Description

Leyland 38 TD, 4/98NT Service Manual – What the Factory Built This For

Ever had a job go sideways because you trusted a generic manual’s injection pump timing? That’s why you need the factory Leyland 38 TD, 4/98NT Service Manual. I’m Mike Callahan, 28-year ASE Master. I’ve seen what happens when you guess on valve clearances – bent pushrods, broken rockers. This 86-page OEM manual puts the correct specs in your hands. It covers both the 38 TD and 4/98NT engines, the same ones fitted to JCB machines. The fuel system? It gives you the bleeding procedure for the Simms Minimec and the CAV DPA pump – two different pump types that require different steps. Don’t mix them up.

Valve Clearance Adjustment: A 400-Hour Job

Section 2 of this manual is titled “Valve Clearance Adjustment.” It’s not a suggestion – it’s a scheduled maintenance item at every 400 hours. The procedure on page 2-1 tells you to stop the engine, remove the rocker cover, then turn the crankshaft until valve No. 8 is fully open. After that, check the clearance on valve No. 1 using a feeler gauge. The correct spec is in the Technical Data section. I’ve seen techs skip the sequential firing order and end up with a noisy valvetrain. This manual keeps you honest.

Fuel System Bleeding: Simms Minimec and CAV DPA

The fuel system chapter (Section 4) is split by pump type. For the Simms Minimec, the bleeding procedure starts on page 4-1. For the CAV DPA, there are two sub-sections: one for engines up to number 35216 (page 4-2) and another for engines from number 35217 onward (page 4-3). That kind of split is exactly why you need the OEM document – aftermarket manuals often ignore serial number breaks. The fuel filter, sedimenter, and lift pump are covered on pages 4-4 through 4-6. Each component has its own drain and service interval.

Safety warning: Bleeding a high-pressure injection pump requires care. Follow the procedure to avoid fuel spray injuries. Always depressurize the system first.

Lubrication Intervals – Oil and Filter

Engine oil is checked every 10 hours, drained and refilled every 200 hours. The oil filter is renewed at the same 200-hour mark. Those intervals are straight from the Routine Maintenance schedule. Page 3-1 covers the oil check, page 3-2 covers the filter. Don’t stretch the intervals – these engines run hot in JCB loaders, and dirty oil accelerates wear on the injection pump’s internal parts. If you’re also working on related equipment, check out Leyland DAF EN 55, ET 70 1996 Service Manual – OEM Factory Specs for diesel engine variations.

3 Maintenance Schedules You Need to Follow

The manual breaks service into three intervals: every 10 hours (oil level check), every 50 hours (fuel filter drain, sedimenter drain, Simms injection pump oil level check, fan belt check), and every 200 hours (oil change, filter change, pump drain and refill). At 400 hours you get valve clearance checks, fuel filter element renewal, injector cleaning, and lift pump filter gauze cleaning. These schedules keep the engine reliable. I’ve seen too many DIYers skip the 50-hour fuel sedimenter drain and then wonder why the pump starves for fuel. The Leyland DAF A-727, A-518, 4 HP 22 1992 Service Manual – OEM Specs is another good resource if you’re working on the transmission side of the drivetrain.

What Torque Values Are Listed?

Torque settings in this publication are given as ‘mean’ figures and may vary by 3% higher or lower. That’s printed in the preface. For critical fasteners like cylinder head bolts, use the exact values from Section 3 (Cylinder Head overhaul). Page 4-7 covers the Simms injection pump oil level check torque. I won’t guess a torque spec for you – that’s why you buy the manual. Understanding the engine’s interface with the Manual Transmission is essential when you’re bolting the engine back into a machine. The Manual Transmission section of your service library should be alongside this manual.

Source Authenticity: OEM vs Aftermarket

This is a genuine British Leyland publication (part number 9803/1200). It was written for JCB Distributor Service Engineers. That means it’s the same manual the factory techs used. Aftermarket manuals – the ones that reprint scanned copies of unknown origin – often transpose torque values or omit the serial number splits for the CAV DPA pump. This one has an asterisk system: revised information is marked with an asterisk, and page issue numbers are updated. You can trust the data. The Clark / Leyland 125 Series III Parts Catalog – 98 Pages helps with parts identification if you need to order seals or gaskets.

FAQ

Does this manual cover both the 38 TD and 4/98NT engines?

Yes. Unless otherwise specified, all information applies to both.

How do I adjust the valve clearances correctly?

Remove the rocker cover, turn the crankshaft until valve No. 8 is fully open (page 2-1 explains the sequence). Then check the clearance on valve No. 1 using a feeler gauge. The spec is in Technical Data. Follow the sequential firing order – don’t skip. After adjustment, torque the rocker shaft bolts to the correct specification. Many engines have been damaged by guessing this procedure. Use the factory spec – it’s not a suggestion.

Don’t let a guess cost you an engine rebuild. Access the Factory Manual and put the Leyland 38 TD, 4/98NT Service Manual on your workbench. That’s the difference between a fix and a fire.