Remove shock absorber from car.
Place instrument in clamp and tighten the wing nut. (See Fig 1101).
Remove filler plug.
With the reservoir lock ring wrench, turn the cover lock ring 1⁄4 turn to the left, to relieve ring tension. (See Fig. 1102).
To remove reservoir cover, place the reservoir cover wrench in the position shown in Fig. 1103 and turn toward the left.
Remove reservoir cover and shaft gasket and lift off rubber gasket from reservoir. (See Figs. 1104 and 1105).
Check the air vents and replenishing valve. (See Fig.1107). This is done by screwing down the needle valve until it seats and placing the square end of flange cover and wing shaft wrench over the wing shaft as shown in Fig. 1106 and pumping the instrument several times. If the instrument is working properly, the fluid will be forced out of the air vents and the replenishing valve will draw in air. This operation will also help to clean out the air vents.
Unscrew needle valve using combination needle valve and packing nut wrench for this purpose. (See Fig. 1108).
Needle valve assembly can then be with- drawn from wing shaft. (See Fig. 1109).
It is very important that the same flange cover be replaced and that it is reassembled in the same position with relation to the base of the in strum en t. If more than one instrument is being dismantled at the same time extreme care must be taken not to mix any of the parts. This is important so as to avoid any possibility of obstructing the replenishing valve in the flange cover. As a guide when reassembling the instrument, locate the setting of the flange cover in relation to the base of the instrument by marking it with a small chisel. (See Fig. 1110).
Remove flange cover by turning cover to the left. The thick end of the flange cover wrench is used for this purpose. (See Fig. 1111).
In removing the rotating wing, observe position of lever bolt notch in wing shaft in relation to the stationary wing. When re- assembling replace wing shaft in same position. Do not attempt to remove the stationary wing.
Drain the remainder of the fluid in the instrument (see Fig. 1113) and thoroughly wash all of the parts in denatured alcohol. If an air line is available, it should be freely used especially in the air vents (see Fig. 1107).
After the parts are completely dry, place instrument in clamp and reassemble the wing shaft in its original assembly position using the same wing shaft. (Wing shafts are fitted in the instruments by selective fit and are not interchangeable). The only new parts you will use in the reassembly of the instrument is the A-22443 reservoir gasket and the A-18043-B packing ring and possibly a new needle valve assembly. Use the fluid gun and replenish fluid up to top of wing shaft. (See Fig. 1114).
Assemble instrument by reversing instructions given for disassembling. Use a new cork gasket and rubber gasket and replace needle valve assembly if the packing has been damaged. Replenish the auxiliary reservoir up to the level of the opening of the filler plug (see Fig. 1115). To force out any air, place the square end of flange cover wrench over end of wing shaft and pump the wing shaft a few strokes with needle valve closed.
The instrument should now be placed on the test fixture and tested and adjusted as described under Fig. 1116.
Spring hangers, connecting links and springs must be lubricated regularly (see lubrication chart in Instruction Book) to obtain 100% shock absorber performance. Also see that the shock absorber are filled to the proper level with fluid that the lever arm bolt nut is drawn tight (see Fig. 1098.) If this nut is loose the instrument becomes noisy.
Please refer to Fig. 1079 in the January Service Bulletin regarding the installation of side wheel carrier and change the 17 29/32” dimension to read 7 29/32” This dimension applies to both the 131 1⁄2″ and the 157″ truck chassis.
The valve numbers on page 529 in the January Bulletin were transposed. The new special alloy cast valves for the exhaust are carried under A-6505-Al. The valves used in the intakes are carried under A-6505-A2. Please correct your copy of the Bulletin.