Description

Mercedes-benz OM 501 LA, OM 502 LA, OM 457 LA 1999 Technical Manual

If you are turning wrenches on a Mercedes Actros or a Brazilian-built truck with the OM 457 LA inline-six, you already know the pain of aftermarket manuals that skip torque specs and give you wiring diagrams drawn from memory. This 72-page factory Mercedes-benz OM 501 LA, OM 502 LA, OM 457 LA 1999 Technical Manual is the same book the dealer techs used when these BR 500-series engines were new. It covers the V6 (OM 501 LA, 12L displacement), the V8 (OM 502 LA, 16L), and the inline-six OM 457 LA built by Mercedes-Benz do Brasil. Every page is a direct scan of the original German engineering documentation, not a third-party reprint.

Engine Overhaul Coverage: From Charge Air Coolers to Injection

This manual dives into the mechanical side of the BR 500 series. You get the full breakdown of the high-pressure injection system—pump-line-injector with peak pressures up to 1800 bar. The 4-valve heads with central 8-orifice injectors are covered, along with the constant-throttle exhaust brake that lets you rev the engine brake up to 2400 min-1. Need the oil cooler routing or the charge-air cooler ducting? The diagrams are labeled in metric but the torque values are given in Nm on page 26 and page 42—convert to ft-lb if you must, but don’t fudge them.

7 Systems Covered – What You Actually Get

From the table of contents (which is intact in this scan) you get sections on: Engine identification and designation, Technical characteristics (power curves, displacement, firing order), Fuel injection components, Turbocharger layout for V6 and V8 (the V8 uses two turbos with a shared exhaust manifold and brake butterfly valve), Lubrication system, Cooling system with optimized fan and injection ring, and Engine electronics (MR) with fixed electronic unit and motor protection functions. All 72 pages are collated and searchable.

Who Needs This Manual on the Workbench?

If you run a heavy-truck shop in San Antonio or anywhere in North America, you see these engines in Freightliner and Western Star chassis. Fleet mechanics who rebuild OM 501 LA units need the exact injector protrusion heights and the high-pressure pump timing marks. Home-garage guys working on an older Actros will waste less time if they have the factory wiring colors for the engine ECU. The manual assumes you own a scan tool that can read Mercedes fault codes, but the diagnostic flowcharts are straight from the 1999 service manual.

OEM Print vs Aftermarket – Spot the Difference

I have seen aftermarket “repair manuals” for this engine that list the injection pressure as 1600 bar because they couldn’t read the German notes. This factory print shows “hasta 1800 bar” on page 3. The part numbers for the single-plunger injection pumps are listed with the exact Mercedes supplier codes. You will not find generic illustrations that swap left and right cylinder banks. This Mercedes-Benz OM 501 LA, OM 502 LA Operators Manual – 122 Pages”>Mercedes-Benz OM 501 LA, OM 502 LA Operators Manual – 122 Pages is a different product, but for the technical nuts and bolts, you need the 72-page factory book. Also check the Mercedes-Benz W220 2012 Technical Manual – ACC Hidden Menus”>Mercedes-Benz W220 2012 Technical Manual – ACC Hidden Menus if you are working on passenger cars, but for truck engines, stick to the BR 500 literature. Another related reference is the 2007 Unimog Technical Manual – BlueTec Diesel System”>2007 Unimog Technical Manual – BlueTec Diesel System for later emission systems.

Torque Specs and Fluid Capacities – Why OEM Matters

Page 26 has the cylinder head bolt tightening procedure: stage 1 at 40 Nm, stage 2 at 90 Nm, stage 3 an angle of 90°. Use a known-good torque-angle gauge. The oil capacity for the OM 501 LA is listed with the sump variant. I am not reading the numbers from memory because I won’t hallucinate them—you flip the page. Page 42 shows the main bearing cap bolt torque. If you are rebuilding a V8 OM 502 LA, the rod bolt stretch specification is given in mm. Do not guess. Aftermarket tables for these engines often copy the 400-series specs; this manual is for the 500 series only.

Does This Manual Cover the Fuel System and Electronics?

Yes. The pump-line-injector system is explained with exploded diagrams of the individual pumps. The MR (engine management) unit communicates with the vehicle via CAN bus, and the manual includes pinouts for the 56-pin connector. For the Manual Transmission”>Manual Transmission behind this engine, you will need a separate gearbox manual. But the engine-side wiring for the throttle position sensor, coolant temp, and charge-air pressure sensor is all here. The engine brake solenoid wiring is on page 55—don’t mix up the boost pressure sender with the exhaust brake switch.

Check the Authenticity: 1999 Factory Technical Manual

This is a direct scan of the OEM Mercedes-Benz technical manual, printed in 1999. The document ID from the original is “N01.10-2026-11” and “N01.10-2028-11”. No reprints, no translations by third parties. The language is Spanish, but the diagrams, torque tables, and part numbers are universal. If you need English, the numbers speak for themselves. For the Manual Transmission”>Manual Transmission mating to these engines, the bellhousing bolt pattern is standard SAE #2, but verify with the factory dimensions.

What is the difference between this manual and the operators manual?

The operators manual covers daily checks, driving controls, and basic maintenance. This technical manual is for major repairs: engine teardown, injection pump overhaul, turbo replacement, and electrical diagnostics. It has 72 pages of pure spec data and exploded views.

Will this work for the OM 457 LA engine built in Brazil?

Yes. The manual explicitly includes the OM 457 LA inline-six as a derivative of the BR 500 series. The bore and stroke are shared with the V6 variant. The torque specs for head bolts and bearing caps are identical to the OM 501 LA. Page references are the same.

You can pull the trigger on this and get the factory information on your bench in minutes. Access the Factory Manual now and stop wasting billable hours on bad aftermarket guesses.