How do you lower a hydraulic trolley jack?

A hydraulic trolley jack is an invaluable tool for lifting heavy loads with minimum effort. Lowering a hydraulic trolley jack safely is just as important as raising it. Here are the steps to properly lower a hydraulic trolley jack.

Safety First When Using A Hydraulic Trolley Jack

Always follow safety precautions when using a hydraulic trolley jack:

Ensure the jack is on a solid, flat, level surface that can support the load.

Never get under the vehicle until it is supported by jack stands.
Do not exceed the weight capacity of the jack.
Do not move the vehicle while it is on the jack.

Wear closed-toe shoes to avoid foot injuries if the load slips.

Steps To Lower A Hydraulic Trolley Jack

Here are the steps to safely lower a hydraulic trolley jack:

Position the jack – Wheel the jack under the vehicle so that the saddle rests on the manufacturer’s recommended lifting point. This is usually on the vehicle’s frame rail or a reinforced jacking point.
Raise the vehicle – Use the jack handle to pump the release valve. Raise the vehicle high enough so that loaded jack stands can be placed underneath the manufacturer’s recommended support points.

Support the vehicle – Position jack stands under the support points. The load should be fully transferred onto the jack stands and not supported by the jack.
Loosen any lug nuts – Before lowering the vehicle, use the lug wrench to break loose the lug nuts of the wheel you plan to change. Don’t remove them fully yet.
Lower the jack – To lower, slowly turn the release knob counterclockwise. Lower the jack until the saddle clears the lifting point.

Remove the jack – Wheel the jack out from under the vehicle. Ensure no tools are left under the vehicle.
Perform maintenance task – With the vehicle safely supported on jack stands, you can now perform tasks like changing tires, servicing brakes etc.
Re-position the jack – When maintenance is complete, re-position the jack back under the lifting point. Ensure the saddle makes secure contact.

Raise the vehicle – Use the jack handle to raise the vehicle enough to clear the jack stands. Remove the stands.
Lower the vehicle – Slowly turn the release knob counterclockwise to gently lower the vehicle onto the ground.
Remove the jack – Once the vehicle is resting on its wheels, wheel the jack out from underneath.

Tighten lug nuts – If you changed a tire, fully tighten the lug nuts in a star or criss-cross pattern.

Lowering a jack takes time and should not be rushed. Always ensure support stands are holding the weight before lowering. Use smooth, controlled turns of the release valve to gently lower the vehicle.

Types of Hydraulic Trolley Jacks

There are a few common types of hydraulic trolley jacks:

1. Bottle Jack

Compact and lightweight but limited lifting height
Best for ordinary sedans and small vehicles

Lower cost than other jack types

2. Floor Jack

Low profile to wheel under vehicles
Long handle for added leverage

Higher weight capacity and lift height
Maneuverable with rear wheels

3. SUV/Truck Jack

Extended lifting saddles to match vehicle frame

Taller lifting height for high ground clearance
Robust construction for heavy use

How A Hydraulic Jack Works

Here are the internal components allowing a hydraulic jack to lift heavy loads:

Hydraulic Cylinder

Fluid-filled cylinder contains a piston, ram, and seals
Pumping the handle forces fluid through the valve into the cylinder
Fluid pressure pushes the piston, extending the ram and lifting the load

Release Valve

Valve controls fluid flow into and out of the cylinder
Closed when pumping to lift load
Open when turning release knob to lower load

Hydraulic Fluid

Typically jack oil that can withstand high pressures
Also acts as a lubricant reducing internal wear

Pump Piston

Sealed piston moved up and down by pumping handle

Creates suction that pulls fluid from the reservoir
Forces fluid into cylinder at high pressure when pushed down

Handle

Lever arm that is pumped up and down to operate piston

Increases force applied to fluid

Maintenance Tips For Hydraulic Jacks

Regular maintenance is key to ensure a hydraulic jack operates safely and reliably:

Check oil level monthly, top up with recommended hydraulic fluid as required

Replace hydraulic fluid at least once a year per manufacturer
Lubricate linkages and pivot points
Inspect lifting arm and saddle for damage or excessive wear

Check wheels and casters spin freely
Keep all surfaces clean from dirt, grease and debris
Follow manufacturer service schedule

Warning Signs Of Hydraulic Jack Failure

Stop using a hydraulic jack if you notice any of these signs of failure:

Difficulty pumping or jack feels springy – indicates air in system
Jack will not lift to full extension

Fluid leaks – signifies seal failure
Unusual noises when operating
Jack slowly drifts down under load

Cracked or damaged lifting saddle
Bent or broken lift arm
Loose or missing wheels or casters

A jack that shows signs of failure should be taken out of service and repaired by a qualified technician. Using a faulty jack could result in a vehicle falling unexpectedly and cause serious injury.

FAQs

Is it safe to use one jack stand?

No, you should always use jack stands in pairs to support a vehicle. As a rule of thumb, avoid working under a vehicle supported by only a hydraulic jack. Jack stands provide a more stable base.

How long can a car stay on jack stands?

Ideally no longer than 1-2 days. The vehicle’s suspension isn’t designed to bear weight in that position long term. For storage over 2 days, use ramps or remove wheels and lower the axle onto blocks.

Where should jack stands be placed?

Refer to the vehicle owner’s manual for the proper jack stand support points. Typically they are on the frame near front and rear suspension mounts. Ensure the stands clear brake lines, fuel lines etc.

Can you put a car jack on asphalt?

Yes, hydraulic jacks can be safely placed on asphalt. The base should be flat and level. Use wood blocks under the jack if needed to prevent settling into soft asphalt.

How much weight can a hydraulic jack lift?

It depends on jack construction but hydraulic bottle jacks typically handle 2-12 tons, scissors jacks 1.5-4 tons, and floor jacks 1-20+ tons. Never exceed manufacturer rated capacity.

Conclusion

Hydraulic trolley jacks allow controlled lifting and lowering of heavy vehicle loads with little effort. But improper use can lead to instability and collapse. Always support the vehicle with jack stands before working underneath. Inspect jacks before each use and follow the manufacturer’s maintenance schedule. With proper care, a hydraulic jack will provide many years of safe, dependable service.