March 01, 2013

How to replace a log splitter flexible pump coupler

How to replace a log splitter flexible pump coupler

This DIY repair guide explains how to replace the flexible log splitter pump coupler. The hydraulic pump coupling connects the engine drive shaft to the hydraulic pump. The coupler is designed to break if the hydraulic pump seizes up, protecting the engine from damage. The log splitter pump coupler deteriorates over time, causing vibration and noise when the hydraulic pump is running. If the log splitter hydraulic pump coupling breaks or the coupler is worn, use the manufacturer-approved replacement part to install a new one.

Use these steps to replace the flexible pump coupler on Craftsman, MTD and Troybilt log splitters.

Quick links
Tools required
Wrench set
Thin 1/2-inch wrench
Work gloves
Repair difficulty
Time required
15 minutes or less
Repair difficulty
Time required
15 minutes or less

Instructions

  1. 01.

    Disconnect the spark plug wire

    Disconnect the spark wire so there's no chance that the log splitter engine could accidentally start.

    PHOTO: Disconnect the spark plug wire.

    PHOTO: Disconnect the spark plug wire.

  2. 02.

    Remove the hydraulic pump

    Using the thin 1/2-inch wrench to keep the hex-head bolts from moving, remove the 3 flange lock nuts from the hex-head bolts that secure the pump to the flexible pump coupler shield.

    Pull the pump off of the engine.

    Tip: The thin 1/2-inch wrench fits in the small space between the heads of the hex-head bolts and the side of the engine.
    PHOTO: Remove the flange lock nuts.

    PHOTO: Remove the flange lock nuts.

    PHOTO: Remove the pump from the engine.

    PHOTO: Remove the pump from the engine.

  3. 03.

    Remove the flexible pump coupler

    Slide the coupling shield off of the hex-head bolts on the side of the engine.

    Pull the flexible pump coupler out of the coupler halves.

    Clean any residue from the broken flexible pump coupler out of the coupler halves.

    PHOTO: Remove the coupling shield.

    PHOTO: Remove the coupling shield.

    PHOTO: Remove the flexible coupler.

    PHOTO: Remove the flexible coupler.

  4. 04.

    Install the new flexible pump coupler

    Reinstall the coupling shield.

    Position the new flexible pump coupler on the pump-side coupler half.

    Slide yourself under the coupling shield so you can guide the coupler halves together.

    Push the pump onto the hex-head bolts and guide the pump-side coupler half into the engine-side coupler half, rotating the pump-side coupler half to line up the coupler halves.

    Reinstall the 3 flange lock nuts on the hex-head bolts to secure the pump on the engine. Tighten the 3 flange lock nuts securely.

    Tip: Use the thin 1/2-inch wrench to hold the hex-head bolts stationary as you reinstall and tighten the 3 flange lock nuts on the base of the hydraulic pump.
    PHOTO: Reinstall the coupling shield.

    PHOTO: Reinstall the coupling shield.

    PHOTO: Reinstall the flexible coupler.

    PHOTO: Reinstall the flexible coupler.

    PHOTO: Reinstall the hydraulic pump.

    PHOTO: Reinstall the hydraulic pump.

    PHOTO: Reinstall the flange lock nuts.

    PHOTO: Reinstall the flange lock nuts.

  5. 05.

    Reconnect the spark plug wire

    Attach the spark plug wire and make sure the log splitter engine works properly.

    PHOTO: Reconnect the spark plug.

    PHOTO: Reconnect the spark plug.

  6. 06.

    Test the hydraulic pump operation

    Start the log splitter and test the operation of the hydraulic pump and the flexible coupler.

Warning: Undertaking repairs to appliances can be hazardous. Use the proper tools and safety equipment noted in the guide and follow all instructions. Do not proceed until you are confident that you understand all of the steps and are capable of completing the repair. Some repairs should only be performed by a qualified technician.

Most common symptoms to help you fix your log splitters

Choose a symptom to see related log splitter repairs.

Main cause: worn hydraulic cylinder seals…

Main cause: worn hydraulic valve seals around the actuator rod…

Main causes: broken pump coupler, clogged hydraulic fluid filter, bad hydraulic control valve, broken hydraulic pump, ba…

Main causes: leaky head gasket, damaged sump gasket, leaky oil drain plug, damaged fuel line, bad carburetor seals…

Main cause: worn hydraulic pump seals…

Main causes: dirty carburetor, bad spark plug, clogged air filter, stale fuel…

Main causes: dirty carburetor, stale fuel, bad spark plug, broken recoil starter…

Most common repair guides to help fix your log splitters

These step-by-step repair guides will help you safely fix what’s broken on your log splitter.

How to replace a log splitter flexible pump coupler

How to replace a log splitter flexible pump coupler

The flexible nylon log splitter pump coupler deteriorates over time. Replace the flexible pump coupler if it begins to v…

Repair difficulty
Time required
 15 minutes or less
How to replace a log splitter recoil starter

How to replace a log splitter recoil starter

The recoil starter spins the engine on the log splitter when you pull the starter rope, and the rope retracts when relea…

Repair difficulty
Time required
 15 minutes or less
How to replace a log splitter carburetor

How to replace a log splitter carburetor

The carburetor mixes air and gas before the fuel mix goes to the engine. If the engine won't start and the spark plug is…

Repair difficulty
Time required
 30 minutes or less

Effective articles & videos to help repair your log splitters

Use the advice and tips in these articles to get the most out of your log splitter.

Find the right carburetor assembly for a Craftsman snowblower, tiller or log splitter

Find the right carburetor assembly for a Craftsman snowblower, tiller or log splitter

This chart will help you find the right carburetor for your Craftsman snowblower, tiller or log splitter.…

How to maintain the hydraulic system in a log splitter

How to maintain the hydraulic system in a log splitter

See how to properly maintain the hydraulic system in your log splitter.…

How to change the hydraulic fluid in a log splitter

How to change the hydraulic fluid in a log splitter

Learn how to change the hydraulic fluid in your log splitter.…