Heavy Truck Maintenance and Refurbishment Guidelines for Used Chinese Trucks

Introduction

Based on our experience in used Chinese heavy truck refurbishment and overseas export preparation, proper inspection and timely replacement of wear parts are important to reduce unexpected breakdowns after delivery.

The following maintenance recommendations apply mainly to popular Chinese heavy trucks such as SINOTRUK HOWO 371HP, HOWO TX/NX series and similar heavy-duty trucks used for transportation, construction and mining operations.

The mileage intervals below are reference values under normal highway working conditions with standard loading. For trucks operating in Africa, Middle East, mining areas, construction sites, mountainous roads or high-temperature and dusty environments, inspection and replacement should usually be carried out 20%–30% earlier depending on actual working conditions.

1. Engine, Cooling and Air Intake System

Engine Oil and Oil Filter

Normally replace engine oil and oil filter every 10,000 km or 6 months, whichever comes first.

For trucks working in high-temperature, dusty or heavy-load environments, we recommend shortening the maintenance interval to around 7,000–8,000 km to protect engine performance.

Fuel Filters

Primary and secondary fuel filters should normally be replaced every 20,000–30,000 km.

Poor-quality fuel is common in some overseas markets, so fuel system inspection is especially important before export delivery.

Air Filter

Air filters normally require replacement around every 20,000 km under highway conditions.

For African mining areas, construction sites and dusty roads, the filter should be checked more frequently. A blocked air filter can reduce engine power, increase fuel consumption and accelerate engine wear.

Engine Belts

Alternator belts and fan belts usually have a service life of approximately 100,000–150,000 km.

Replace immediately if cracks, looseness or abnormal wear are found.

Water Pump and Fan Clutch

Under proper maintenance, water pumps and fan clutches can normally operate for approximately 800,000–1,200,000 km.

Inspection or replacement is required if there is coolant leakage, abnormal noise or unstable engine temperature.

Turbocharger

A properly maintained turbocharger can often work for around 800,000–1,200,000 km.

Inspection is recommended when problems such as increased fuel consumption, reduced power output or abnormal exhaust smoke appear.

Engine Internal Inspection

For used trucks prepared for export refurbishment, engine condition should be evaluated according to actual mileage and operating history.

For HOWO 371HP trucks, internal engine inspection is commonly considered around 800,000–1,000,000 km.

For electronically controlled engines such as R400 series trucks, cylinder liner, piston and fuel system conditions should be checked according to actual wear.

Coolant

Replace coolant approximately every 100,000 km or every 2 years.

A clean cooling system is important for trucks working in hot climates.

2. Transmission System (Clutch, Gearbox and Drive Shaft)

Clutch Assembly

The clutch disc and pressure plate normally last:

• Around 250,000–350,000 km for highway transportation

• Around 150,000–220,000 km for heavy-load mountain operation

Replacement is recommended when slipping, burning smell or difficult gear shifting occurs.

Gearbox Oil

Gearbox oil should normally be replaced every 60,000–80,000 km.

Regular oil replacement helps reduce gear wear and improves shifting performance.

Drive Shaft Universal Joints

Grease should be added approximately every 20,000 km.

Replacement is usually required around 500,000–700,000 km depending on clearance, vibration and wear condition.

Gearbox Synchronizer

Synchronizers can normally work for approximately 800,000–1,200,000 km.

Early inspection is necessary when drivers experience difficult shifting or abnormal gearbox noise.

3. Brake System

The brake system is one of the most important safety systems on heavy trucks, especially for vehicles operating under heavy loads.

Brake Linings

Typical service life:

• 80,000–120,000 km for flat highway transportation

• 40,000–60,000 km for mountainous or overloaded operations

Replace brake linings when friction material thickness approaches the safety limit (normally below 3 mm).

Brake Drums

Brake drums usually require inspection around 200,000–300,000 km.

Replace immediately if serious grooves, cracks or deformation are found.

Air Dryer

Air dryers should normally be replaced every 50,000 km or once a year.

A properly working air dryer prevents moisture accumulation inside the brake air system and reduces corrosion risks.

Brake Chambers and Air Hoses

Rubber components naturally age over time.

Brake chambers, air hoses and related pneumatic components should generally be inspected carefully after 3–5 years of operation.

Automatic Brake Adjusters

Inspect every 50,000–60,000 km.

Replace when the adjustment mechanism cannot maintain correct brake clearance.

4. Chassis, Suspension, Axles and Steering Components

Axle Gear Oil

Middle and rear axle oil should normally be replaced every 80,000 km.

For continuous heavy-load operation, the interval can be shortened to around 60,000 km.

Suspension Bushes

Leaf spring bushes and stabilizer bushes usually require attention around 100,000–150,000 km.

Replace when excessive clearance, abnormal noise or unstable handling appears.

Shock Absorbers

Shock absorbers generally last around 100,000–150,000 km.

For rough roads and mining operations, damaged shock absorbers should be replaced during refurbishment because they can accelerate tyre wear and affect vehicle stability.

Kingpin

Kingpins normally have a service life of approximately 600,000–800,000 km.

Replacement is necessary when steering play becomes excessive or the vehicle starts drifting.

Fifth Wheel (Tractor Trucks)

The fifth wheel should be inspected regularly, especially before export delivery.

A detailed inspection is recommended around every 150,000–200,000 km.

5. Tyres, Electrical System and Auxiliary Components

Tyres

Typical reference life:

• Drive axle tyres: around 80,000–120,000 km

• Steering axle tyres: around 60,000–90,000 km

Actual replacement depends mainly on tread condition, loading, road surface and operating habits.

Batteries

Maintenance-free batteries usually last around 3–4 years.

High temperature, long storage periods and poor charging conditions may shorten battery life.

Rubber Components

Water pipes, oil pipes, air hoses and sealing parts naturally deteriorate with age.

During used truck refurbishment, these components should be carefully checked and replaced if ageing, cracking or swelling is found.

Important Notes for Used Truck Export Refurbishment

Mileage is only a reference. Actual component life depends heavily on:

• Vehicle loading condition

• Driver operation habits

• Road environment

• Fuel quality

• Maintenance history

For overseas export trucks, especially vehicles delivered to Africa and other demanding markets, we recommend replacing vulnerable parts that are close to the end of their service life before shipment.

Common refurbishment inspection items include:

• Engine leakage and performance check

• Cooling system pressure test

• Brake air pressure inspection

• Gearbox and axle noise inspection

• Electrical system testing

• Tyre and suspension condition evaluation

A well-prepared used truck can significantly reduce maintenance problems after arrival and provide better long-term working performance for overseas customers.