KINGLONG bus spare parts: air conditioner 

Why choosing air conditioner for KINGLONG buses determines fleet profitability

In our practice of working with transport companies from Russia, Kazakhstan and the CIS countries, we have repeatedly encountered a situation where the purchase of a bus turned into a financial trap due to an incorrectly selected climate system. Kinglong buses (Xiamen King Long) are reliable vehicles, but their air conditioning system (ACS) is a complex unit that requires precise selection of spare parts for repair or replacement. An error in choosing a compressor or evaporator at the stage of purchasing spare parts leads not only to passenger discomfort, but to equipment downtime and losses measured in tens of thousands of rubles per month.

The key problem of the spare parts market for Kinglong buses is the huge number of modifications. The same model range, for example, XMQ6127, can be equipped with different air conditioning systems depending on the year of manufacture, the region of destination (tropics or temperate climate) and the specific order of the carrier. Using generic analogues without taking into account the technical specifications of the original equipment (OEM) often results in the system operating at its limit, the compressor overheating, and refrigerant escaping through microcracks in the connections.

This article was written by engineers who are involved in the selection and supply of VCS components for Chinese buses on a daily basis. We will not retell the advertising brochures. Here you will find a technical analysis of how to correctly identify spare parts, which parameters are critical for the Russian climate, and how to avoid buying counterfeit goods that will fail after two months of use. If you are responsible for fleet maintenance or purchasing, this information will save you budget and time.

Technical features of Kinglong air conditioning systems: what you need to know before buying

Kinglong buses use several types of air conditioning systems, and understanding these differences is the first step to choosing the right parts. Most mid- and large-class models (XMQ6900, XMQ6119, XMQ6127 series) use autonomous roof-mounted air conditioners or systems integrated into the rear of the body. However, the architecture of these systems may differ radically.

The most common configuration includes two main circuits: a high pressure (discharge) circuit and a low pressure (suction) circuit. The heart of the system is the compressor. Original Kinglong assemblies most often use compressors from the Bitzer, Valeo brands or their licensed Chinese analogues, such as Highly or Dunan. It is important to understand that even if the compressor has the same appearance and number of mounting holes, its internal performance (cooling capacity) may differ by 15-20%. Installing a less powerful compressor in a system designed for a high load will result in constant cycling (on-off), which quickly wears out the coupling and bearings.

Another critical element is the evaporator and condenser. On Russian roads, where there is a lot of dust and dirt, heat exchangers clog faster than in Europe. Original Kinglong radiators have a special anti-corrosion coating and optimized fin spacing. Cheap analogs often skimp on the quality of aluminum and copper by using thinner tube walls. This leads to freon leaks after the first season of intensive use. When choosing a spare part, always check the material of the heat exchanger: copper-aluminum binders with a protective coating are preferable.

It is also worth paying attention to the control system. Modern Kinglong buses are equipped with electronic climate control units that interact with temperature sensors in the cabin and outside. Non-original sensors may have an error of 2-3 degrees, which is why the system will not work correctly: either overcool the cabin, consuming fuel, or not cope with the heat. When replacing electronic components, it is necessary to check the compatibility of the data exchange protocol with the on-board computer of a specific bus model.

Practical advice:Before ordering spare parts, be sure to remove the nameplate from the existing compressor and write down not only the model of the bus, but also the VIN code, as well as the Part Number of the old unit. This is the only way to guarantee 100% compatibility.

Catalog of key spare parts for Kinglong air conditioners: analysis and recommendations

There are hundreds of items on the market, but the following groups of components are critical to maintaining the performance of the Kinglong bus air conditioning system. We will analyze each of them from the point of view of reliability and feasibility of replacement.

1. Air conditioning compressors

The compressor is the most expensive and complex component. Kinglong buses most often require piston or rotary compressors with a capacity of 8 to 12 kW. The main brands found in the original: Bitzer (Germany/China), Valeo (France/China), as well as Kinglong’s own developments under the KLAC brand.

• Original vs Analog:Original compressors undergo strict quality control at the Xiamen factory. Chinese analogues of the second tier (noname) can cost 40% less, but statistics show that their service life in summer heat (+35°C and above) is only 6-8 months. We recommend using either the original or certified analogues from well-known manufacturers, such as Highly, which are supplied to the conveyors of large Chinese factories.
• Important parameter:Cylinder volume and refrigerant type. Most modern Kinglong systems run on R134a freon, but older models may use R407C. A mismatch between the type of oil and freon will destroy the compressor within a few hours of operation.

2. Condensers and evaporators

These heat exchangers are responsible for transferring heat. The condenser is usually located on the roof or in the rear and is exposed to road dirt and chemicals. The evaporator is located inside the cabin and operates in high humidity conditions.

• Corrosion problem:In regions where salt reagents are used in winter, capacitors fail most often due to corrosion of the lamellas. When purchasing a new spare part, pay attention to the presence of an epoxy coating. If it is not there, it is recommended to treat the radiator yourself with an anti-corrosion compound before installation.
• Performance:The heat exchange area must strictly correspond to the original. Reducing the area (which is often done by manufacturers of cheap copies) leads to an increase in pressure in the system and the activation of emergency sensors.

3. Fan motors

Condenser and evaporator fans create air flow. Kinglong buses use DC motors (12V or 24V) with a high IP67 protection rating. Frequent breakdown is failure of bearings or windings due to overheating.

• Choice nuance:In addition to voltage and power, shaft diameter and direction of rotation are critical. An error in the direction of rotation will result in the fan heating the condenser rather than cooling it. Always check the markings on the old motor housing.

4. Control units and sensors

Electronics controls the logic of the system. Temperature, pressure and damper position sensors transmit data to the controller.

• Diagnostics:Before replacing the control unit, make sure that this is the problem. Often the cause of the malfunction is oxidation of the contacts in the connectors or damage to the wiring due to vibration load. Replacing the pressure sensor is a more frequent and cheaper procedure that solves the problem “the compressor does not turn on” in 50% of cases.

5. Maintenance components (filters, belts, couplings)

Regular maintenance includes replacing dryer filters, compressor drive belts and magnetic clutches.

• Filter drier:It must be changed every time the system is depressurized. Accumulated moisture in the filter leads to the formation of acid inside the circuit, which corrodes the insulation of the compressor windings. Saving a few dollars on this part can result in the loss of a compressor costing thousands of dollars.

Action:Make a list of frequently replaced parts for your fleet and build up a safety supply of original filters and belts. This will reduce downtime for minor repairs.

How to distinguish original Kinglong spare parts from fakes: an expert’s checklist

The bus spare parts market is full of counterfeit goods. Counterfeit brands of Bitzer, Valeo and even Kinglong itself look very similar to the original, but are made from substandard materials. In our practice, there was a case when a client purchased a batch of “original” compressors at a reduced price. After three months of operation, the valve plates of 60% of the units collapsed, which led to complete failure of the system. The investigation showed that the metal of the plates was 30% softer than the required standard.

To avoid such situations, use the following verification algorithm when accepting goods:

1. Checking packaging and labeling:Genuine Kinglong spare parts are supplied in original packaging with holographic stickers and clear printing. The barcode must be readable and match the manufacturer's database. On the unit itself, the number stamping must be deep, even and clean. Blurry characters or traces of hand engraving are a sign of a fake.
2. Visual inspection of casting and welding quality:The housings of the compressors and radiators of the original do not have burrs, weld beads or traces of rough processing. Aluminum parts must be matte, without oxidation spots. If you see oil stains on a new compressor, this is a warning sign (it may be refurbished).
3. Product weight:Counterfeits are often lighter than the originals due to the use of thinner metal or less copper in the windings. If you have the opportunity to weigh the part and compare it with the weight of the original from the catalog, a deviation of more than 5-7% should be a reason for refusal of acceptance.
4. Request for certificates:The supplier is obliged to provide certificates of conformity (GOST R or TR CU declaration) and documents from the manufacturer. The absence of a chain of documents means that the origin of the spare part is unknown.
5. Leak test (for radiators):Before installing a new condenser or evaporator, it is recommended to conduct a pneumatic test with a pressure of 1.5-2 MPa. This will reveal microcracks that may have occurred during transportation. It is better to find a defect in a warehouse than to dismantle an installed unit on the line.

Remember: Low price of Kinglong bus parts almost always means hidden risks. Savings at the procurement stage result in double costs for repeated repairs and downtime of equipment.

Specifics of operation and repair of Kinglong air conditioners in the Russian Federation and the CIS

The climatic conditions of Russia and the CIS countries impose specific requirements on bus air conditioning systems. Summer temperatures in the southern regions reach +40°C, and winter frosts in the north drop below -40°C. The system must operate reliably over this wide range.

One of the main problems is starting the system after winter downtime. The oil in the compressor thickens and the O-rings lose their elasticity. A sudden start at full power can cause the compressor to seize or rupture the high-pressure hoses. We recommend starting the system in stages in the spring: first check the static pressure, then start the fans, and only then, after 5-10 minutes, turn on the compressor at minimum speed.

Another problem is the quality of the road surface and vibration. Kinglong buses operating on intercity routes experience strong vibration loads. This leads to weakening of the mounting clamps and cracks in the solder joints of the radiators. At each maintenance (every 10-15 thousand km), it is necessary to visually inspect all connections of the air conditioning system for traces of oil (a sign of freon leakage) and tighten the fasteners. Using vibration-resistant clamps instead of standard worm clamps significantly reduces the risk of leaks.

It is also worth considering the quality of electricity in the bus’s on-board network. Voltage surges can damage the electronic air conditioner control unit. Installing a voltage stabilizer or phase control relay (for inverter-powered systems) is a sensible precaution, especially on high-mileage buses where the generator may be unstable.

Recommendation:Keep an air conditioning system maintenance log for each bus. Record the dates for refilling freon, replacing filters and repairs. This will help you identify patterns of breakdowns and plan your budget for spare parts in advance.

Logistics and spare parts procurement: how to optimize timing and cost

For transport companies, bus downtime is critical. Waiting for a spare part from China can take from 3 to 6 weeks, which is unacceptable at the height of the holiday season. Therefore, the procurement strategy must be hybrid.

First, create a stock of quickly consumable materials: filter driers, belts, fuses, relays, pressure sensors. These parts are inexpensive, but their absence can stop the system from working. It is better to purchase them in bulk from a reliable distributor with a warehouse in your country.

Secondly, for expensive components (compressors, control units, heat exchangers), use the pre-order or express delivery scheme. Work with suppliers who have direct contracts with the Kinglong plant or large component manufacturers (Bitzer, Valeo). This guarantees the availability of original parts and the ability to track the status of the order.

When importing spare parts from China, pay attention to customs clearance. Spare parts for buses often fall under different HS codes, which affects the duty rate and VAT. Correct classification of goods will help avoid fines and delays at customs. For example, compressors and radiators may have different rates. Consult a customs broker before shipping a large shipment.

We recommend asking the supplier not only for the price, but also for the warranty terms. A reliable supplier gives a guarantee of at least 6-12 months on compressors and 3-6 months on other components. Lack of warranty or a period of less than 3 months is a sign that the seller is not confident in the quality of the product.

Frequently Asked Questions

What refrigerant is used in Kinglong buses?

Most modern Kinglong bus models (manufactured after 2015) use R134a refrigerant. This is the standard for car air conditioners. However, some older models or specific modifications may use R407C or even R22 (in very old versions). Before refueling, be sure to check the sign under the hood or in the engine compartment, which indicates the type of freon and the filling rate in grams. Mixing different types of freons is unacceptable and will lead to compressor failure.

Is it possible to install a universal compressor instead of the original one?

Theoretically, yes, if the seats, pulley type and electrical connectors match. However, we categorically do not recommend doing this without careful engineering calculations. Universal compressors may have a different capacity, which will upset the balance of the system. This will either result in insufficient cooling or increased wear due to incorrect oil pressure. It is better to look for a direct analogue from a trusted brand (for example, Highly or Sanden), which has a certificate of conformity for a given bus model.

Why does the air conditioner not cool well after refueling?

There may be several reasons. The most common is the presence of air or moisture in the system. If the system has been depressurized, it must be vacuumed for at least 30-40 minutes before refueling. Vacuuming removes moisture and air. If this is not done, the water will react with the oil and freon to form an acid that will block the expansion valve or capillary tube. The second reason is a malfunction of the expansion valve or a clogged filter drier. The third is insufficient performance of the condenser fans due to contamination of the radiator.

How often should your air conditioning system be serviced?

It is recommended to carry out full maintenance of the air conditioning system twice a year: before the start of the summer season (April-May) and after its end (September-October). Maintenance includes: checking freon pressure, cleaning the condenser and evaporator, replacing the filter-drier (every 2 years or in case of depressurization), checking the belt tension and the condition of the electric coupling. Regular cleaning of radiators from dust and fluff increases cooling efficiency by 15-20% and reduces the load on the compressor.

Where can I find the wiring diagram for Kinglong air conditioner?

Wiring diagrams are usually contained in the Service Manual for the specific bus model. If you do not have a paper version, please contact an authorized Kinglong dealer or a parts supplier that specializes in this brand. Often diagrams can be found on specialized forums or in service center databases. It is important to use the diagram specifically for your year of manufacture, since the pinout of the connectors may vary.

Conclusion: An investment in the reliability of your fleet

Choosing spare parts for Kinglong bus air conditioners is not just a matter of price. It's a matter of keeping your business running smoothly. A high-quality air conditioning system increases passenger loyalty, reduces driver fatigue and increases the residual value of the bus upon sale. By using original or certified analogues, following maintenance regulations and working with trusted suppliers, you minimize the risks of unexpected costs.

We understand how important it is to get the part you need quickly and with a quality guarantee. Our companyJinan Metallid Auto LLC, specializes in supplying original and compatible spare parts for Kinglong buses, including complex air conditioning components. Located in Jinan, China's auto parts hub, we work directly with certified factory suppliers. This allows us to offer competitive prices and short delivery times, providing a full supply cycle: from precise selection of components by engineers with 15 years of experience to logistics and customs clearance.

Our approach is based on the principle of “quality first”. Each batch undergoes strict multi-level quality control, minimizing the risks of non-compliance. We offer a personalized butler-style service: transparent order support, provision of comprehensive technical data and prompt response to your requests. Don't wait for your air conditioner to fail on the hottest day of summer. Check the status of the systems right now and contact us to place an order for the necessary consumables or complex components.

Buy spare parts for KINGLONG buses: air conditioning

Contact us today