Description

Hirschmann A2FM Technical Manual – What You Get on the Bench

If you’re digging into a Hirschmann A2FM fixed displacement motor, you want the real factory print — not a scanned copy that lost half the torque values. This 28-page technical manual is the same one the engineers at Brueninghaus Hydromatik used when they designed these axial piston units. I’ve torqued enough hydraulic motor flanges to know that aftermarket documentation will steer you wrong. This is the OEM source. It covers sizes 5 through 1000, open and closed circuits, up to 400 bar nominal and 450 bar peak. That’s serious pressure, and guessing gets expensive.

Need the flushing valve specs? Page 2 points you to the ordering code for size 5, and the actual valve data lives in the technical data section. The manual gives you the exact port plate configurations, drive shaft bearing options, and fluid recommendations. No generic tables that lump all motors together — this is specific to the A2FM bent-axis design. Whether you’re a shop owner tired of comebacks or a DIY guy who hates buying parts twice, this is the doc that keeps the job straight.

Flushing Valve Data – Why It’s in the Manual

The table of contents lists a dedicated section on the flushing valve. That valve controls cooling flow in the closed loop, and if you get the wrong spec, the motor cooks itself. The manual breaks out the flushing valve flow rates and pressure settings per size. Page 8 has the ordering code for size 5, so you can match the exact valve to your motor. I’ve seen guys slap a generic valve on an A2FM and wonder why the case drain runs hot. Don’t be that guy.

Ordering Code Decoding – Size 5 Through 1000

Flip to page 2 and you’ll see the ordering code matrix. It’s not a simple part number — it encodes the shaft end, mounting flange, seals, bearings, and port configuration. The manual explains each digit. For example, a splined shaft is code A; a parallel shaft with key is B. The preferred program lists specific combinations that are stocked. If you’re ordering a replacement motor, you need this code to make sure the new unit matches your existing plumbing and mount. Aftermarket catalogs guess; this manual doesn’t.

Technical Data – Fluid, Table of Values, Output Drive

This manual doesn’t just throw numbers at you. The fluid section tells you acceptable viscosities and contamination limits for mineral oil and HF-fluids. The table of values gives you displacement, nominal torque, and pressure ratings per size. Output drive data covers the spline and keyway dimensions. For a 28-page doc, it packs the critical measurements you need to machine adapter plates or choose a coupling. I keep a copy at each bay in my shop — saves a call to the parts guy every time.

Unit Dimensions – Getting the Mount Right

From size 5 to size 1000, every motor gets its own dimension sheet. Port plates are drawn for sizes 28 through 1000, including the port plate 19 pattern for sizes 28…180. You get SAE and metric port options, flange bolt patterns, and shaft extension lengths. Measure twice, order once. If you’re retrofitting a motor in a skid loader or a hydraulic fan drive, these dimensions are your blueprint. The manual also covers port plate options like pressure relief valves at side or rear — stuff that matters when clearances are tight.

Who Needs This Manual?

Mobile equipment mechanics, industrial hydraulic techs, and serious home-shop guys who rebuild hydrostatic drives. If you’re working on a crane, a concrete pump, or any machine with an A2FM motor, this is your spec book. Beginners will appreciate that the ordering code logic keeps them from ordering the wrong part. Pros will use the torque specs and port dimensions to avoid leaks on startup. And shop owners — having a fleet of these manuals cuts down the time a tech spends digging through online forums for a number that’s probably wrong.

Source Authenticity – OEM Factory Documentation

This is not a third-party rewrite. It’s the original Mannesmann Rexroth technical manual (RE 91001/01.97), reproduced in full. The Hirschmann branding on the cover matches the official distribution channel. I’ve seen aftermarket versions that combine multiple motor families into one PDF — that’s how you get a torque value for a size 10 that was actually meant for a size 100. This manual is size-specific, with separate dimension sheets for each displacement. Trust the factory print, not a compilation.

For related OEM manuals, check out Hirschmann HC4900 2014 User Manual – Load Moment Indicator OEM Specs or Hirschmann QUY260 2009 User Manual – Factory Load Moment Indicator Guide. Also see Hirschmann HC4900 2014 User Manual – OEM LMI Guide for crane electronics. And if you need a refresher on how a Manual Transmission works, that’s a different skill set — this manual stays on the A2FM.

Does this manual cover all A2FM sizes including the flushing valve?

Yes. It covers sizes 5 through 1000, with separate dimension sheets and a dedicated flushing valve section in the technical data.

Can I use this manual to rebuild an A2FM motor that was originally sold by a different brand?

If the motor is an original Brueninghaus Hydromatik/Rexroth A2FM, yes — the design is identical regardless of the distributor label on the data plate. This manual is the factory doc for that motor family. However, if the motor has been modified or is a clone, the torque specs and port dimensions may not match. Always verify the model code against the ordering code table on page 2 before ordering seals or bearings. I’ve seen DIYers mix up a size 28 with a size 32 because the housing looked similar — that mistake costs a week of downtime when the shaft seal leaks at 400 bar.

Access the Factory Manual now and put the right numbers in your torque wrench. No more searching through mismatched PDFs or calling tech support. This is the document that keeps your hydraulic motor running at peak efficiency.