Never get under a load that is only
supported by a jack. Any jack is
subject to failure and personal injury
Safety is a very important factor in the use of jacks and
trestles and cannot be overemphasized. Often the
nature of their application makes them inherently
dangerous. Rated capacities should not be exceeded.
Jacks are usually lifting, pulling, spreading, or supporting
something which can become lethal if a mishap occurs.
Most accidents occur when the load is not stabilized.
These, devices are designed to exert force in one
direction,(through the center axis of the portion of the
jack which contacts the load.)
All jacks should be inspected prior to use, to insure they
are safe for the intended application. Check for rated
capacity, previous wear or damage and manufacturer
The following safety factors should be adhered to:
Keep fingers away from all moving parts.
When jacking up vehicles, make certain no one is
under the vehicle to be raised. Set the hand brake
firmly and block the front wheels if a rear wheel is
being changed. Block the rear wheels if a front
wheel is being changed. Place blocking or other
supports under the vehicle when it is raised to the
desired height to prevent it from dropping if the jack
Make certain that hydraulic jacks are filled with oil
and that there are no visible oil leaks before using.
Any new or repaired jack should be carefully
inspected by the operator prior to use.
Overloading can be hazardous to the jack, the
operating personnel, and the load in event of jack
Be aware of the capabilities of the jack, especially its
Special considerations for trestle safety:
Follow the instructions in the respective technical
methods of using trestles.
Insure the trestles are level, standing with all four
legs on a hard surface, and that the pawl is fully
seated, both before and after applying the load.
Insure the weight is distributed as intended.
Use trestles only in pairs.
Avoid shaking and bumping of the vehicle or load.
ALWAYS check to make sure all trestle legs are
firmly resting on the floor when the work area has
As many tires as possible should remain on the
vehicle, and on the ground.
Tires remaining on the ground should be chocked to
prevent movement, especially when loosening any
portion of the driveline.
Trestles supporting a load should not be used for
leverage while attempting to pry or pivot yourself or
a subassembly under a vehicle.
Trestles should be extended only as high as
A secondary support method, such as wood blocks,
a floor jack, A-frame, or crane should be used if
there is a question regarding the stability of a
maintenance procedure. DO NOT use a cut off 4x4,
6x6, or railroad tie that is standing on end. This is
extremely unstable and SERIOUS INJURY OR
DEATH may result. Wood blocks must be of
sufficient strength to support the load. Do not use
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