Section II. MAINTENANCE AND REPAIR INSTRUCTIONS

TM 10-3990-200-12&P

Section II. MAINTENANCE AND REPAIR INSTRUCTIONS

IMPORTANT

c. Undercarriage pivot Pins. Add grease every

100 miles or at least every 6 months, at center of

Keep the Pump Release Valve Open at all

tubes (2) surrounding pivot-pins (2) Use Molyb-

times except when elevating the Ramp.

d e n u m Disulfide type of grease. Oil can points in

T o w i n g speeds

two places; 1. At pump handle socket pivot pins (2)

25MPH Max.-Primary and secondary

2. At upper and lower pivot pins on each hydraulic

roads

cylinder.

5MPH

Max.-Crosscountry

d. Tighten loose nuts and bolts.

I f wheel bearings are submerged under

2-6. Instructions For Mounting Tire and Rim

water

where

contamination

can

enter,

Assembly of Cast Spoke Wheels

remove and clean bearings immediately

a n d repack bearings with wheel bearing

a. Place rim on wheel with valve facing out and

grease.

halfway between two spokes. Make sure driver does

not ride on spoke ends.

2-5. Periodic Maintenance

b. P l a c e t w o c l a m p s i n p o s i t i o n o n a l t e r n a t e

spokes, side of clamp marked "Wheel" next to

a. Hydraulic System. If signs of a leak are found

spoke and side of clamp marked" Rim" next to rim,

or if there is a noticable decrease in pump pressure,

f l a t face of clamp out. Run nuts up snug against

CHECK PUMP FLUID LEVEL. TO CHECK

clamps so that clamps are in contact with wheel and

PUMP FLUID LEVEL-

rim (no torque). Place remaining clamps in position

( 1 ) Make certain RAMP is in lowered position

and run nuts up snug, as before.

with pump release valve OPEN so that fluid in

c. Starting with any spoke as number one using a

cylinders can be forced back into the pump.

torque wrench, tighten the nuts to 20 FP of torque

(2)

Remove

pipe

plugNOT

ACORN

each, in the following order--No. 1 -3-5-2-4.

NUTand with a clean stick check oil level through

C o n t i n u e around the wheel in the same order, in-

pipe plug hole. Refill to in. of top if level is below 4

creasing the torque each time around by 10 FP, until

inches from top.

all nuts are torqued to 90 FP.

(3)

Use

only

hydraulic

oil

MIL-H-5606

equivalent.

2-7. Check and Re-Torque All Clamps at 50, 150

(4) Replace pipe plug.

and 300 Miles

a. Under normal operating conditions, the clamps

Note

Pipe plug is a vented plug and if lost must

tend to seat themselves in the first 50 to 150 miles

be replaced with a vented plug or reduced

w i t h a noticeable drop in torque. To prevent slip-

pump output will occur.

page, all clamps m u s t b e c h e c k e d a n d n u t s r e -

( 5 ) To drain pump, disconnect hose at pump,

torqued to 90 FP after the first 50 and 150 miles of

o p e r a t i o n . To further insure against any loosening,

close pump release valve, actuate pump handle until

another torque check should be made at 300 miles.

all oil is removed. Refill per (2), (3) and (4) above.

b. Wheels.

b. E x c e p t i n c a s e s o f e x t r e m e o p e r a t i n g c o n -

(1) Check tire pressure as often as required to

d i t i o n s clamps should remain tight from this point

maintain 90 to 100 psi in both tires.

on, and require only an occasional visual check.

( 2 ) Once a year check wheel bearing for suf-

2-8. Repair Parts Installation for Hydraulic Hand

ficient grease. R e p l e n i s h o n l y w i t h W H E E L

Pump

BEARING

GREASE.

SPINDLE-NUT

(Fig. 2-1)

T I G H T E N I N G t i g h t e n with wrench, back off

Remove hydraulic pump from RAMP for all repairs.

w i t h wrench, hand tighten, line up groove in nut

Remove vented pipe plug from top cover and invert

with hole and apply cotter pin. Be sure dust caps are

p u m p until oil is drained. After repairs are made,

replaced.

c. Air Springs.

replenish oil in reservoir (% inch of top) and r e p l a c e

(1) Check tube pressure every 60 days or as

vented pipe plug.

often as necessary to maintain 45 to 55 psi in both

a. Pump Piston. (Fig. 2-1)

air springs.

( 1 ) Remove two pin rings 17 from pins 16 and

(2) Be sure valve stem caps are replaced after

19, pull pins from body and remove handle socket.

( 2 ) Remove packing nut 20. Insert pin 19 into

checking or adding air.

2-2