan. The group numbers (2, 12, 13, 14, 15, 22, 24, etc.) match the factory parts page blocks. The alphabetical index was built by Koehring engineers, not a data entry team. If you’ve ever ordered a “counterbalance valve” for a 6644-7 and got something that only fits a Deere, you understand why OEM documentation matters. This catalog also includes the attachment options for clam and dragline (Group 46) and the excavator attachment (Group 36). No guesswork.

Does this catalog include part numbers for the engine?

Yes. Group 14 lists every part for the upper engine, including gaskets and the ether valve.

How do I find the correct fuel filter part number for my 6644-7?

Turn to the alphabetical index on page 3, locate “FILTER, FUEL” – it points you to page 14.1. That page shows the fuel filter assembly with the Koehring part number, the canister, and the gasket. The same page also lists the engine oil filter and the return/suction filter group. Using this index, you can find the exact part without flipping through every group. The index covers over 250 entries from Accumulator to Swivel, each with a specific page. If you’ve been burning time on part-supplier lookups that don’t know the 6644-7, this catalog is your shortcut.

Stop wasting time on aftermarket cross-reference books and generic parts lists. This is the documentation that Koehring printed for dealers and shops. Access the Factory Manual from AutoRepairManuals and get the exact part numbers Koehring intended for your 6644-7 hydraulic excavator.

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