Wheel Cylinder

(6) Position the boot (1) over the push rod

spring must be toward the outlet port end of the

end of the master cylinder and insert the push rod

cylinder bore.

(2) into the seat provided on the piston (6).

(3) Place the cup (7) in the cylinder bore and

(7) Install the gasket (16) and the filler cap

install the piston (6) and seal (5).

(15).

(4) Place the plate (4) and lock ring (3) over

e. Installation. Refer to TM 10-3930-624-12.

the push rod (2). Use the push rod (2) to push

4-12. Wheel Cylinder

against the piston (6). Install the plate (4) and

secure the parts with the lock ring (3). Make sure

a. Removal. Refer to TM 10-3930-624-12.

the lock ring seats securely in the groove provided

6. Disassembly. Remove the boots (fig. 4-201

in the end of the cylinder.

from the cylinder and push out the internal parts.

(5) Install the copper gaskets (13), the fitting

Low pressure air can be used at the inlet port to

(14), and the bolt (12) in the outlet of the master

assist in removal.

cylinder (17).

ME 3930-624-34/4-20

Figure 4-20. Wheel cylinder. exploded view.

c. Cleaning, Inspection and Repair.

the casting. Coat the cylinder bore with clean

(1) Use a lint-free cloth and clean the parts

hydraulic brake fluid. Follow the honing equip-

thoroughly in denatured alcohol or clean brake

ment manufacturer's instructions. Remove

fluid. Parts must be kept clean for reassembly.

material in single passes. After each pass, remove

Caution: Any solvents other than alcohol

the hone and inspect the bore to see if all blemishes

or brake fluid will deteriorate rubber parts,

have been removed. Remove only enough material

causing them to become soft, tacky and

to eliminate blemishes. If the cylinder bore is honed

swollen.

beyond the allowable tolerance, replace the

(2) Inspect all parts for wear, corrosion, or

cylinder. Original cylinder bow is 1.500 to 1.5070

damage. Inspect the cylinder bore. Pressure marks

inches.

and discoloration may be polished out with crocus

(5) After honing, remove the cylinder from the

cloth. (Do not use sandpaper or emery cloth.) Deep

vise and clean the cylinder thoroughly. Check to be

blemishes will require honing to resurface the

certain the ports are open and free of burrs which

might cause damage to moving parts.

cylinder wall.

(6) Replace the parts which are contained in a

(3) Make certain the ports are open. They

repair kit. Replace all other parts which are worn,

may be probed with a soft iron wire.

damaged, or corroded.

(4) If honing is necessary, secure the cylinder

d. Reassembly.

in a vise. BP careful not to tighten the vise ex-

cessively. This could distort the cylinder or crack

4-22