• Typical Seal Kit Components for Weaver 2, 4, 10 & 20 Ton Service Jacks

To Remove The Cylinder:

1. Remove the cotter pin (pins) or bolts in the cross head.

2. Remove the cotter and pin in the pump.

3. Remove the cotter and pin in the release yoke.

4. Place cotter key in while depressing foot pedal.
This allows for easy removal and reassembly if spring is left on return rod.

5. Raise the lifting arm by means of the saddle bracket, and place a block of wood between the arm and frame to hold up the arm.

6. This releases the cylinder at the forward end, so that it may be removed as a complete unit, for service.

To Replace The Piston Ram Cup: 

1. After removing the cylinder unit as described above, place it in a vise. Note that the vise jaws should grip the steel block, not the steel cylinder. Set the unit in the vise with the steel cylinder and piston up. Remove the vent plug.  Drain the oil.

2. Remove the Packing Nut [A] and three Packings [B] .Unscrew the cylinder cap [C] and lift the piston out of the cylinder.

3. Remove the nut [I], Lock Washer [H], and washer [G] which holds the cup [F] at the end of the piston--put in the new cup [F], and replace the nut and washer.  (The Backup Teflon Ring [E] is only used on certain – but not all WA-75A models only)   Either peen the threads with a punch or use a thread locking compound to prevent nut from loosening.

4. In fitting the new cup into the cylinder, USE GREAT CARE as the cup passes the filler plug hole not to cut or otherwise damage the cup.  Lubricate the cup with hydraulic oil when assembling.

5. Replace the Cylinder Cap [C] and Gasket [D] -- install the 3 new Packings [B]   and the Packing Nut [A].

CAUTION

Excessive friction, chatter and binding will occur if the cup nut is pulled down too tightly.

TIP This means that you use only enough pressure to close the spring lock washer [H].  Do not tighten until the cup heel begins to extrude (swell) as this may cause problems

When servicing a jack with a synthetic cup, it may appear that the nut has become loosened, but this is not necessarily true. It is only necessary to hold the cup against the ram with slight pressure to prevent leakage.

To Replace The Pump Cup (small cup):

1. Turn the cylinder unit pump end upward in the vise.

2. Unscrew the packing nut [M] - Remove three Packings [L] and pull out the pump plunger.   Remove the Nut [J] that holds Cup [K] to the end of plunger; insert new cup, new packings and replace the nut and washers. 
3. Lubricate the cup with hydraulic oil when reassembling.  Either peen the threads with a punch or use a thread locking compound to prevent the nut from loosening.

Ball Valve Replacement:

1. Remove the Ball Chamber Plug [V].  Remove the Two Balls [X&Z] and the Ball weight [Y].

2.  Reassemble with the two new Balls [X&Z], New Plug Gasket [W] and Ball Weight [Y] (reuse the existing Ball weight).  Ball Weight is installed between the two balls.

IMPORTANT: Whenever it is necessary to loosen or remove the Ball Chamber Plug, the Gasket [W] should be replaced with a new one. Oil leakage at this point is usually caused by trying to reuse an old gasket over again.

Release Group Needle Valve Packing “O” Rings Replacement:

1.  Measure accurately the distance from the Bracket [O] to the first Nut [P] on the compression spring. Write this measurement down. (This is approximately 2 inches)

2.   Loosen the Packing Nut [R].  Remove Nuts [P] & [Q], the Spring, the Valve Rod [N] , the Valve Guide [OO] and the Packing Nut [R].  It is not necessary to remove the rod clevis.

3.  Remove the Packing Housing [S] and replace the two “O” rings [T&U].  Now reinsert the Packing Housing [S].  Reassemble the Needle Valve and parts with the Packing Nut [R] tightly secured.

4. Tighten the adjusting nut [P] to the original dimension that you wrote down and lock this nut with Nut [Q].

Release Group Needle Valve Adjustment:

In the release group assembly, the spring governs the load that the Jack will lift.  When the pressure within the cylinder overcomes the spring tension then the release valve floats off the seat.  It is Imperative that the release valve floats freely in the release group assembly. To check- use your forefinger and thumb to grasp the release valve where the release clevis pin passes thru, and wiggle from side to side. There should be a minimum of .002 to.004 clearance in the Release Vale Guide [OO]. If no movement is noted, follow these steps:

Refer to above Diagram

Measure accurately the distance from the Bracket [O] to the first Nut [P] on the compression spring. Write this measurement down. (This is approximately 2 inches)

Remove Nuts [P] & [Q], the Spring, the Valve Rod [N] and the Valve Guide [OO].  It is not necessary to loosen the Packing Nut.

Next, insert the Valve Rod [N] thru the Bracket’s [O] opening, slide the Release Valve Guide [OO] onto the rod, but not seated in the hole, and insert the rod [N] into the Packing Nut’s [R] opening.

Gently Tap the end of the release rod [N] with a hammer until it stays firmly seated in the internal needle seat.  Slide the Release Valve Guide [OO] towards the Bracket [O] (normally it will smoothly fit into the bracket hole) and then noting where the center alignment of the rod in the bracket hole is off -- Tap the welded bracket accordingly with a hammer to gently bend the bracket and correct the misalignment. It is in alignment when you can smoothly slide the Valve Guide into the Bracket’s hole.

Reassemble the Release Valve and parts.  Tighten the adjusting nut [P] to the original dimension that you wrote down and lock this nut with Nut [Q] and then test the Jack for proper operation.