RV leveling jacks or stabilizers not working: what to check

Types of RV leveling and stabilizing systems

• Stabilizer jacks (scissor or drop-down): These steady the RV, but most are not designed to lift it. Using them to level can bend them.
• Electric leveling jacks: Motorized jacks that can lift the RV to level, often with an auto-level controller.
• Hydraulic leveling systems: A pump, reservoir and hydraulic cylinders. Common on motorhomes and fifth wheels.
• Tongue jacks and fifth-wheel landing gear: These front jacks also fail in similar ways.

Safety: Never crawl under an RV supported only by leveling jacks, stabilizers or a tongue jack. Use proper jack stands rated for the load and chock the wheels with wheel chocks. Keep hands and feet away from jack feet. Hydraulic systems run at high pressure. Never loosen fittings under pressure, and keep skin away from leaks.

Step 1: Check the obvious

• Is the engine running or the parking brake set, if your system requires it?
• Is the RV in Park with the ignition in the correct position (for motorhomes)?
• Is the control panel on and showing an error code? Look up the code in the manual. Many explain exactly what's wrong (low voltage, excess slope, sensor fault).
• Is anything blocking the jacks, such as a rock, curb, snow or ice?

Step 2: Voltage and power

Like slides, leveling systems draw big current. Low battery voltage causes slow movement, error codes or a system that won't start.

1. Measure battery voltage with a Digital multimeter (auto-ranging, with DC amps) while operating.
2. Charge the battery, run the engine (motorhomes) or connect the tow vehicle.
3. Check fuses and breakers for the leveling system, often a large inline fuse or breaker near the battery or pump.
4. Check ground connections. Corroded grounds near the pump are common on rigs exposed to winter road salt.

Step 3: Hydraulic systems

• Fluid level: Check the reservoir with jacks fully retracted (unless the manual says otherwise). Use only the fluid type the manufacturer specifies. Mixing types can damage seals.
• Leaks: Look for wet fittings, hoses and cylinder rods. A slow leak can drop a jack over hours.
• Pump runs but jacks don't move: Low fluid, a stuck valve or an air lock. Follow the manufacturer's bleeding procedure.
• Jack won't retract: May be a sticking solenoid valve or a weak retraction spring. Most systems have a manual release valve.

Step 4: Electric jacks

• Listen at the jack motor while operating. Silence with voltage present at the connector suggests a failed motor.
• Check for a stripped gear or worn screw if the motor runs but the jack doesn't move.
• Look for frayed wiring where it passes near the jack. Jack movement and road debris can chafe wires.

Step 5: Auto-level errors

Auto-level controllers use a tilt sensor. Common issues:

• Too much slope: The system can't level beyond its range. Move to flatter ground or use leveling blocks under the tires first.
• Sensor needs calibration: If it reports level when the RV obviously isn't, recalibrate the "zero point" per the manual. You'll usually need a bubble level on the floor.
• Soft ground: Jacks sinking into soft ground or gravel keep the system hunting. Use jack pads under each foot.

Manual retraction

Know how to retract your system manually before it fails:

• Hydraulic: Usually a release valve on each cylinder or the manifold, and sometimes a manual pump handle.
• Electric: Often a hex or square drive on the motor end so you can wind the jack up with a ratchet or drill adapter.
• Stabilizers: Hand crank or drill.

Store the manual crank and instructions in a known spot in the RV.

Leveling tips that prevent failures

• Lower the tongue or landing gear onto a pad, not straight onto soft ground.
• Level side-to-side with blocks under the tires first, then front-to-back with the jacks.
• Don't lift the wheels off the ground unless the manufacturer allows it. It can stress the frame and may make the RV less stable.
• Retract and inspect jacks before travelling, and add a walk-around to your pre-trip routine. See the pre-trip checklist.
• In winter, ice can freeze jack pads to the ground. Free them before retracting.

When to call a pro

Bent jacks, damaged mounting brackets or frame welds, hydraulic pump or cylinder replacement, or any jack that drops unexpectedly.