This document is a service manual for BAHCO BH6 series cranes, specifically addressing a common issue of pump oil leaks. The manual provides detailed instructions for diagnosing and repairing these leaks, catering to both in-warranty and out-of-warranty units.

Function Description:

The BAHCO BH6 series cranes (models BH6PC600, BH6FC1000, BH6FC2000) are hydraulic lifting devices. The pump assembly is a critical component responsible for generating the hydraulic pressure required to operate the crane's lifting mechanism. The manual focuses on the valve locking knob within the pump assembly, which, when not properly tightened or sealed, can lead to oil leaks. The primary function of the repair procedure outlined is to restore the integrity of this valve, preventing oil leakage and ensuring the pump's efficient operation.

Important Technical Specifications:

The manual references specific pump assembly codes for different crane models:

BH6PC600: Uses pump assembly code BH6FC1000-10
BH6FC1000: Uses pump assembly code BH6FC1000-10
BH6FC2000: Uses pump assembly code BH6FC2000-10

While detailed technical specifications of the pump itself (e.g., flow rate, pressure rating) are not provided, the manual emphasizes the use of Loctite 270 for sealing the threads of the valve locking knob and the valve screw. Loctite 270 is a high-strength threadlocker designed for permanent locking and sealing of threaded fasteners, preventing loosening from vibration and shock. Its application is crucial for ensuring a durable, leak-free seal. The manual also specifies the use of Hydraulic Oil ISO VG 15 for refilling the pump, indicating the type of hydraulic fluid compatible with these cranes.

Usage Features:

The manual primarily focuses on maintenance rather than general usage. However, it implicitly highlights the importance of a properly functioning pump for the crane's operation. A leaking pump indicates a malfunction that would impair the crane's ability to lift and hold loads effectively. The repair process ensures that the crane can be used safely and efficiently without loss of hydraulic fluid.

Maintenance Features:

The core of this document is a step-by-step guide for maintenance and repair.

Diagnosis: The manual identifies the primary cause of oil leaks as an incorrectly tightened or unsealed valve locking knob. Visual inspection for small amounts of oil leakage around the pump is the initial diagnostic step.
Warranty Policy: For units under warranty, the official action is a complete pump assembly replacement. This indicates that for new units, a leak is considered a significant defect warranting a full component swap.
Out-of-Warranty Repair (DIY): For units out of warranty, or for end-users willing to perform the repair, a detailed procedure is provided. This empowers users to extend the lifespan of their equipment without needing a full replacement.
Disassembly: The process begins with disassembling the pump assembly and placing it on a workbench. A video guide is provided for assistance with pump disassembly if needed.
Valve Knob Removal: Instructions are given to remove the valve screw (counterclockwise) and then the valve knob itself (strongly counterclockwise). The manual advises using tools if the knob is too tight to unscrew by hand.
Cleaning and Sealing: Both male and female threads of the valve assembly must be thoroughly cleaned and dried. Loctite 270 is then applied around the entire male thread surface. A crucial instruction is to wait approximately one minute after applying Loctite to ensure it penetrates the threads and to avoid excess, which could block the valve relief system.
Reassembly: The valve knob is reassembled and screwed clockwise until fully tightened by hand.
Valve Screw Sealing and Tightening: Any excess Loctite is cleaned from the area. Loctite 270 is then applied around the valve screw. After waiting for about a minute, the screw valve is assembled and tightened clockwise using a wrench.
Drying and Testing: The Loctite needs a couple of hours to dry. During this period, the user is instructed to periodically check the valve knob by opening and closing it to ensure it does not become blocked.
Pump Reassembly: After the Loctite has dried and the valve is confirmed to be functional, the pump is reassembled. Another video guide is provided for assistance with pump reassembly.
Purging and Refilling: The final step involves purging air from the pump and refilling it with Hydraulic Oil ISO VG 15. A video guide is also available for this process, ensuring proper hydraulic system function after the repair.

This comprehensive maintenance guide ensures that users can effectively address pump oil leaks, prolonging the operational life of their BAHCO BH6 series cranes and maintaining their performance. The inclusion of video guides for complex steps significantly enhances the usability and accessibility of the repair instructions.

Bahco BH6 - Page 9