Polish the flat surfaces of the metering section of the control valve.

(4) Make alinement marks on the mounting

centering disc (41). Push the centering spring (42)

plate (36) and the column flange (22) to ensure

out of the spot in the spool (43).

correct reassembly. Remove the capscrews (13)

(17) With a small bent tool or wire, remove the

and clips (14) securing the column (22) to the

seal ring (45) and seal plug (46) from the housing.

mounting plate (36) and separate the two

Do not pry against the edge of the hole in the

housing bore.

assemblies.

(5) If service of the column is necessary,

(18) Clamp the housing in the vise, control end

disassemble.

up. Unscrew the check valve seal (47) with a 3/16

(a) Remove the retaining ring (15) and the

in. hex wrench. Remove the housing from the vise.

(19) Turn the housing over and with the check

first snap ring (16). Push the shaft (19) free of the

valve hole toward the lowest corner, tap it lightly

tube (22) with thumb pressure.

(b) Remove the bearing (17) and remaining

with the palm to remove the check valve seat (47),

ball (48). and spring (49) from the housing (50).

snap ring (18).

d. Cleaning, Inspection and Repair.

(6) Remove the contact ring (20) and the

(1) Carefully clean the parts with a suitable

insulator (21) from the tube and flange (22).

solvent and allow them to air dry. Place the parts

Remove the seal (23).

on clean paper towels. Be careful not to use any

(7) Remove the capscrews (24), horn brush

rags which have loose lint or threads,

assembly (25). lead (26). and connector (27).

(2) Inspect the surfaces of all moving parts for

(8) With plugs in the ports of the valve unit,

scoring, excessive w e a r , o r damage. Smooth

clean the exterior with a wire brush to eliminate the

burnished surfaces are normal in many areas. Do

possibility of paint or dirt particles getting inside

not mistake this condition for excessive wear.

the unit.

(3) Slightly scored surfaces can be cleaned up

(9) Remove the plugs and clamp the valve unit

by hand rubbing with 600-grit abrasive paper.

in a vise with the meterity end up. Use a smooth

Replace any defective or excessively worn parts.

jawed wise or use sheets of soft metal on the jaws to

Replace all seals with new seals.

protect the valve unit surfaces. Remove the cap-

(4) Polish the flat surfaces of the metering

screws (28) which secure the cap (29) and the gear

section of the control valve.

plate and drive assembly.

(a) Place a piece of 600-grit abrasive paper

(10) Remove the cap (29) and the spacer (30).

face up on a piece of plate glass or a similar smooth,

Remove the gear plate and drive assembly from the

flat surface.

valve housing (50). Remove the rotor ring gear

(b) Clean the ends of the rotor by stroking it

(31). the rotor (32). and the plate (33) from the

across the abrasive. This will also remove any sharp

drive (34).

grit which could scratch other components.

(11) Remove the control unit from the vise and

(c) Lightly clean up both sides of the ring

check for free rotation of the control spool and

gear, both sides of the plate, the 14-hole end of the

sleeve parts with the steering column shaft.

housing, and the flat side of the end cap. Stroke

(12) Place a clean wooden block across the

each surface across the abrasive severaI times and

vise throat to support spool parts and clamp unit

check the results. Any small bright area indicates a

across port face with control end up. Remove the

burr, which must be removed. When polishing the

capscrews (3.5) which secure mounting plate.

parts, hold them as fiat as possible against the

(13) Hold the spool assembly down against the

abrasive. After 6 to 10 strokes across the abrasive,

wooden block and lift off mounting plate (36).

check the part to see if it is polished.

(14) Remove the seal (37) and the mounting

(d) After each part is polished. rinse it clean

plate locator bushing (38). Remove seal (39).

in solvent, dry it with compressed air, and place it

(15) Place the port surface of the housing

w h e r e i t w i l l remain absolutely clean for

secureIy on a solid surface and remove the spool-

reassembly.

sleeve assembly (40-44) from the 14-hole end of the

e. Reassembly.

housing.

(1) Lubricate all of the parts lightly with clean

Caution: Use extreme care when

hydraulic oil.

removing these parts, because they are very

(2) Install the housing (50, fig. 4-27) in a vise

closely fitted and must be rotated slightly as

with the control end up and the 14-hole end resting

they are withdrawn.

on a clean wooden block. Clamp it lightly across the

(16) Remove the centering pin (40) from the

port surface and install the check valve spring (49)

sleeve (44). Push inside the lower edge of the spool

into the bore with the large end of the spring down.

(43) to move it toward the splined end and remove

the spool carefully from the sleeve. Remove the

4-30