Description

Hyster H70, H110, S70, S120, H135 Service Manual – Factory Specs You Can Trust

You got a Hyster forklift in the bay with a Perkins diesel that won’t idle right, or you’re staring at a valve cover you don’t want to warp because some aftermarket PDF told you 18 ft-lb when it should be 22. I’ve been there. This manual is the real deal – 132 pages of Hyster’s own service procedure for the H70, H110, S70, S120, and H135 models. Not a reprint, not a scan of a scan. Original OEM content from the factory that built the truck.

Before you reach for that torque wrench, you need to understand what you’re working on. The manual starts with Perkins Diesel Engines – specifically the 1004-42 (AR), 1006-60 (YG), and 1006-60T (YH) blocks. Engine serial number codes, data tables, and safety rules that’ll keep your fingers attached. Page 2 lists the safety precautions: disconnect battery ground on internal combustion trucks, use lifting mechanisms for heavy parts, and never skip the DO NOT OPERATE tag. I’ve seen guys lose a hand because they ignored that. Don’t be that guy.

Cylinder Head Assembly: Valve Cover to Valve Seats

If you’re pulling the head on one of these, you need the sequence. The manual walks through valve cover removal and install, rocker arm assembly (disassemble, inspect, reassemble), and valve clearance adjustments for both four-cylinder and six-cylinder engines. It’s not a guessing game – the gap is specified by engine code. You’ll also find the procedure for valve springs, valve guides (inspect, remove, install), and cylinder head and valve seats including repair and installing new seats. Every step has the torque value and the order. Don’t skip the inspection step for the valve guides – I’ve seen a loose guide wreck a new seat in 50 hours.

Piston and Connecting Rod Assemblies – Get the Right Parts

Wrist pins, ring gaps, bearing clearances – this section covers rod bearings (remove, install), piston and connecting rod assembly (with a service note I’ve never seen in aftermarket garbage), and piston rings. There’s a specific section called How to Select Correct Replacements inside the “Piston and Connecting Rod” chapter. If you’re ordering parts online and the counter guy asks for the engine code, you better have this manual open. Also covers piston cooling jets – something a lot of DIYers forget to check. A clogged jet kills a piston in short order.

Crankshaft, Timing Case, and Lubrication – 3 Critical Systems

The Crankshaft Assembly Repair chapter covers removal, inspection, and installation of the crankshaft itself, plus main bearings, thrust washers (with crankshaft axial movement check), flywheel and ring gear replacement, and rear oil seal replacement. The Timing Case and Timing Gears Repair goes into camshaft gear removal, idler gear and hub, fuel injection pump gear, and the Bendix air compressor drive. If your timing is off, check the manual’s Engine Timing section – it shows how to set number one piston to TDC on compression stroke and verify valve timing. Don’t trust a paint mark on a used gear.

Lubrication system: oil filter replacement, filter head removal, oil sump, oil pump (remove, inspect, install), relief valve, and idler gear shaft replacement. There are alternative procedures for four-cylinder and six-cylinder engines – the manual tells you which one applies.

Fuel system repair includes injection pump removal and timing adjustment, fuel injector inspection, fuel pump disassembly and test, and the proper air removal procedure. Cooling system covers thermostat test, coolant pump removal and assembly, fan drive, and oil cooler service. If you’re working on an S70 or S120, pay attention to the engine code suffixes – they’re different from the H70/H110.

Why Factory Manuals Beat Aftermarket – Every Time

I’ve got a stack of aftermarket manuals that quote the wrong torque for the cylinder head bolts on a Perkins 1006. This manual came from Hyster. The valve clearance specs, the cylinder bore dimensions, the engine data – all verified by the manufacturer. The Service Manual is 132 pages of procedures you can trust. No vague “tighten securely” nonsense. If the spec says 88 ft-lb, that’s what it says. And you’ll find it on the page for the specific engine variant you have. Look for the engine serial number code on your data plate, then cross-reference in the Description chapter. That’s how you avoid buying the wrong gasket set.

For more related factory documentation, check out Hyster H70-H110XL Parts Catalog 1999, Hyster S120, S80 Technical Manual – 16 Pages of Factory Specs, and Hyster A513 A514 A613 A614 A702 2014 Service Manual. If you need background on how a manual transmission works on other equipment, see Manual Transmission and Manual Transmission for general principles.

Frequently Asked Questions

Does this manual cover the H135 model?

Yes. The cover explicitly lists H135. The engine section includes the 1006-60T (YH) turbo diesel used in the H135. All procedures apply.

What torque values are listed for the cylinder head?

Final torque is specified in the Cylinder Head Assembly Install section. It depends on the engine variant – AR, YG, or YH. The manual gives the sequence and the angle-tighten steps. Never reuse head bolts. The book tells you why.

Is this a reprint or a factory original?

Factory original. Hyster part number 1455747. Not a scan, not a third-party copy. You get the same manual the dealer techs used.

How do I adjust valve clearance on a Perkins 1006-60 (six-cylinder)?

You’ll find the procedure under Valve Clearance Adjustments – Six-Cylinder Engines. It lists the intake and exhaust gaps, the firing order, and the cold adjustment method. Water temperature matters. The manual specifies below 122°F.

Stop chasing suspect specs on forums. Access the Factory Manual and get the procedure that matches the truck on your lift. Your torque wrench will thank you.