Isuzu N-Series. Manual - part 232

HYDRAULIC BRAKES 5A-87

10. Install the return spring (1).

Install the closed hook of return spring to pin side.

11. Install the piston (1).

Apply grease to the outer circumference of piston
and groove of piston cup (2), and install the
grease-applied piston cup.

12. Install the boot (1).

Apply grease to the boot installation groove of cyl-
inder, fill the grease to inside of boot and install it.

Grease: BESCO rubber grease

13. Install the bleeder (1) to cylinder assembly (2).

Tighten:
Bleeder to 6.9 — 11.8 N

⋅m (0.7 — 1.2 kg⋅m / 5.1 — 8.7

lb

⋅ft)

1

N5A0459E

1

2

N5A0460E

1

N5A0461E

1

2

N5A0462E

5A-88 HYDRAULIC BRAKES

Master Cylinder Assembly (NHR)

Disassembly

1. Hose Clamp
2. Hose Joint

Use a pair of pliers to remove the hose joint.
Take care not to damage the hose joint and the cyl-
inder body.

3. Stopper Screw and Gasket 
4. Snap Ring
5. Primary Piston Assembly

Legend

1. Hose clamp

5. Primary piston assembly

2. Hose joint

6. Secondary piston assembly

3. Stopper screw and gasket

7. Cylinder body

4. Snap ring

N5A0266E

N5A0267E

HYDRAULIC BRAKES 5A-89

6. Secondary Piston Assembly 
7. Cylinder Body

Inspection and Repair

Make the necessary adjustments, repairs, and part re-
placements if excessive wear or damage is discovered
during inspection.
Cylinder Body

Visually check that the master cylinder bore, for scuff or
scratch, if these conditions are presented, the cylinder
body must be replaced.
Piston and Master Cylinder Clearance

1. Use a micrometer to measure the piston diameter.
2. Use an inside dial indicator to measure the cylinder

bore.

3. Calculate the clearance between the wheel cylin-

der and the piston.
If the clearance exceeds the specified limit, the pis-
ton assembly must be replaced.

Reassembly

1. Cylinder Body

Clean the cylinder body and blow the return ports
with compressed air.
Do not allow the return ports clogged with any for-
eign material.

2. Secondary Piston Assembly

Piston and Master Cylinder Clearance

mm (in)

Standard

Limit

0.11 — 0.195

(0.004 — 0.008)

0.22 (0.009)

N5A0268E

N5A0269E

N5A0271E

5A-90 HYDRAULIC BRAKES

3. Primary Piston Assembly

1) Rinse the piston assembly in clean brake fluid.
2) Install the piston assembly to the master cylin-

der.

Notice:
Take care not to scratch the primary and secondary
cups when installing the piston assembly.

4. Snap Ring
5. Stopper Screw and Gasket

1) Slide the piston until the oil cavity of the sec-

ondary piston dears the stopper bolt hole.

2) Install the stopper screw and tighten it to the

specified torque.

Tighten:
Stopper screw to 27 N

⋅m (2.8 kg⋅m / 20 lb⋅ft)

6. Hose Joint
7. Hose Clamp

1) Set the clamp in position.

2) Dip the hose joint in hot water (60 — 80

°C / 140

— 176

°F) for several minutes.

3) Take out of the hose joint and blow off water im-

mediately and completely.

4) Fit the hose joint to the cylinder body.
5) Align the position of the clamp screw as shown

in the illustration.

6) Tighten the clamp screw to the specified

torque.

Tighten:
Clamp screw to 2 N

⋅m (0.2 kg⋅m / 17 lb⋅in)

N5A0272E

N5A0273E

N5A0274E