Support

Everything you need to set up, run and maintain your Rockcub 7-ton electric log splitter, models RCV8 and RCV8+. If you cannot find an answer here, call or email us and a person in Whittier, California will pick it up.

Rockcub support. support@rockcuboutdoors.com · +1 (562) 203-3004
Monday to Friday, 9:00–5:00 Pacific. Have your order number, model (RCV8 or RCV8+) and serial number ready. Model and serial are on the main identification label.

Manuals and videos

Set up in 5 minutes

The splitter arrives with the hydraulic oil already in it. The frame, support legs, wedge and log retaining plates are fitted at the factory. You fit the wheels and the hydraulic control lever with the wrench and hex key in the box, then swap the shipping plug for the bleed screw. Keep the machine unplugged until the last step.

  1. Unbox. Lift the splitter out by the handles at both ends and place it on a stable, flat, level work surface 24 to 30 inches high. Press the four rubber feet onto the support legs.
  2. Remove the four nuts from the studs on the valve block (the aluminum block beside the motor). Keep them.
  3. Fit the control lever guard onto the two upper studs and tighten it with two of the nuts.
  4. Fit the axle bracket, then the lever, on the lower studs. Slide the axle bracket (with the wheels) onto the studs and add a washer. Slide the eye of the control lever onto the same stud, then the bushing, the second washer and the nut. Tighten both nuts with the wrench. Pull the lever once to check it moves freely.
  5. Swap the shipping plug for the bleed screw. Remove the solid plug on top of the tank with the hex key and fit the air bleed screw from the bag. Loosen it 3 to 4 turns. You should feel air moving at the hole while the machine runs.
  6. Bolt the splitter to the work surface, plug in (see power requirements below) and cycle the ram twice with no log to confirm it extends fully and returns when you release the controls.
Removing the four nuts from the valve block
Step 2. Four nuts off the valve block.
Fitting the control lever guard
Step 3. Guard on the upper studs.
Fitting the axle bracket and lever
Step 4. Axle bracket, then lever: washer, lever, bushing, washer, nut.
Swapping the shipping plug for the bleed screw
Step 5. Plug out, bleed screw in, 3 to 4 turns loose.

The bleed screw is the one step people skip. Running with it closed traps air in the hydraulic system and blows out the seals. That damage is not covered by the warranty. Open it 3 to 4 turns before every session, and tighten it again before you move or store the splitter.

Something wrong? Start here

Find what you see in the left column, try the fix, and follow the link for the full steps. Most first-day problems are the stuck pump, the bleed screw or the circuit, and all three take a minute to put right.

What you see Most likely cause What to do
Motor hums but does not turn, on the first start or after storage Gear pump stuck: fresh oil holds the gears together and the motor cannot break them loose Unplug. Push a pencil or a small screwdriver through a vent slot on the end of the motor and turn the fan 5 to 10 turns, then try again. Watch the fix. If it still only hums, contact us.
Motor will not start, no hum Overload protection has tripped Unplug and let the motor cool. The overload device is inside the pushbutton box, which only an electrician should open. Contact us before anything else.
Breaker trips at start or at the end of the stroke Shared or undersized circuit, long thin cord, or holding pressure at the end of the stroke Dedicated circuit, 15 A minimum, 20 A recommended, nothing else on it. 12 AWG cord under 33 ft, or plug straight into the wall. Release the controls as soon as the log splits. Power requirements.
Log pusher (ram) creeps a few inches, stalls, or does not retract Bleed screw closed, low oil, or the control valve not returning to neutral Open the bleed screw 3 to 4 turns. Check the oil. If it still does not retract, reset the control valve with screw 15. Steps and video.
Pusher moves jerkily, vibrates or makes an unusual noise Bleed screw not open, low oil, or air in the system Open the bleed screw 3 to 4 turns. Check the oil and top up with ISO VG 46. If it persists, contact us.
Log will not split Oversized, knotty or crooked log, or positioned wrong Square-cut end against the pusher. Reposition or reduce the log. Never hold pressure more than 2 seconds. Operating.
Fails to split, and the wedge looks dull Blunt cutting edge Sharpen with a fine-toothed file, smoothing away burrs and crushed areas.
Log is stuck on the wedge Normal with twisted grain Scrap wedge under the log and let the pusher lift it off. Never knock it off. How to free a jam.
Weak splitting after someone adjusted the machine Maximum pressure limiting screw tampered with Stop using the machine and contact us. Do not attempt to reset it.
Oil leaking around the cylinder ram Bleed screw closed while running, so air is trapped in the system Loosen the bleed screw 3 to 4 turns before operating.
Oil leaking after moving the machine Bleed screw left open during transport Always tighten the bleed screw before moving the splitter.
Oil leaking at the drain bolt Drain bolt loose Tighten it securely.
Leaks anywhere else, or a worn control valve Seal or valve wear Locate the leak, then contact us. Do not keep running the machine.

Motor hums but does not turn? This video shows the fix, start to finish.

Log pusher (ram) won't retract, or retracts slowly? Reset the control valve with screw 15, the maximum pressure limiting screw on the valve block beside the control lever guard. Draw a pen line across the screw head first so you can count turns. Keep the splitter empty and unplug it every time you turn the screw.

  1. Loosen screw 15 by 4 full turns.
  2. Press the control lever down and release it, 2 or 3 times. The log pusher should retract. If it is still stuck or slow, loosen 2 more turns and repeat.
  3. Tighten screw 15 by 2 turns.
  4. Plug in. Press the lever together with the foot pedal (RCV8+) or green button (RCV8), run the log pusher to the end, then release both. It should retract on its own.
  5. Unplug, tighten 2 more turns and repeat step 4, until you have tightened exactly as many turns as you loosened.

Always return screw 15 to its original position. It sets the maximum splitting pressure. This reset does not affect your warranty. If the log pusher still does not retract afterwards, stop using the splitter and contact us.

Power requirements

A standard grounded 120 V, 60 Hz outlet on a dedicated circuit with nothing else running on it. The splitter is rated at 15 A: a 15 A circuit is the minimum, a 20 A circuit is recommended. A circuit shared with other appliances will trip the breaker. A GFCI outlet is strongly recommended. If you need an extension cord, keep it under 33 ft, rated for 20 A, and 12 AWG or heavier; a long thin cord starves the motor and overheats it. A generator running the house after an outage can trip the splitter too.

Operating

  • Set the log firmly against the wedge with both ends cut square and branches cut flush. Check for nails and foreign objects first.
  • RCV8: press and hold the green motor button with your right hand and pull the black control lever with your left. The pusher advances. Release both and it returns.
  • RCV8+: hold the control lever with one hand and press the foot pedal. Release both and the pusher returns.
  • If a log will not split, do not hold pressure for more than two seconds. Release the controls at once. Holding pressure on a stubborn log damages the motor.
  • The motor is rated for intermittent duty (S6 40%). In any 10 minutes, run it no more than 4 minutes in total. Splitting, loading the next log, splitting again stays inside that rhythm; do not run the ram back and forth continuously.
  • Never turn the machine on its side or upside down while in use.
  • Do not change the maximum pressure setting. The limiting screw on the valve block is set and sealed at the factory so the machine cannot exceed 7.5 tons. The only time to turn it is the control valve reset, which ends with the screw back where it started. Any other change can cause serious injury, will damage the machine and voids the warranty.

Fitting the 4-way cross wedge

Both models ship with a 4-way cross wedge. It fits over the standard wedge and is held by one bolt through the side. Use it for straight-grained rounds, where one stroke makes four pieces. Use the standard 2-way wedge for knotty, twisted or oversized rounds.

Fitting the 4-way cross wedge: slide it down over the standard wedge, then fit the side bolt
Left. Unplug, then slide the cross wedge straight down over the standard wedge. Right. Fitted, bolt through the hole in the side and tightened.
  1. Release both controls so the pusher returns fully, and unplug the machine.
  2. Slide the cross wedge down over the standard wedge until it seats fully.
  3. Fit the bolt through the hole in the side and tighten it with the wrench.
  4. Check that the wedge is square and does not move. To go back, reverse the steps.

Checking and topping up the hydraulic oil

The tank is filled at the factory. There is nothing to add before the first use. Check the level at the start of each season, and whenever the pusher moves jerkily or vibrates.

  1. Release both controls so the pusher returns fully, and unplug the machine.
  2. Stand the splitter upright with the oil port and dipstick at the top.
  3. Unscrew the oil drain bolt, wipe the dipstick, rest it back in the port without screwing it in, and read the level.
  4. The level should sit between the two marks. If it is at or below the lower mark, pour ISO VG 46 (AW-46) hydraulic oil through a funnel until it reaches the upper mark. Do not overfill.
  5. Refit the drain bolt and tighten it, return the machine to horizontal, and check the bleed screw is still 3 to 4 turns loose before use.
Dipstick with the two level marks magnified
Upper mark: full. Lower mark: add oil.
Splitter standing upright with the oil port at the top
Top up with the splitter upright, oil port at the top.

Change the oil every 150 hours of use. Any major brand's ISO VG 46 anti-wear hydraulic oil works, for example Shell Tellus S2 M 46 or Mobil DTE 25. Do not substitute a lighter or heavier grade. Tank capacity is 0.8 gal (3 L).

Freeing a jammed log

  1. Release both controls and wait until the pusher has returned fully and stopped.
  2. Place a wedge-shaped piece of scrap wood under the jammed log, thin end first.
  3. Run the pusher so it drives the scrap under the log and lifts it off the wedge. Repeat with a steeper piece if needed.
Scrap wedge placed under the jammed log
Right. Scrap wedge under the log.
Crossed out: striking the jammed log with a hammer
Wrong. Never knock the log or the wedge.

Never strike the log or the wedge with a hammer, mallet or bar, never pull the log by hand, and never have a second person help.

Maintenance

  • Every session: open the bleed screw before you start, tighten it before storage, and wipe the ram and wedge clean.
  • Keep the machine clean and dry. Never expose it to rain or operate it in wet or damp conditions.
  • Sharpen the wedge with a fine-toothed file when it dulls.
  • Change the hydraulic oil every 150 hours with ISO VG 46 (AW-46). Dispose of used oil at an authorized collection point.
  • Operating range is 41–104°F. Store and transport between −13 and 131°F, upright.

Safety

  • One operator, always. Keep everyone else well clear while the machine runs.
  • Safety goggles and hearing protection. Everyday eyeglasses are not a substitute.
  • No loose clothing, neckties or jewelry. Non-conductive protective gloves and non-slip footwear are recommended. Tie back long hair.
  • Keep hands clear of splits and cracks that open in the log. They can close suddenly and crush or amputate.
  • Never free a jammed log by hand, and never load a log until the pusher has come to a complete stop.
  • Unplug the machine when it is not in use, and before any adjustment, parts change, cleaning or service.
  • Never operate on the ground. Bolt the splitter to a work surface 24 to 30 inches high.
  • Never stand on the splitter, and do not operate under the influence of drugs, alcohol or medication, or near paint, solvent or flammable-liquid fumes.

Warranty

Every Rockcub log splitter is covered by a 1-year limited warranty from the date of purchase against defects in materials and workmanship. We handle warranty claims ourselves from California, not through a marketplace.

The warranty does not cover normal wear on the wedge and ram surfaces, damage from running with the bleed screw closed or with low oil, damage from changing the pressure limiting screw from its factory position (the control valve reset on this page does not affect your warranty), or damage from commercial or rental use. Arrived damaged or dead on arrival? Tell us within 7 days of delivery with photos or a short video and we will replace it or refund you, shipping on us.

Before you contact us

Three things get a problem solved in one email instead of four:

  • Your order number and where you bought it (rockcuboutdoors.com or Amazon).
  • Your model and serial number, from the identification label on the machine.
  • A short video of what happens when you press both controls, or photos of the problem. Tell us what outlet and cord it is plugged into.

Email support@rockcuboutdoors.com or call +1 (562) 203-3004, Monday to Friday, 9:00–5:00 Pacific.

Replacement parts

Wedges, the 4-way cross wedge, bleed screws, marked dipsticks and other wear items are stocked in the U.S. Email us with your model and serial number and we will tell you whether we can supply the part you need.

Disposal

Waste electrical products must not go in household waste. Recycle at a designated facility. Take used hydraulic oil to an authorized collection point.