This document outlines the remove and replace procedures for the air compressor in HINO J08EVB & J08EVC engines. It provides detailed instructions for dismounting, mounting, disassembling, and assembling the air compressor, along with component identification and tightening torque specifications.

Function Description:

The air compressor is a critical component in the HINO J08EVB & J08EVC engines, responsible for generating compressed air. This compressed air is typically used for various pneumatic systems within the vehicle, such as air brakes, air suspension, and other auxiliary functions. The document focuses on the mechanical aspects of servicing this component, ensuring proper installation and operation.

Important Technical Specifications:

The document provides several key technical specifications, primarily related to tightening torques and dimensional tolerances:

Tightening Torque Unit: N-m {kgf-xm, lbf-ft}
- A: 29-34 N-m {296-347 kgf-xm, 22-25 lbf-ft}
- B: 25-29 N-m {255-295 kgf-xm, 19-21 lbf-ft}
- C: 23-26 N-m {235-265 kgf-xm, 17-19 lbf-ft}
- D: 30-36 N-m {305-367 kgf-xm, 22-27 lbf-ft}
- E: 23-26 N-m {235-265 kgf-xm, 17-19 lbf-ft}
- F: 2.5-3.9 N-m {26-39 kgf-xm, 1.9-2.8 lbf-ft}
- Mounting bolts for air compressor: 28.5 N-m {290 kgf-cm, 20 lbf-ft}
- Drive Gear lock nut: 142 N-m {1,450 kgf-cm, 105 lbf-ft}
Connecting Rod End Play:
- Assembly standard: 0.2-0.4 mm {0.008-0.015 in.}
- Limit: 0.5 mm {0.02 in.}
Crankshaft End Play:
- Assembly standard: 0-0.6 mm {0-0.0236 in.}
- Limit: 1.0 mm {0.0394 in.}
Piston Pin Removal Temperature: 80-90°C {176-194°F} for approximately 5 minutes.
Guide Stud Bolt: M8 x 1.25, length: 50 mm {1.968 in.} or more.

The document also includes a component locator, listing various parts of the air compressor assembly, such as:

Head cover, Gasket, Cylinder head, Valve seat, Suction valve, Unloader valve, O-ring, Cylinder liner, Piston ring, Piston, Connecting rod, Connecting rod bearing, Lock washer, Piston pin, Retainer ring, Bearing holder, Ball bearing, Crankcase, Crankshaft, Woodruff key, Coupling, Coupling bolt, Pin, Air compressor assembly, and Screw.

Usage Features:

The document primarily focuses on maintenance and repair procedures rather than operational usage features. However, it implicitly highlights the importance of precision and correct assembly for the proper functioning of the air compressor. Key usage-related aspects derived from the maintenance instructions include:

Alignment: Critical alignment marks ("0" on coupling flange with protrusion on compressor housing) must be observed during mounting to ensure correct engagement and prevent damage.
Lubrication: Engine oil must be applied to various sliding parts (connecting rod, cap, connecting rod bolt threads, piston pin) during assembly to ensure smooth operation and prevent premature wear.
Torque Control: Strict adherence to specified tightening torques is essential for all fasteners to prevent loosening, leakage, or damage to components.
Component Integrity: The document emphasizes careful handling of delicate parts like piston rings (due to their special casting) and the bearing holder (to prevent damage during pressing operations).

Maintenance Features:

The document provides a comprehensive guide for maintaining the air compressor, covering both removal and installation, as well as complete disassembly and reassembly.

Dismounting:

Remove Supply Pump: This is the initial step, indicating the supply pump must be moved to access the air compressor.
Remove Air Compressor: Involves removing six mounting bolts. A crucial "NOTICE" warns against excessive force to prevent damage to the mounting spigot or oil leakage from the liquid gasket.

Mounting:

Installation Procedures:
- Fit the No.1 cylinder to Top Dead Center.
- Align the "0" mark on the coupling flange with the protrusion on the compressor housing.
- Insert the O-ring into the groove on the bearing holder side.
- Use a guide stud bolt (M8 x 1.25, 50mm or more) for accurate positioning during installation.
- Tighten mounting bolts to 28.5 N-m {290 kgf-cm, 20 lbf-ft}.
- Verify alignment of the "0" mark.
Install Supply Pump and Air Compressor: This is the final step after the air compressor is securely mounted.

Disassembly:

Remove Drive Gear:
- Remove the lock nut from the compressor drive gear. A "NOTICE" warns that insufficient spread can damage the drive gear when loosening the nut.
- Pull the drive gear from the crankshaft and remove the woodruff key.
Remove Cylinder Head, Assembly, and O-Ring:
- Remove the cylinder head, assembly, and O-ring.
- Mark the head cover to the cylinder liner for correct reassembly.
- Do not decompose the cylinder head itself.
Remove Connecting Rod with Piston:
- Rotate the crankshaft to the top dead center.
- Spread the staking of the nut completely with a chisel before loosening.
- Remove the connecting rod with piston.
Remove Piston Rings:
- Remove the piston rings. A "NOTICE" advises careful handling due to their special casting and to arrange them for correct reinstallation.
Remove Piston:
- Remove retainer rings from both ends of the piston using pliers.
- Strike out the piston pin. A "NOTICE" recommends warming the piston in hot water (80-90°C for 5 minutes) to ease piston pin removal.
Remove Crankshaft:
- Remove the bearing holder fitting screw.
- Use a press to remove the crankshaft with the bearing holder. A "NOTICE" warns against damaging the bearing holder.
Remove Bearing Holder:
- Use a press to remove the bearing holder. A "NOTICE" warns against damaging the bearing holder.
Remove Ball Bearing:
- Use a special tool to remove the ball bearing from the crankshaft end.

Assembly:

Install Ball Bearing: Install the ball bearing onto both ends of the crankshaft.
Install Crankshaft:
- Use a press to install the crankshaft to the bearing holder.
- Install the crankshaft and bearing holder into the crankcase.
- Tighten the bearing holder fitting screw.
Install Connecting Rod and Measure End Play:
- Align the aligning mark.
- Apply engine oil to the connecting rod, cap, and bolt threads.
- Measure connecting rod end play (standard: 0.2-0.4 mm, limit: 0.5 mm).
- Lock the nut with a lock washer.
Measure Crankshaft End Play: Measure crankshaft end play (standard: 0-0.6 mm, limit: 1.0 mm).
Assemble Piston: A "NOTICE" emphasizes applying engine oil to all sliding parts.
Assemble Piston and Connecting Rod:
- Warm the piston in hot water (80-90°C for 5 minutes).
- Install retainer ring at one end of piston pin holes.
- Apply engine oil to the piston pin.
- Fix piston and connecting rod by inserting the pin.
- Fit a new retainer ring at the other end.
Install Cylinder Liner and Cylinder Head:
- Rotate crankshaft to top dead center.
- Arrange piston rings with equally spaced gaps.
- Install cylinder liner and cylinder head. A "NOTICE" warns against twisting the O-ring during installation.
Install Drive Gear:
- Install the woodruff key to the crankshaft.
- Insert the drive gear.
- Insert the collar and lock nut.
- Tighten to 142 N-m {1,450 kgf-cm, 105 lbf-ft}. A "NOTICE" advises applying oil to threads and seat surface before tightening.

The document is structured to guide a technician through each step of the air compressor service, ensuring proper technique, lubrication, and torque application for a reliable repair. The repeated "NOTICE" sections highlight critical steps and potential pitfalls, emphasizing the importance of careful execution to prevent damage and ensure longevity of the component.

Hino J08EVB - Page 2