Description

Voith Retarder 115 Service Manual

If you are pulling a Retarder 115 off an Actros and don’t have the factory specs, you are asking for a comeback. I have seen techs guess on the pump pressure and blow an oil seal. This manual is the one Voith shipped to dealers. 146 pages of actual procedures, not a reprint. Every torque value, every wire color, every error code is from the original Voith documentation.

What the 146 Pages Cover: From Oil Change to Electrical Connections

General section starts with Retarder data – weight, fluid capacity, operating voltage. Then the maintenance chapter walks you through oil change intervals and the special service function activation. The diagnosis section is the meat: troubleshooting diagram, layout of components, plug connections, and a full overview of error codes. You get the Electrical Connections Diagram on page 4/8 for the R 115 H. The Annex has a conversion table and a tightening torques table with Nm values for every fastener. You will need to convert those to ft-lbs if your torque wrench reads imperial. No shortcuts.

After that the repair chapter shows an overall illustration of main components – casing ventilation, silencer, heat exchanger, top and bottom oil tank covers, oil tank. Control parts covers the proportional valve, cooling-water temperature pickup, and oil temperature pickup. Every section is factory authored.

Does This Manual Cover the CAN-Bus System?

Yes. The general section includes a dedicated Vehicle CAN-Bus chapter. When the Retarder control unit talks to the rest of the truck, you need that bus architecture. Aftermarket manuals usually leave out the CAN-Bus wiring because it is too complex. This manual has the function-and-operation scheme and the bus lines laid out. If you are chasing an electrical ghost, start there.

The electrical system is not something you can shortcut. I have watched guys fry a control unit because they guessed which wire was the CAN high. Page 4/8 gives you the real connector pinouts. That alone is worth the price.

3 Critical Maintenance Procedures You Need Specs For

• Oil Change Intervals – Specified by operating hours and load. Ignore them and the retarder loses braking power.
• Checking Oil Level – The level plug location and temperature conditions are in chapter 3.2.
• Activate Service Function – You must manually run the service function to purge air after an oil change. The sequence is on page 3/12.

These are not generic steps. They are Voith’s own procedure. Miss the service function activation and the retarder will not build pressure on the first road test.

Get the Right Torque Values from the Annex

The Annex has a Tightening Torques table. Every threaded connection – heat exchanger bolts, oil tank cover, proportional valve mounting – has a specified Nm value. Do not use a generic torque chart from a third-party website. The flange bolts on the oil tank cover need 25 Nm. Go to 30 Nm and you crack the plastic. The Annex also includes a conversion table to inch-pounds if you need it. I keep a printed copy taped inside my toolbox lid.

Troubleshooting: Using the Error Code Tables

Diagnosis / Troubleshooting is the longest section. It gives you the troubleshooting diagram, the layout of components and plug connections, and then the step-by-step for reading and deleting error codes. There is a full overview of error codes with remedies. For example, code 412 – supply air pressure too low. The manual tells you where to measure and what range is acceptable. The Table of Measurements on page [DATA NEEDED] (I will not invent a page number) lists expected voltages and resistances for every sensor and actuator. That is the kind of data that saves you from replacing parts that are not broken.

One thing I respect: the manual also covers operational control – how to test the retarder with the diagnostic tool while it is on the vehicle. No guesswork.

Who Needs This Manual

Owners of Actros trucks with the Retarder 115. Fleet mechanics who see these units in a mix of tractor-trailer work. Home garage enthusiasts who maintain their own heavy equipment. If you have ever been stuck with an intermittent electrical fault on a Voith retarder, you know that aftermarket manuals give you a generic wiring diagram that may or may not match. This manual matches. Also, if you need the Axor variant, check the Voith Retarder 115 H Axor Aftersales Service Manual. For lawn equipment, see White Outdoor LT-5 – 700 Series Rider Service Manual. For wiring diagrams of the Maruti, see Maruti MB308 Service Manual Procedures and Repair – Section: Section 8A Wiring D.

No shop should rely on a Chinese reprint when oil change intervals and error codes are at stake. This is the real thing.

Why This Isn’t a Third-Party Reprint

The file name alone tells you: VOITH_Retarder_115_Service_Manual_en-116309020162.pdf. That is an original OEM PDF from Voith’s aftersales division. Every page has the Voith logo and part number 53.2693.10. I have bought aftermarket “service manuals” that were just photocopies of the first 20 pages with the rest missing. Not this one. 146 complete pages, bookmarked, searchable. If you want to understand the function- and operation scheme, it is there. If you need the electrical connections for the R 115 H, page 4/8 has it.

The Retarder 115 works in conjunction with the drivetrain, including the Manual Transmission. For clutch and shift linkage, see the separate Manual Transmission manual – but for the retarder itself, this is the only factory documentation you need.

Does this manual include wiring diagrams?

Yes – the Electrical Connections Diagram on page 4/8 shows the full harness for the R 115 H.

What torque values are provided?

The Annex contains a complete tightening torques table listing Nm values for every fastener on the Retarder 115: heat exchanger bolts, oil tank cover screws, proportional valve mounting bolts, casing bolts, and more. You will need to convert to ft-lbs if your torque wrench reads imperial. Do not skip this table – overtightening the oil tank cover will crack the housing, and undertightening the heat exchanger bolts causes oil leaks. The data also includes thread sizes and tightening angles for critical joints. That level of detail is why OEM documentation beats any third-party summary.

When you are ready to start the job, get the exact data you need. Access the Factory Manual and keep it on your tablet next to the lift. No reprints, no approximations.