Takeuchi TB125, TB135, TB145 Workshop Manual – OEM Factory Specs

You have a Takeuchi compact excavator on your lift and the cylinder head needs to come off. You grab a universal manual and find torque values that don’t match the bolt grade. That’s how fasteners snap and oil leaks start. This Takeuchi TB125, TB135, TB145 Workshop Manual is the factory book — 1093 pages of what the engineers wrote, not what some third-party editor guessed. I have used these books across six bays for 28 years. They keep jobs on time and out of the red.

Engine Overhaul: Disassembly and Reassembly

Section VI of this manual breaks down the TNE-series engines and the 3TNV/4TNV series. You get the full sequence from complete disassembly (section 4.1) through cylinder head work (section 4.2) and gear train removal (section 4.3). Valve seat correction and valve guide replacement are spelled out with the actual measurements and clearance specs. The reassembly order includes the torque sequence for head bolts — not a generic pattern, the sequence Takeuchi specified. I’ve seen techs skip the camshaft bushing replacement procedure (section 4.3.7) and then chase low oil pressure for days. This book gives you the bushing ID and OD tolerances so you fit it right the first time.

Fuel System and Cooling System: Factory Procedures

Fuel contamination kills injection pumps. Section 7.2 covers the entire fuel system diagram, fuel injection pump disassembly, and the Cold Start Device (C.S.D.). The cooling system section (section 6) includes the water pump components, thermostat inspection, and radiator cap inspection from section 2.6. Page 4 of the manual warns about using the correct coolant mixture — that page also lists the serial number ranges for TB125 (12510003~), TB135 (13510004~), and TB145 (14510004~). Cooling system torque values are listed in the service standards table. Don’t guess the thermostat rating; the book gives you the opening temperature.

Does This Manual Cover the Hydraulic Units?

Yes. Section IV is dedicated to hydraulic units — pumps, control valves, and cylinders. The troubleshooting section (V) links hydraulic symptoms to specific system checks. If the boom drifts or the track speed falters, the quick-reference table in section 3.2 points you to the right pressure test. The manual does not include electrical wiring diagrams beyond the basic safety circuit connections, so for harness-level diagnostics you need the Takeuchi TB125 Parts Catalog for exact connector part numbers.

1093 Pages of Factory Specifications

Every spec in this manual came from Takeuchi’s engineering department. You won’t find a single “check your local dealer for details” note. Page 5 explains the manual’s page-numbering system and revision codes — important if you ever need to confirm you’re looking at the latest update. The book covers periodic inspection intervals from initial 50 hours up to 2000 hours (section 2.2). Want the no-load maximum speed adjustment? Section 2.3. Need the compression pressure range for troubleshooting? Section 3.3. All values are in Imperial units: ft·lb, psi, and degrees Fahrenheit.

Troubleshooting: Quick Reference Table and Compression Test

Section 3 starts with preparation before troubleshooting — things like making sure the battery is fully charged and the fuel system is bled. The quick-reference table cross-references symptoms like hard starting, low power, and excessive smoke to probable causes. Then section 3.3 walks you through measuring compression pressure with a standard compression gauge. The manual lists the minimum pressure and the allowable variation between cylinders. I’ve used this table to catch a stuck ring on a TB145 that two other shops misdiagnosed as a bad injector. For deeper transmission work, the Takeuchi TB145 TB150 Technical Manual covers the undercarriage and final drives separately.

If you are working on a smaller model like the TB28FR, the Takeuchi TB28FR Workshop Manual – OEM Factory Specs for Compact Excavator shares many of the same inspection procedures but with different frame dimensions. For general powertrain theory, understanding a Manual Transmission is not the same as the hydrostatic drive in these excavators, but the manual’s hydraulic troubleshooting principles carry over. The Manual Transmission comparison is only useful for understanding gear reduction basics — this manual covers the actual pumps and motors.

Is this manual a PDF download or a printed book?

PDF download delivered instantly after purchase.

Does it cover the TB135 model specifically?

Yes — this manual covers TB125, TB135, and TB145 models. The serial number ranges are listed on page 1: TB135 starts at 13510004~. All engine, hydraulic, and chassis sections apply to all three models unless a note specifies otherwise.

What torque specs are included for the cylinder head?

Section 4.2.3 (Reassembly procedure) gives the tightening sequence and torque values for the 2-valve cylinder head. The manual also includes the final angle-tightening step if applicable. You also get torque specs for the gear train (section 4.3), main bearing caps (section 4.4), and the turbocharger mounting bolts (section 8.2.2). Every value is OEM, not aftermarket approximations. If you follow these specs, head gasket leaks are a thing of the past.

Can I print specific pages for the shop floor?

Yes. The PDF is not locked. Print sections 2.2 (inspection schedule) and 4.2 (cylinder head) and keep them in a binder. I do that for all my technicians.

Look, I’ve been doing this since the 90s. I’ve watched guys burn billable hours chasing specs that don’t exist in aftermarket books. This factory manual eliminates that waste. You get the full engine rebuild sequence, fuel and cooling system procedures, hydraulic troubleshooting, and every torque value Takeuchi expects. If you work on compact excavators, you need this on your tablet or your bench. Download the Factory Manual and stop second-guessing the numbers.