Bobcat 753 Hydrostatic Pump Removal Guide

[MikePhua]

Machine Overview
The Bobcat 753 is a compact skid-steer loader that was manufactured between roughly 1999 and 2003.  It is powered by a Kubota V2203-EB 4-cylinder diesel engine, producing around 43 hp.  The loader’s hydraulic system delivers about 15.9 gal/min (60.1 L/min) at a relief pressure of 2,750 psi, according to spec sheets.  This machine uses a hydrostatic drive, meaning the engine drives a pump that provides hydraulic power both to the drive motors and to the rest of the hydraulic system.

Why Remove the Hydrostatic Pump
There are several reasons to remove the hydrostatic pump on a 753:

• To repair or rebuild it due to wear (e.g., worn idler or drive gears, seals)
  
• To replace it if leaking or cracked (common failure point in older machines) as noted by long-time mechanics
  
• To inspect or clean internal components (bearings, O‑rings, couplers) for diagnosis or preventive maintenance
  

Step‑by‑Step Removal Procedure

1. Prepare the Machine
   • Raise the loader’s lift arms and install a certified lift-arm support to stabilize them.
     
   • Raise the cab so you can access the engine / pump assembly.
     
   • Drain the hydraulic reservoir to avoid fluid spillage during removal.
     
   • Disconnect the drive belt by loosening the belt‑tensioner, then remove the belt.
     
   • Remove the pulley from the hydrostatic pump shaft using a puller.
     
2. Remove the Pump
   • Once the belt is off, carefully unbolt the hydrostatic pump from its mounting. There are two main mounting bolts on the pump.
     
   • Ensure the engine/hydrostatic pump assembly is removed together because Bobcat’s service manual indicates they are designed to be lifted out as a single unit.
     
   • Use a lifting tool or hoist attached to the correct lift points on the engine‑pump assembly to lift it out cleanly.
     
3. Separate the Two Pump Halves
   • The 753 uses a split hydrostatic pump configuration. After removal, separate the two pump halves by removing the four mounting bolts.
     
   • Remove the coupler, then carefully take out the large O-ring and two smaller O-rings.
     
4. Inspect Internals
   • Once disassembled, inspect the idler gear, drive gear, wear plates, and various seals. Replace any parts showing excessive wear.
     
   • Check bushings and internal sections for scoring or damage; if wear is severe, replacing the pump may be more cost-effective.
     
5. Reinstallation
   • Clean all mating surfaces thoroughly before reassembly to prevent contamination.
     
   • Install new O-rings and seals.
     
   • Reassemble the two pump halves and torque the mounting bolts to the specified tightening value (65–70 ft-lbs / 88–95 Nm) for the pump mounting.
     
   • Reinstall the drive pulley onto the pump shaft, ensuring the key is properly seated before tightening the nut to about 175–200 ft-lbs (237–271 Nm).
     
   • Reinstall the drive belt and adjust tension according to Bobcat’s belt-tension procedure.
     

Common Challenges and Tips

• Several technicians note that it is possible to slide the hydrostatic pump out slightly for removal without fully removing the engine.  Yet, access is tight, and removing the pulley requires a proper puller on the keyed/tapered shaft.
  
• There is a small bolt at the bottom rear of the pump housing that is known to shear off in some machines, leaving too much load on the remaining mounting bolts.
  
• Keep everything clean during disassembly. Dirt inside a hydrostatic pump can cause serious internal damage.
  

Parts to Consider for Replacement
Here are some replacement or repair parts for the hydrostatic pump (or related assemblies):

• Bobcat OEM Hydrostatic Pump (7001896) – Genuine Bobcat part.
  
• Aftermarket Complete Tractor Hydrostatic Pump – More budget‑friendly, fits 753.
  
• Hydraulic Pump for Bobcat 6672513 – Common model used in 753/skid steer loaders.
  
• Hydrostatic Pump Rear Housing (replacement) – Useful if the housing is cracked or damaged.
  

Safety Precautions & Best Practices

• Use proper lifting equipment (chain hoist, engine removal tool) to avoid injury when handling the combined engine-pump assembly.
  
• Cap all hydraulic and motor ports when disconnected to prevent contamination.
  
• Wear gloves and eye protection: hydraulic fluid can be harmful and slippery.
  
• After reinstallation, bleed the hydrostatic system to remove trapped air, and carefully test the loader before resuming regular operation.
  

Conclusion
Removing the hydrostatic pump on a Bobcat 753 is a manageable but precise job. While the engine-pump assembly is ideally removed together, experienced mechanics have successfully pulled just the pump in place. Proper disassembly, inspection, and reassembly with new seals is essential for long-term reliability. With the right tools, replacement parts, and care for cleanliness, the job can restore lost hydraulic performance and extend the life of the loader.