Service Manual For Bomag Bmp851 <LATEST – 2026>

The Ultimate Guide to the Service Manual for Bomag BMP851: Why You Need It and How to Use It

In the world of heavy compaction equipment, the Bomag BMP851 stands out as a legendary "Rammax" series reversible vibratory plate. Known for its brutal efficiency in compacting granular soils, gravel, and asphalt in trenches and confined areas, this machine is a workhorse on construction sites from Berlin to Brisbane.

However, even the most robust German-engineered equipment requires meticulous maintenance. If you own, operate, or repair this machine, you have likely typed the phrase "service manual for Bomag BMP851" into a search engine. You are not alone.

A genuine service manual is not just a booklet; it is the single most critical tool for preventing downtime. This article dives deep into what the BMP851 service manual contains, why a generic PDF won’t cut it, and how to perform the most critical procedures using official guidance.

6. Hydraulic System

The BMP 851 uses a closed-loop hydrostatic circuit for drum drive and an open-loop circuit for vibration and steering. service manual for bomag bmp851

Key components:

  • Variable displacement pump (Linde HPV-02 or similar) – drives front and rear drum motors in series.
  • Charge pump (integral) – supplies 25 bar to closed loop.
  • Vibration pump – gear pump, 15 cc/rev.

Pressure checks:

  • System relief pressure: 320 bar ±10 bar.
  • Charge pressure: 15–25 bar at idle, 20–30 bar at full throttle.
  • Vibration circuit: 180 bar (low freq) / 220 bar (high freq).

Troubleshooting – low drive power:

  1. Check charge pressure – if low, inspect charge filter (bypass valve may be stuck).
  2. Measure case drain flow from drum motors – >5 L/min indicates motor wear.
  3. Test pump stroke via solenoid (forward/reverse) – if no movement, solenoid coil resistance should be 12–15 Ω.

Hydraulic oil change procedure:

  1. Warm oil to 40°C.
  2. Remove drain plug under tank (catch 28 L).
  3. Replace return filter (10 μm absolute).
  4. Refill with ISO VG 46 (anti-wear).
  5. Bleed: Loosen highest hose fitting (vibration motor case) and run engine at idle for 10 sec.

Fluids, Lubricants & Consumables (Examples — confirm with manual)

  • Engine oil: SAE grade and capacity per engine spec (check engine plate).
  • Hydraulic oil: ISO VG grade (manufacturer-recommended), change interval per PM chart.
  • Grease: NLGI grade and type for pivot points (commonly lithium-complex).
  • Coolant: Ethylene or propylene glycol mix per engine spec.
  • Filters: Engine oil filter, fuel filter(s), hydraulic filter — use OEM part numbers.

3. Engine Service Appendix

Most BMP851 units use either a Honda GX390 (petrol) or a Lombardini LDW series (diesel). The manual includes a dedicated sub-section for valve clearance adjustments, carburetor tuning, and decompression valve checks specific to the mounting configuration.

3. General Specifications

| Parameter | Value | |-----------|-------| | Operating weight | 1,500 kg (approx.) | | Drum width | 850 mm | | Drum diameter | 560 mm | | Vibration frequency | 55 Hz (3,300 vpm) / 48 Hz optional | | Centrifugal force | 18 kN (low) / 28 kN (high) | | Engine power | 10.4 kW @ 3,000 rpm | | Hydraulic oil capacity | 28 L | | Fuel tank | 22 L | The Ultimate Guide to the Service Manual for

Problem 2: Plate shakes violently at the handle.

  • Manual reference: Section 7 – Vibration Isolators.
  • Diagnosis: Worn rubber isolator mounts. The manual provides a torque sequence for replacing all four mounts simultaneously. Replacing only two will cause asymmetric vibration.

3. Torque and Tightening Specs

Have you ever wondered exactly how tight the drum bolts should be? Over-tightening can strip threads; under-tightening leads to dangerous loosening during operation. The manual lists every bolt class and its corresponding torque value.

Where to Download or Buy the Official Manual

As of 2025, the best sources for the service manual for Bomag BMP851 include:

  1. Bomag Digital Library (bomag.com): Enter your model and serial number. You can view individual pages for free, but downloading the full PDF requires a subscription or one-time fee.
  2. Wirtgen Group Shop: Bomag is owned by Wirtgen. Their parts catalog often includes free downloads of the operator's manual, but the service manual is a paid item.
  3. eBay / Amazon: Use with caution. Look for sellers offering a high-resolution scan. Ask for a preview of a torque table before buying. Counterfeit manuals with missing pages are rampant.
  4. Local Bomag Dealer: If you have a physical dealership nearby (e.g., LeeBoy in the US, LBS in the UK), they will print and bind a manual for you for roughly $200.