Description

Koehring 6633L, 6638L 1985 Parts Catalog – OEM Factory Parts Reference

If you’ve ever tried to order a hose for a Koehring 6633L or 6638L and got the wrong part because the aftermarket cross-reference was garbage, you know the pain. This 15-page Koehring 6633L, 6638L 1985 Parts Catalog is the OEM document that Koehring printed in September 1985. It covers the hydraulic system – swing, traction, and attachment – with factory part numbers, discontinued part alerts, and supersession instructions. It won’t tell you how to rebuild the pump, but it will tell you exactly which capscrew and cushion to order. That saves a week of downtime right there.

What This Parts Catalog Covers (And What It Doesn’t)

This is a parts catalog, not a service manual. You won’t find torque specs or step-by-step rebuild procedures here. What you get is a grouped parts breakdown: Group 25 covers the hydraulic swing and traction system, with separate pages for the attachment circuit. Every item is listed with a reference number, Koehring part number, description, and quantity. For example, on page 25.11A you’ll see traction piping specific to the 6638L – elbows, hoses, straps, and a pipe spacer. The catalog also flags discontinued parts: “DISCONTINUED PART! REFER TO NUMERICAL PARTS LIST FOR REPLACEMENT PART(S).” That alone is worth the price if you’re hunting a NOS part that’s been superseded.

Hydraulic System: Swing, Traction, and Attachment (Group 25)

Group 25 is the core of this catalog. The swing and traction pages show valves, solenoids, flow control valves, hose assemblies, and mounting hardware. The attachment section (page 25.11B) includes a complete valve assembly with a breakdown of inlet sections, plunger sections, relief valves, spools, and seals. If you need a replacement for item 6 (a relief valve, 2000 psi) or the O-ring under the spool end, the part number is right there. The catalog also notes when parts on later pages supersede earlier ones – “PARTS SHOWN SUPERSEDE RESPECTIVE PARTS ON PAGES 25.10 & 25.11.” That cross-reference keeps you from ordering obsolete stock.

Page 25.11A – Traction Piping for the 6638L

Look at page 25.11A. It’s a dedicated page for traction piping on the 6638L model only. You get part numbers like 708 7431-102 for a hose and 445V2406 for a strap. The note says “SEE PAGE 1.12A FOR TRACTION PIPING” – though that page isn’t included in this 15-page catalog (the full catalog is larger). The point is, every fitting and bracket is identified. If you’re trying to replace a crushed hose or a snapped strap, this page eliminates the guesswork. No more walking the hydraulic line with a tape measure and hoping the parts house has something close.

Discontinued Parts and Supersession – Why OEM Matters

Aftermarket catalogs often skip discontinued part notes or guess the replacement. This manual prints “DISCONTINUED PART!” in bold right on the page. It then tells you to check the numerical parts list for the replacement. The OCR excerpt shows five separate discontinued items on page 25.11B alone. If you buy a third-party reprint, those notes might be blurred or omitted. With the OEM scan, you see exactly what Koehring engineers intended. That’s the difference between ordering a part that fits and ordering a paperweight. Check the related Koehring 6633L, 6638L 1985 Parts Catalog – OEM Supplement for any later revisions if your serial number falls outside the range covered by this issue.

Ordering Parts the Right Way

Every page of this catalog carries a mandatory instruction: “WHEN ORDERING PARTS, SPECIFY MODEL NUMBER, SERIAL NUMBER AND DESCRIPTION OF PART REQUIRED.” That’s not a suggestion – it’s how Koehring designed their parts system. If you call a dealer and rattle off a part number without the serial number, you may get a superseded revision that doesn’t match your machine’s build date. This catalog gives you the part number and the proper format for ordering. Pair it with the Koehring 6633L, 6638L 1986 Parts Catalog – OEM Factory Manual if your machine was built after September 1985, and keep the Koehring T-S44, 644 1974 Parts Catalog – Factory OEM Parts Reference on hand for older Koehring models if you’re mixing fleets.

Who Needs This Catalog?

If you maintain a Koehring 6633L or 6638L, this catalog belongs in your toolbox. Home-garage guys who run a small excavator or crane will use it to identify every hydraulic fitting without pulling the machine apart first. Professional mechanics bill by the hour – spending 20 minutes with this catalog to cross-reference a discontinued part beats two hours of trial-and-error with universal hoses. Beginners should understand that this is not a how-to manual; it’s a parts reference. But if you’re tearing into a hydraulic swivel and need to know which O-ring goes where, the exploded diagrams and part numbers are your safety net. For broader context on the industry and why OEM documentation remains critical, read the Automotive Industry Overview on Wikipedia. You can also browse the Automotive Industry Overview for historical background on equipment standardization.

FAQ

Is this the full service manual for the 6633L and 6638L?

No. It is a parts catalog – 15 pages covering hydraulic system parts only. For repair procedures you need the separate service manual.

Does this catalog include electrical or engine components?

No. Group 25 is exclusively hydraulic. The engine, drivetrain, and electrical systems are in other groups that are not part of this 15-page document. If you need those, look for the complete Koehring master parts manual.

How do I verify a part number matches my machine’s serial number?

Call your Koehring dealer with the part number and your machine’s serial number. The catalog states that parts may supersede based on serial number range. The discontinued part notes also direct you to the numerical parts list for the correct replacement. If you don’t have the numerical list (not included here), the dealer can pull it from their system.

Can I use this catalog to order parts for a 6633L built in 1987?

This edition was issued in September 1985. Later production may have different part numbers for the same hydraulic components. Check the 1986 supplement [LINK_ID_REL_1] or contact Koehring with your serial number before ordering.

You’ve seen the data – factory part numbers, discontinued part alerts, and clean hydraulic diagrams. That’s what you get when you access the Factory Manual. Click the button below to secure your copy and stop wasting time on aftermarket guesswork.