Air Spring Assembly

TM 10-3990-203-13&P

5.5.9 Hydraulic System (Figures 5-10 and 5-11)

c. Place washer (3) over the end of bolt (l).

d. Thread locknut (4) onto the end of bolt (l).

5.5.9.1 Hydraulic Pump

Tighten by hand.

5.5.9.1.1

Disassembly

e. Use a 1/2 inch socket with ratchet on bolt head

(1) and a 1/2 inch box wrench on locknut (4) to tighten

a. Place a 3/4 inch open end wrench over hy-

the assembly securely.

draulic hose coupling (9, Fig. 5-10). Disconnect

hose from pump body (1, Fig. 5-11).

f. Continue this procedure until all the holes in

the I-beams are used, securing the grating in place.

b. Place a 9/16 inch socket and ratchet over pump

mounting bolts (10, Fig. 5-10). Loosen and remove

5.5.8 Air Spring Assembly (Fig. 5-9)

bolts.

5.5.8.1

Disassembly

c. The hydraulic pump can now be removed from

under the ramp.

a. Place a 9/16 inch box wrench over locknut (4)

and a 9/16 inch socket with ratchet over air spring

d. Insert a 3/16 inch allen wrench into screw

Loosen and remove all

mounting bracket bolt (3).

head (4, Fig. 5-11). Loosen and remove four screws.

four locknuts and bolts.

NOTE

b. The air spring assembly can now be removed

from underneath the ramp.

When reservoir screws (4) are loosened the

hydraulic fluid will begin to drain. Capture

c. Place the 9/16 inch socket with ratchet over

this fluid and discard properly.

air spring mounting bolt (2). Loosen and remove both

bolts.

e. Remove reservoir (2) and o-ring (3).

d. Remove air spring hanger (1) from air spring

f. Straighten and remove cotter pin (38).

(5).

g. Remove washer (39) and beam link pin (37)

e. Use a 9/16 inch open end wrench to remove

from beam (34).

valve stem (6).

h. Remove wave washers (41).

f. Refer to the parts list for replacement parts.

i. Pull up on beam (34) to extract plunger (44).

5.5.8.2

Reassembly

NOTE

a. Thread valve stem (6) into air spring (5) and

secure using a 9/16 inch open end wrench.

Unless replacing the beam or plunger, these

parts can be left attached to each other.

NOTE

j. Remove wiper (45), backup ring (46), and o-

Valve stem (6) should be in the upward posi-

ring (47). O-ring can be pried out with a small

tion.

screwdriver or pick.

b. Align the holes in air spring hanger (1) with

k. Remove cylinder (48), o-ring (49), backup

the holes in the top of air spring (5).

ring (50), o-ring (51), and ball (52).

c. Insert air spring mounting bolts (2) through

1. Insert a 9/64 inch allen wrench into capscrew

hager (1) and thread into air spring (5).

(28). Loosen and remove capscrew and washer (29).

d. Place a 9/16 inch socket with ratchet over

m. Pull up on and remove spool (7).

bolts (2) and tighten securely.

n. Remove o-rings (8, 9, and 10) from spool (7).

e. Align the four holes in air spring hanger (1)

with the hanger mounting holes in the frame.

o. Insert a 1/8 inch allen wrench into orifice

screw (11). Loosen and remove screw.

f. Insert mounting bracket bolts (3) through the

holes.

p. Remove wiper (12).

g. Thread locknuts (4) onto the ends of bolts (3)

q. Insert a 1/8 inch allen wrench into the top of

and tighten by hand.

setscrew (5). Loosen until lever (6) can be extracted

from spool (7).

h. Place a 9/16 inch box wrench over locknuts

(4) and a 9/16 inch socket with ratchet over bolt heads

r. Remove breather plug (13).

(3) and tighten securely.

5-12