SA20 3 Ton Hydraulic Floor Jack Assembly & Operating Instructions 6
TROUBLESHOOTING
If Jack Will Not Lower Or Raise Load, check the following
1. Make sure jack is on level surface. Make sure oil level is properly added. Open release valve and step on
saddle. Force it to lower as rapidly as possible. Repeat this operation three or four times. This procedure will
thoroughly flush the valves and assure complete distribution of oil.
2. The jack may have air trapped in the system. Open release valve. Pump handle 6 full strokes. Close release
valve and try again.
3. O-ring seat for pump may be worn. This will happen only after months of service. A new o-ring seal or a
complete new piston can be purchased and installed.
4. Release valve may be held open by dirt on seat. Flush by pulling lifting arm up and down several times while
release valve is open. If necessary, the release valve may be removed for cleaning the valve and valve seat.
If Jack Lowers Under Load, check the following
1. The discharge valve may be held open by dirt on ball seat. When a dirty discharge valve or ball seat exists,
the jack may lower quickly, causing handle to fly back with force. This is caused by the oil rushing back into
the pump chamber and through the open ball seat. When this happens, it is advisable to repeat procedure 1
before going through the partial disassembly of the hydraulic unit. The discharge valve is located at the bottom
of ram cylinder. There is a screen washer which must be removed carefully. Remove the valve ball and clean
the valve seat. Wipe ball and replace and reseat. Use 1 / 4 “ diameter X3 long punch and small hammer. Place
punch on top of ball and give the punch a light tap. This will have the effect of reseating the ball on its seat.
Install the screen washer. Screw in ram cylinder tightly. Replace washers top and bottom of oil chamber.
Install ram assembly and screw in top nut.
2. Cup seat for the ram may be worn. This is likely only in jacks that have given very heavy service. Follow
above procedure until access to ram assembly is made. Remove worn seal by pulling away or cutting with a
small knife. Take caution not to damage the new ram seal when installing.
If Jack Will Not Lower Completely When Raised, check the following
1. Return spring for lifting arm bay be broken or unhooked. Replace return spring.
2. It may need lubrication. Clean and oil all moving parts in the lifting arm mechanism.
3. Hydraulic unit may contain too much oil and vent valve may be closed. Open vent plug.
If Jack Will Not Lift Full 3 Ton Capacity, check the following
1. The o-ring seal for piston pump may be worn.
2. The unit may have air trapped in the system.
3. The overload valve is factory adjusted for the jack to lift 3 tons load and should not be altered.
