Motorcycle Jack Won’t Stay Up | Here’s Why (SOLVED)

It’s your day off, and you invite your buddy to meet at your place for a moto rip and a river dip.

You’ve got a few hours to kill before he frees up, so you figure you’ll change the oil quickly before he shows up.

You grab your trusty hydraulic motorcycle jack, but it’s stuck in the down position.

You pump and pump, but nothing happens, or maybe it goes up until you slide it under your bike, and it keeps falling. Either way, why won’t your motorcycle jack stay up?

Read on to find the answer.

Here’s Why Your Motorcycle Jack Won’t Go Up:

A jack that won’t go up might be the wrong one for your bike. Check the lift capacity to ensure the jack is suited for your bike’s weight, inspect your hydraulic fluid levels, bleed any air from the hydraulic system, and examine the jack’s seals and the condition and position of its release valve. 

Inadequate Lifting Capacity

Various motorcycle jacks are intended for use with motorcycles of a specific weight class.

Furthermore, there are myriad types of bikes these days, all of which break down into various categories of engine displacement, frame size, and overall wet and dry weight categories.

A jack that worked great on your Honda CB500 Cafe Racer isn’t necessarily equipped to handle your 850-pound, tour-stocked bagger.

If your motorcycle jack won’t stay up, the first thing to do is inspect the jack’s lift capacity. Attempting to lift a bike that exceeds the lift rating of our motorcycle jack will prevent the jack from holding the pressure it needs to stay elevated.

  • I’ve seen it go down—the jack starts to lift just fine until it starts to feel the pressure of the weight of the motorcycle’s frame.
  • The jack will start to take on the bike’s weight and continue to lift with no problem while sharing the load with the tires.
  • In some cases, once the tires start to lift off the ground and the full load of the motorcycle’s weight shifts onto the jack’s lifting surface, the motorcycle jack appears as if it won’t elevate.
  • In other situations, the jack takes on the weight enough to suspend the bike’s wheels into the air, but as soon as the home-moto-mechanic tries to pump, the jack drops down, and the wheel of the bike hits the ground.

This may seem like a prominent item, but we started with it for a reason.

This is more than just the most fundamental reason a motorcycle jack won’t stay up; attempting to lift a motorcycle that’s too heavy for the moto jack’s rating is the root cause of many of the other reasons listed below.

We suggest inspecting your motorcycle jack’s lifting capacity before attempting to lift your motorcycle, cross-referencing it with your motorcycle’s wet weight to be sure your bike isn’t too heavy for the jack. 

If you’ve already tried to lift your bike with an insufficient jack, don’t sweat it—just get your bike safely on the ground and get yourself a jack with a higher weight capacity.

However, before you stash the current jack you’re using, you may want to scroll down the list and check out a few other items.

If you continuously attempt to lift a motorcycle with a jack that can’t handle the bike’s wet weight, you’re risking damage to the seals and potentially causing internal fluid leaks.

If you damage the seals and cause fluid leaks, your motorcycle jack won’t hold pressure or stay lifted, even while attempting to lift a lighter bike within its capacity range.

Read on to find out how to inspect the critical components of your motorcycle jack and troubleshoot its ability to hold air and lift your motorcycle.

Leaking or Contaminated Release Valve

If your hydraulic motorcycle jack’s release valve develops a leak, whether from lifting a bike beyond its capacity or just from the wear-and-tear of long-term use, your motorcycle jack won’t stay elevated because it won’t hold pressure.

The release valve needs to be holding fluid airtight. Otherwise, it lets pressure out with every crank and allows air to backflow into the hydraulic system.

A leaky value often reveals itself by developing a greasy, grimy layer of film around the valve’s seal, which is sure evidence your release valve leaks.

  • Some motorcycle jacks don’t have screw motion release valves as the traditional jacks did.
  • In contrast, some of the newer motorcycle jacks use a foot lever-controlled release valve.
  • If the foot valve pumps the jack-up under no weight, the pump is working and therefore not the issue.
  • Therefore, on these types of motorcycle jacks, you move on to opening the control valve as if you’re lowering the jack stand and then pumping the foot pedal several times (while the jack is NOT underneath a weight load of any kind).
  • This will flush any foreign objects out of the valve.

On foot pump motorcycle jacks, your release valve may not be leaking, just contaminated; if dirt is interfering with the spring or ball seat inside your valve, it can prevent your jack from building pressure and staying up. 

  1. Depending on the brand and model jack you’re using, your motorcycle jack should have a plug or cap somewhere around or on the cylinder pump.
  2. Pull off the plug or cap, and you’ll find a ball and spring set up. Inspect for dirt, debris, gravel, etc., as this is enough to interfere with the jack’s ability to hold pressure.
  3. Clean anything foreign out of this system, restore it to how you found it, and plug it back up to see if a contaminated release valve is why your motorcycle jack can’t stay up.

Blown Hydraulic System Seal

This is similar to the section directly above,  so we won’t spend too much time on it.

If a seal anywhere in your motorcycle jack’s hydraulic system is blown, whether from straining the jack by overloading it or general wear-and-tear over time, the motorcycle jack won’t stay lifted.

Simply put, hydraulic jacks build pressure via a fluid system in a pressurized, vacuum-sealed chamber. As the fluid enters the chamber, it creates pressure and lifts the jack’s load-bearing surface.

If the seals that keep the system airtight are impaired, even slightly, the system is no longer vacuum sealed, and its ability to pressurize is compromised.

Once the system can’t hold pressure, the motorcycle jack won’t lift your bike,

Even if the jack lifts your bike at first, the jack won’t be able to hold the pressure while under load; the jack won’t stay up for long.

Related: Motorcycle Won’t Start With Kickstand Down | Here’s Why (SOLVED)

Trapped Air Needs to Be Discharged

It only takes a tiny bit to interfere with your motorcycle jack’s ability to lift and stay elevated.

It’s essential to examine your motorcycle jack before attempting to lift your bike with it, bleeding the air out of the system and removing air bubbles before attempting to lift your precious cargo.

On traditional hydraulic motorcycle jacks, bleeding the air is straightforward:

  1. Crank the release valve in the counterclockwise direction.
  2. Take the oil fill screw out of the lifting mechanism.
  3. Return the release valve to its starting position.
  4. The process should have forced the trapped air out of the oil fill hole, and your motorcycle jack should hold pressure and stay up like new.
  5. If the jack won’t stay up, repeat the air bleeding process a few more times, as removing all the air from your pressure system often takes a few rounds of pumping and releasing.

Note: If you have air in your jack’s hydraulic pressure system, there’s a leak somewhere; if the system were correctly sealed, the air wouldn’t have had an entry point. 

Review the previous two sections to track down your motorcycle jack’s pressure leak.

Related: My Motorcycle Tires Won’t Bead? Here’s Why (SOLVED)

Improper Fluid Levels and Condition

Your motorcycle lift won’t function properly if its fluid levels are too high or too low.

Your motorcycle jack comes with manufacturer operating instructions, including the spec hydraulic fluid level that needs to be maintained; if the levels are off in either direction, it can make it so your motorcycle jack won’t stay up under pressure.

If the jack has too much hydraulic fluid, the excess fluid allows for extra pressure. The excess pressure can blow seals and cause leaks that interfere with the jack’s ability to hold pressure under any weight load, even while under-loaded.

In contrast, a moto jack that has less fluid than the spec calls for will start lifting just fine but won’t be able to achieve its typical height. This could be why your motorcycle jack won’t lift high enough to keep your bike in the air.

Hydraulic fluid systems are a vacuum-sealed closed loop, meaning that if the fluid is low, filling it won’t be enough to restore the jack’s maximum height and weight capacity; you’ll have to figure out how the fluid escaped.

Consult the first few sections for tips on troubleshooting the jack for leaks. In the meantime, here’s how to check the hydraulic fluid level in a motorcycle jack:

  • Remove the fluid fill plug or cap.
  • Inspect the inner fill chamber, and you’ll find a fill line.
  • If the fluid is filled to spec, check its condition. If there’s dirt and debris inside, you may have a weak point in the seal that’s letting in first and air, and that’s what’s causing your lifting issues.
  • If the fluid is above the line, your jack’s hydraulic oil is overfilled and is likely preventing it from staying lifted; inspect its seals to ensure you haven’t blown any.
  • If the fluid level is lower than usual, top it off. Inspect the rest of the hydraulic system thoroughly to find the oil’s escaping point.

To be clear, different types of motorcycle jacks work differently. We can’t stress enough the importance of consulting your owner’s manual before checking the oil and fluid levels; there’s likely a troubleshooting guide that’s specific to your make and model motorcycle jack that includes instructions for fluid levels and conditions.

It also includes the type of hydraulic fluid your jack uses. This is essential information, as there are various types of hydraulic fluids, some of which have different ratings and subcategories.

Using the wrong type of hydraulic fluid can prevent your motorcycle jack from staying up just as quickly as using too much or too little fluid will.

Furthermore, be sure you’re not using compressor oil or engine oil, as these oils don’t have the additives needed for pressurization in your particular system.

In addition, these other oil types can cause damage to the lines and seals and might cause leaks that will make it so your motorcycle jack won’t stay elevated.

Garagespot.com says that you can use automatic transmission fluid in an absolute emergency. However, we suggest you flush and detail clean your hydraulic system as soon as you finish the task at hand, refilling it with the OEM-recommended hydraulic fluid listed in your jack’s manual.

Sources

Garage Spot | How To Repair A Floor Jack

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