RV levelling jacks will not extend
What this usually means
This is the benign direction of the same fault. Jacks that will not come down leave the coach fully drivable, so you have time to deal with it properly rather than urgently. The usual causes are inadequate voltage, low hydraulic fluid, or a safety interlock refusing because it thinks the coach is not ready.
Check this first
Check whether an interlock is refusing. Many systems will not deploy with the ignition on, the parking brake off, or a door open, and a system that seems dead is often a system doing what it was told.
Stop-work system
Leveling jacks hold the coach’s weight. Never go under an RV supported only by its jacks, and never troubleshoot a jack under load.
Nothing below is a repair instruction for this system. What follows is what to observe and record — the work itself belongs to a technician.
Most likely causes
Ordered by how often each one turns out to be the answer, with the tell that distinguishes it.
Safety interlock preventing deployment
most commonNo movement and no fault; ignition, parking brake or a door is in the wrong state.
Low battery voltage
commonPump attempts and stops, or sounds laboured.
Low hydraulic fluid
commonPartial extension, or some legs move and others do not.
Failed solenoid on one leg
commonA specific jack does nothing while the rest work.
Pump failure
less commonNo jack moves and the pump is silent or runs without pressure.
Corroded or seized jack after long standing
less commonFollows months of disuse, often outdoors.
What you can safely check
- 01
Never get under a coach on its jacks
Applies whichever direction they are refusing to move.
- 02
Check the interlock conditions
Ignition position, parking brake, door state. These vary by system and are the most common reason nothing happens at all.
- 03
Check battery voltage
Levelling pumps draw heavily, and an aborted deployment is often supply rather than hydraulics.
- 04
Note whether it is all jacks or one
One leg points at a solenoid or that cylinder; all of them points at the pump, fluid or supply.
What needs a technician
Solenoid, valve and pump work, hydraulic service, and cylinder repair. Fluid is checked at a defined jack position, and topping up at the wrong one overfills the system.
Parts typically involved
So you know what a quote should be naming. We publish no prices — real costs vary by market, season and technician, and a number we invented would look authoritative and help nobody.
- Hydraulic solenoid
- Hydraulic pump
- Jack cylinder or seal kit
- Level sensor
- Hydraulic fluid
- Control board
When to stop troubleshooting
- You are considering going underneath
- You are about to add hydraulic fluid without knowing the correct jack position for checking it
Can you still travel?
Retracted jacks are the travel position, so the coach drives normally. You will need to level with blocks or ramps until it is fixed, which is inconvenient rather than unsafe.
Common questions
- Is this as serious as jacks that will not retract?
- No, and the difference is mobility. Jacks stuck down make the coach undriveable and can strand you; jacks that will not come down leave you fully mobile and merely unlevel. You can travel, and you can schedule the repair rather than needing it now.
- Can I level with blocks in the meantime?
- Yes, and it is standard practice for coaches without powered levelling at all. Use proper levelling blocks or ramps rather than improvised materials, drive on gently, and chock the wheels. It is a genuine interim solution rather than a compromise.
Related failures
For the whole system rather than this one symptom, see RV leveling and jack repair.
Next step
Work through structured triage for this system and you will end up with a written service brief: what you observed, in what order, and what has not been established yet. It is the document that lets a technician quote properly instead of guessing on arrival.
Being straight about what this is. No technician is signed to any territory yet — not one. We do not match you, dispatch anyone, or promise a call. What you get is the brief, and a request form that copies it to us so we know the demand is real. If you need someone today, take the brief and send it to a local technician directly; it works just as well that way.