Clark-hurth 125A Parts Catalog – Factory Parts Breakdown for the Series II Tractor Shovel

I’ve been wrenching on heavy equipment longer than some of you have been alive. When I open a parts catalog for a Clark-hurth 125A Parts Catalog, I expect to see the exact part numbers, the correct hydraulic system layout, and brake assembly breakdowns that match what’s on the shop floor. This one delivers – 160 pages of factory-original content from Clark Equipment Company’s Construction Machinery Division. No reprints, no redrawn illustrations.

Look at the table of contents: Accelerator Pedal & Linkage – Cummins (page 22), Accelerator Pedal & Linkage – G.M. (page 23). That tells you right away the manual covers both engine variants. Air Cleaner Assembly, Brake Assembly – Front and Rear, Boom Cylinder Assembly, Bucket Cylinder Assembly. Every cylinder on this machine is documented with a part number and diagram. The brake system gets four separate sections: Controls (page 55), Lines – Cummins (page 57), Lines – G.M. (page 59), Power Cluster (page 62), Wheel Cylinder (page 61). That’s the kind of depth you need when a customer is waiting and you can’t afford to order the wrong wheel cylinder.

Cylinder Assemblies: Boom, Bucket, and Steering

Hydraulic cylinders are the money-makers on a loader. The catalog lists Boom Cylinder Assembly on page 82, Bucket Cylinder Assembly on page 83, and Steering Cylinder on page 70. Each has an exploded view with callouts. If you’re rebuilding a boom cylinder, you can match seals and pistons to the factory drawing. You don’t guess a rod diameter – you look it up. Part numbers are right there, and Clark provides the clip chart on pages 97 and 99 for quick cross-reference of clip sizes used in hydraulic lines.

I’ve wasted billable hours on aftermarket catalogs where the illustration doesn’t match the actual part. This one uses the original Clark engineering drawings. The Bucket & Boom Hydraulic System occupies pages 79 and 80, and the Control Valve Assembly is on page 85. If you’re swapping a spool or a relief valve, you need those pages open on the bench.

Brake System: From Power Cluster to Wheel Cylinder

Brakes on a 125A are air-assisted. The manual covers the Brake Power Cluster (page 62) – the unit that houses the air-hydraulic intensifier. Brake Assembly – Front (page 60) and Rear (page 60) are separate sections. Brake Wheel Cylinder (page 61) gives you the rebuild kit part number. Brake Controls (page 55) diagrams the pedal linkage and valve. Air Pressure Sender Unit and Air Reservoir are on pages 57 and 59. If you’ve ever had a brake drag because the wrong return spring was installed, you’ll appreciate that the catalog lists spring specs by part number.

Aftermarket catalogs often combine front and rear brakes into one generic illustration. Clark separates them. Why? Because the rear drive steer axle (page 47) has a different brake configuration than the front drive axle (page 45). You need to know that before you order shoes.

Engine Controls and Accessories – Cummins vs. G.M.

Two engine options: Cummins and G.M. The catalog splits engine-related sections accordingly. Accelerator Pedal and Linkage for Cummins on page 22, for G.M. on page 23. Air Cleaner Assembly for Cummins on pages 13 and 15, for G.M. on page 17. Air Cleaner Connections for Cummins on pages 13 and 14, for G.M. on page 16. Even the Engine By-Pass Oil Filter – listed for Cummins on page 19. If you’re trying to order a filter head gasket for the G.M. engine, the manual tells you exactly which parts differ. That level of specificity is why I trust OEM documentation over third-party compilations. Internal Combustion Engine isn’t just theory – it’s part identification that keeps the loader running.

Hydraulic System: Bucket, Boom, and Leveling

Pages 79-80 lay out the Bucket & Boom Hydraulic System. The Bucket & Boom Hydraulic Pump is on page 76. The Bucket Leveling Hydraulic System (page 77) covers the master cylinder and circuit – this is critical for keeping the bucket level throughout the lift cycle. Bucket Leveling Master Cylinder on page 81. If a machine has a drooping bucket, you’ll be referencing those pages to find the leveling valve linkage. The Boom Cylinder Assembly (page 82) and Bucket Cylinder Assembly (page 83) list all seals and bearings. The Control Valve Assembly – Bucket & Boom (page 85) shows the spool sections and relief cartridge.

I’ve seen guys try to disassemble a bucket control valve without the parts breakdown and lose a detent ball. This manual gives you the exploded view so you know exactly how many balls and springs go where. When you order the rebuild kit, you have the part numbers from the catalog. No guesswork.

Axle Assemblies and Differentials – Front and Rear

Front Drive Axle (page 45) and Rear Drive Steer Axle (page 47) are separate sections. Each includes the Differential & Carrier Assembly – Front on page 49, Rear on page 51. Axle Mounting Parts (page 4), Axle Tie Rod (page 54). The Cradle for rear axle is also on page 4. If you’re replacing a ring and pinion, you need the shimming specs from the differential section. The parts catalog doesn’t give you gear setup procedures – that’s in the service manual – but it does give you the exact bearing and shim part numbers. That saves time when calling the parts counter.

Pages 37-38 cover the Converter Assembly, page 40 the Converter Charging Pump. The Transmission Oil Dipstick is on page 43. All these are linked to the drivetrain. For a complete drivetrain rebuild, you’ll also want the related manual: Clark Michigan 125A Tractor Shovel Parts Manual No. 1410 and Clark 125A Parts Manual Tractor Shovel. For other Clark-hurth models, check Clark-hurth L320 1991 Parts Catalog – 690 Pages OEM Specs.

Audience Fit: Who Should Buy This Parts Catalog?

If you own or work on a Clark-hurth 125A Tractor Shovel Series II (G.M. serial 3FG101-5FG999 or Cummins serial 3FC101-6FC140), this catalog is for you. It’s built for shop owners who need fast part identification. It’s for field mechanics who carry a tablet and want to confirm a part number before making a trip to the dealer. It’s for DIY operators who want to order the right brake wheel cylinder without pulling the drum first. Automotive Industry Overview may cover general trends, but this catalog covers the specific parts that keep your loader digging.

Source Validity: OEM vs. Aftermarket

This is a genuine Clark Equipment Company publication – Parts Manual No. 167042. The cover says “Printed in U.S.A.” The index on page 3 lists every section. Aftermarket catalogs often combine multiple models into one confusing booklet. Clark keeps the 125A Series II separate. The part numbers are Clark numbers, not generic substitutions. I don’t trust aftermarket manuals for heavy equipment because they frequently omit the serial number breaks or mix up metric and SAE threads. This catalog shows machine serial numbers clearly – check your loader’s serial before ordering. That’s how you avoid returns.

FAQ

Does this manual cover both Cummins and G.M. engine versions?

Yes. The catalog lists separate sections for Accelerator Pedal, Air Cleaner, Brake Lines, and other systems for each engine. Pages 22-23, 13-17, and 57-59 are split by engine.

What kind of torque values are included?

This is a parts catalog, not a service manual. Torque specs are not listed. You’ll find part numbers, exploded views, and quantities. For torque values, you need the corresponding Clark service manual.

Can I use this to order piston seals for the boom cylinder?

Yes. The Boom Cylinder Assembly on page 82 shows each component with a part number. Find the seal kit number and order it. No need to measure old seals.

How many pages is the PDF and what format?

160 pages in PDF format, scanned from the original paper catalog. The file is searchable and includes bookmarks for each page.

Stop wasting time on generic parts catalogs that don’t match your machine. Get the factory breakdown that Clark Equipment Company issued for the 125A Series II. You’ll find the exact part numbers, correct hydraulic routing, and brake system components that keep your loader productive. Download the Factory Manual and put it on your shop tablet or print the pages you need.