Cat Excavator Hydraulic Pumps and Pump Couplers

Main hydraulic pump and couplers for Caterpillar excavators, covering a wide range of compact and full-size machines from the 311C through the 336D. Main hydraulic pump and couplers are critical to maintaining proper hydraulic system function — worn or failed couplers lead to pump slippage, vibration, and loss of hydraulic pressure.

Fits Models At A Glance

• 300C Series: 311C, 312C, 313B, 314C
• 300D Series: 311D, 312D, 314D, 314DLCR, 320D, 330D, 336D

Key Notes

• Application: Connects engine flywheel to hydraulic pump drive; critical for pump engagement and pressure output
• Fitment Range: Spans compact excavators through large production excavators
• Condition: New replacement couplers available for all listed models

Why Choose Broken Tractor

• ✅ Accurate fitment data matched to Cat model and serial range
• ✅ Fast shipping from Baton Rouge, LA and Kimbolton, OH
• ✅ Dedicated Cat excavator parts specialists ready to assist

Frequently Asked Questions

What does the hydraulic pump coupler do on a Cat excavator?

The pump coupler connects the engine flywheel to the hydraulic pump drive, so it transfers engine power to the main hydraulic pump. It is critical for proper pump engagement and pressure output. If the coupler wears out, the pump cannot be driven reliably and the whole hydraulic system suffers.

What are the symptoms of a bad hydraulic pump coupler on a Cat 320D excavator?

A worn or failed pump coupler on a Cat 320D typically causes pump slippage, vibration, and loss of hydraulic pressure. These symptoms happen because the coupler can no longer transfer engine power to the pump drive cleanly. Replacing a worn coupler early helps keep proper hydraulic system function.

Which Cat excavator models do you carry hydraulic pump couplers for?

Broken Tractor carries main hydraulic pump and coupler parts for Cat 300C series excavators, including the 311C, 312C, 313B and 314C. We also cover 300D series machines, including the 311D, 312D, 314D, 314DLCR, 320D, 330D and 336D. That range spans compact excavators through large production excavators.

How do I find the right pump coupler for my Cat 312C excavator?

Fitment for Cat excavator pump couplers is matched to both the model and the serial number range, so check your machine's serial number before ordering. Matching the part number from your old coupler is the most reliable way to confirm the correct part. If you are unsure, call (800) 909-7060 and our Cat excavator parts specialists can help confirm fitment.

Are the Cat excavator pump couplers new or used?

Broken Tractor offers new replacement pump couplers for all of the listed Cat excavator models, from the 311C through the 336D. Each coupler is matched to Cat model and serial range fitment data. Orders get fast shipping from Baton Rouge, LA and Kimbolton, OH.