Maintenance and repair tips for bulldozers, Collector's Edition.

I. Overview

Technical maintenance is a very important task. If done well, it can not only ensure the safe operation of the bulldozer but also extend its service life. Therefore, before and after the operation, the bulldozer should be inspected and maintained as required. During the operation, it is also necessary to constantly pay attention to whether there are any abnormal situations occurring during the operation of the bulldozer, such as abnormal noises, odors, vibrations, etc., so as to detect and solve problems in a timely manner and avoid serious consequences due to the deterioration of minor faults. At the same time, if technical maintenance is done well, it can also extend the major and medium repair cycles of bulldozers and fully exert their efficiency.

Ii. Fuel System

1. The fuel used for diesel engines must be selected in accordance with the relevant provisions of the "Fuel Use Regulations" and in combination with the local working environment, suitable diesel. The specifications and performance of diesel should comply with the provisions of GB252-81 "Light Diesel".

2. The oil storage vessels should be kept clean.

3. The new oil should undergo a considerable period of sedimentation treatment (preferably seven days and nights), and then be slowly sucked out and filled into the diesel tank.

4. It is best to fill the diesel tank of the bulldozer with diesel immediately after the operation is completed to prevent the gas in the tank from condensing and mixing into the oil. At the same time, the oil used the next day should be given a certain period of time to allow water and impurities to settle in the tank for easy removal.

5. When refueling, keep the operator's hands clean of the oil drum, diesel tank, refueling port, tools, etc. When using an oil pump, be careful not to draw up the sediment at the bottom of the bucket.

6. When refueling. No fire is allowed nearby.

7. The oil level should be checked frequently. When it is less than the lower limit mark on the dipstick, it must be replenished.

The filter screen at the fuel filler port should be cleaned once every 100 hours.

9. Each diesel filter should have its sediment removed in a timely manner according to the working environment, but the maximum interval should not exceed 200 hours. After removing the sediment, venting should be carried out to avoid problems such as difficult starting and insufficient power.

Iii. Cooling System

1. Use of cooling water:

Distilled water, tap water, rainwater or clean river water should be used as the cooling water for diesel engines. It is strictly prohibited to use dirty water or hard water (well water, mineral water and other water with high salt content) to avoid scaling and corrosion of the cylinder liner. Only under hard water conditions must it be softened and replenished before it can be used.

(2) When adding water to the radiator, it may not be possible to fully fill the cooling system at one time. After the diesel engine starts running, it should be checked again. If it is insufficient, it should be filled up. The water inlet of the cooling system is located at the top of the small top cover of the bulldozer.

(3) Under continuous operation, the cooling water should be replaced every 300 hours or so. There are five drain valves for the cooling system of the bulldozer diesel engine: 1 is located at the bottom of the radiator; 2 is located at the lower part of the water-cooled oil cooler of the diesel engine. 3 is located at the front end of the diesel engine, at the circulating water pump. 4 is located at the left front of the transfer case, on the diesel engine block. 5 is located at the lower end of the water tank outlet pipe.

2. Scale treatment

Scale treatment should be carried out on the diesel engine cooling system every 600 hours.

When dealing with scale, it is generally advisable to first clean it with an acidic cleaning solution and then neutralize it with an alkaline water solution. Through chemical reactions, insoluble scale is transformed into water-soluble salts and discharged with water.

The specific operation process is as follows:

(1) Remove the thermostat of the cooling system.

(2) Start the diesel engine and raise the water temperature to 70 to 85 degrees Celsius. Once the floating scale floats up, immediately turn off the engine and drain the water.

(3) Pour the prepared acidic cleaning solution into the water tank, start the diesel engine, and run it at 600 to 800r/min for about 40 minutes. Then turn off the engine and drain the cleaning solution.

Preparation of acidic cleaning solution

Add three kinds of acids to clear water in the following proportions:

Hydrochloric acid: 5-15%

Hydrofluoric acid: 2-4%

Hydroxyacetic acid: 1-4%

After stirring evenly, it can be used.

In addition, an appropriate amount of polyoxyethylene alkyl allyl ether can be added as needed to enhance the permeability and dispersion of scale. The operating temperature of acidic cleaning solution should not exceed 65°C. The preparation and use of the cleaning solution can also be carried out in accordance with the relevant contents in the "135" series diesel engine operation and maintenance manual.

(4) Then inject a 5% sodium carbonate aqueous solution to neutralize the acidic cleaning solution remaining in the cooling system. Start the diesel engine and let it run slowly for 4 to 5 minutes, then turn it off and release the sodium carbonate water solution.

(5) Finally, inject clean water, start the diesel engine and make it run at varying speeds. Use the clean water to flush out the residual solution in the cooling system. After circulating for a while, turn off the engine and drain the water. Follow this process and repeat the operation several times until the water released is neutral when tested with litmus paper.

Within 5 to 7 days after cleaning, the cooling water should be replaced every day to prevent residual scale from blocking the drain valve.

3. Use of antifreeze:

Antifreeze can be used in extremely cold and low-temperature conditions.

Iv. Air Filter

If the air filter is carefully maintained technically in accordance with the usage regulations, not only can its service life be prolonged, but it can also provide a good working condition for the diesel engine. Therefore, the following points should be noted when using it:

1. Every 100 to 200 hours of engine operation, the paper filter element should be removed and cleaned by vibrating or blowing compressed air (with a pressure not exceeding 0.49 MPa) from the center of the filter element outward or gently tapping its end surface. It is strictly forbidden to clean it with any oil or water.

The paper filter element should be replaced with a new one every 1,000 to 2,000 hours of operation.

The internal safety filter element should be replaced every 3,000 to 4,000 hours of operation.

4. When installing the paper filter element, it must be reliably sealed without air leakage or short circuit.

5. If the paper filter element is clogged with oil, water or other contaminants, causing the engine exhaust to be too thick, and the situation still cannot be improved after cleaning the filter element or if the paper element is damaged, a new filter element should be replaced.

6. The connecting pipelines between the air filter outlet and the diesel engine intake pipe, as well as the connection points between the air filter dust collection chamber and the exhaust ejector rubber hose, should be sealed reliably without any air leakage.

7. When the diesel engine is in operation, it is strictly prohibited to remove the air filter.

V. Electrical System

The technical maintenance of various components in the electrical system, especially the battery, has a significant impact on their service life. Therefore, it is necessary to do it carefully in accordance with the regulations.

1. Battery

There are two 6-OA-195 dry-charged batteries in the electrical system of this machine, which are used in series. The system voltage is 24V. The rated voltage of each battery is 12V, and its 20-hour rate discharge capacity is 195 ·h.

(2) First filling and use

The electro-hydraulic system must be composed of chemically pure sulfuric acid and distilled water. The liquid temperature during use should not be lower than 21℃ (for 70T) or equal to 32℃ (for 90F).

B. The specific gravity of the electro-hydraulic system depends on the climate and temperature of the region where it is used. The room temperature is:

The electro-hydraulic specific gravity at 30 ° C to 40 ° C is 1.270.

The specific gravity of the electro-liquid at 20℃ to 30℃ is 1.280.

The specific gravity of the electro-liquid at temperatures below 20°C is 1.290.

C. After the battery is installed, the liquid level should be checked immediately. If the electrolyte is less than 10mm higher than the protection board, an appropriate amount of electrolyte must be added.

Before installing the battery, if there is sufficient time, charging it for 3 to 4 hours will be more beneficial to the battery's performance.

E. After the electro-liquid is filled, it must be charged at a 10-ampere charging rate for 3 to 4 hours within 12 / J ', or during use when the usage time is short, or when the generator malfunctions.

F. The effective dry charge time of this battery is 12 months. When in use, if the battery's effective 1000-charge period has exceeded, it can be charged at the above charging rate. The charging time should continue until a large number of bubbles emerge from the electrolyte, and the voltage and specific gravity of the electrolyte remain stable continuously for 5 hours.

(3) Battery maintenance

A. The electro-hydraulic level should be 10mm higher than the protective plate. During the usage period, if the level is insufficient, only distilled water can be used to replenish it.

B. Regularly tighten the liquid injection port plug and keep the battery and its surrounding area dry and clean.

C. If the battery is used without charging, when the specific gravity of the electro-liquid drops to 1.175, it must be stopped from use and charged. The charging time should be until the specific gravity of the electro-liquid returns to the specified reading and remains stable for three hours.

D. Batteries that are idle and not in use should be charged once a month.

E. The end posts and wire clamps can be coated with a thin layer of Vaseline to prevent corrosion.

2. Starting motor

(1) Regularly check whether the fasteners of the starter motor are firmly connected, whether the wire contact is tight, and remove accumulated dirt.

(2) Regularly inspect and keep the commutator clean, the brushes not stuck, and the pressure of the top spring normal. If the brushes are worn and the commutator surface is scorched, they should be repaired and replaced immediately.

(3) Check whether the insulation of the wires is damaged.

3. Charging generator: The charging generator should be disassembled and maintained once every 1,000 to 1,500 hours of operation. The contents are as follows:

(1) Use compressed air or a blower to blow off the dust on all parts, and wipe off the oil stains on the collector rings and coils with gasoline.

(2) Clean the bearings and replace the grease. The front and rear end covers of the charging generator are equipped with rolling bearings, which are lubricated with compound calcium-based grease. The filling amount should not be too much, especially if too much is added to the rear cover bearings, it is easy for the grease to overflow and splash onto the slip rings, causing poor contact and affecting the performance of the charging generator.

(3) Check whether there is any desoldering phenomenon in the coil, rotor and rectifier components. Check if there is any open circuit or short circuit in the drying coil. If there is any desoldering, it should be repaired; if there is any burning damage, it should be replaced.

(4) When inspecting rectifier components, a multimeter must be used. It is strictly forbidden to use a megohmmeter (megohmmeter) or a power supply higher than 30V for detection. First, connect the "ten" probe to the "Ten" lead-out terminal of the generator, and then connect the "one" probe to the "one" lead-out terminal of the generator. The multimeter reading should be around 40Q. For example, connect the "one" probe to the "Ten" lead-out terminal of the generator, and connect the "+" probe to the "one" lead-out terminal of the generator. Then the multimeter reading should be above 10000Q, indicating that the rectifier component group is normal. Otherwise, it is an abnormal measurement. The generator wiring group and the connection wires of the components should be disconnected, and the rectifier components should be measured one by one with a multimeter.

(5) Check the wear condition of the brushes and whether the pressure of the brush spring is normal, as well as whether the insulation of the brush holder and the lead screw to the ground is good. If the brushes are worn too much, they should be replaced.

4. Charging generator regulator

(1) The regulator of the charging generator is a relatively precise electrical appliance. Do not adjust it at will. When it is confirmed that the regulator has malfunctioned, first check the location of the fault. Generally speaking, the first step should be to check whether the contacts are contaminated or not. The regulator spring only serves to increase or decrease the voltage data. When the spring is stretched, the data rises; conversely, it drops.

(2) The charger generator regulator should have its data checked and contacts repaired on a dedicated device every 350 working hours. The operating voltage of the FT221 relay is 8 to 10 volts. When the voltage regulator is half-loaded, the regulated voltage is 27 to 29 volts.

(3) When the relay contacts are separated, the gap between the armature and the core is 0.8 to 1 mm, and the gap between the contacts is 0.8 to 1 mm. The gap between the armature and the core of the voltage regulator is 1.4 to 1. "smm.

5. Other components

Other components can be technically maintained in accordance with the instructions of each manufacturer.

Vi. Hydraulic System

A bulldozer has three hydraulic systems, namely the main clutch hydraulic system, the steering hydraulic system and the working device hydraulic system. The oil used in the hydraulic system should be kept clean and in sufficient quantity frequently. This is one of the important conditions for extending the service life of the hydraulic system. Therefore, the oil level should be checked every 60 hours. There are three places to check the oil level. The first one is the oil filling port of the main clutch hydraulic system, located at the upper part of the main clutch. 2 is the fuel filler port of the steering hydraulic system, located above the rear axle box and to the right of the driver's seat. 3 is the oil filling port of the hydraulic system of the working device, located on the upper side of the hydraulic control box. There is a dipstick of 4 at all three refueling points within the day. It can be used to check the height of the oil level.

When the oil level is found to be insufficient, replenish the used oil in time.

2. When oil leakage is detected, the cause should be identified promptly to eliminate it.

3. If the oil is found to have deteriorated or become dirty, it should be replaced with new oil in time or drained, filtered and reused.

Under normal circumstances, change the oil every 800 to 1,200 hours of use (for new machines, change the oil every 60 hours of initial use). When changing the oil, the filter screens of the oil filters in each hydraulic system must be thoroughly cleaned. Paper filter elements can only be cleaned by shaking in light diesel oil or kerosene. It is strictly forbidden to scrub them with a brush. Magnetic oil filters should also be cleaned thoroughly. When changing the oil in each hydraulic system, the dirty oil should be drained as much as possible, and the system should be thoroughly cleaned. Then, new oil should be added in accordance with the oil usage regulations.

The main clutch hydraulic system and the steering hydraulic system can be drained of oil and cleaned as usual. When the hydraulic system of the working device is discharging oil, operate the bulldozer control lever to lift the scraper to the highest position, then turn off the diesel engine, open the magnetic oil plug at the bottom of the hydraulic control box to discharge the oil, and finally move the bulldozer control lever to make the scraper slowly touch the ground, thereby discharging the remaining oil in the cylinder. Wash after draining the oil completely. If the bulldozer is equipped with a soil loosening device, the oil discharge process of the hydraulic oil in the soil loosening cylinder is similar to that of the oil cylinder of the aforementioned bulldozer device.

Add oil with the special funnel provided randomly. After adding oil, run the diesel engine at a low speed. Lift and lower the scraper 3 to 5 times repeatedly, and then add oil to the oil tanks of each hydraulic system until the liquid level reaches the required level.

Vii. Regular maintenance

1. 8-10 hour technical maintenance

Before work:

A. In accordance with the relevant provisions of this manual, add oil or grease to each oil tank and lubrication point on time and in the prescribed quantity.

B. Fill up the cooling water.

C. Check if the nuts and other components are loose or missing. If so, they should be tightened and replenished.

D. Check whether each control lever is flexible and reliable, and whether the travel is normal.

E. Check whether the exhaust and sound of the diesel engine are normal and if there is any leakage.

F. Check whether all kinds of instruments are working properly and eliminate any abnormal phenomena in time.

G. If there is any oil leakage or abnormal noise from any component, it should be eliminated in time.

H. Remove the dust from the dust collection cup of the air filter.

(2) After work:

A. Clean all components and check for any loss, damage or leakage.

B. Fill the diesel tank to the brim with diesel.

C. In summer, fill with cooling water. In winter or in cold regions, drain the cooling water completely or add antifreeze.

"d Store properly.

2. 60-hour technical maintenance

(1) Follow all the provisions of the 8-10 hour technical maintenance.

(2) Adjust the tightness of the fan belt.

(3) Check the liquid level height and density of the battery electrolyte. If it is insufficient, replenish or charge it.

(4) Check whether there are any short circuits, open circuits or damages in the electrical system.

(5) Check the operation of the transmission system and the oil level. If there is a fault, it should be eliminated. If the oil is insufficient, it should be replenished.

(6) Check the tension of the tracks and make adjustments if necessary.

(7) Remove the dirt from the diesel engine oil pan and check the oil level.

(8) Check the oil levels in each hydraulic system and add oil. When a new machine is first used, the oil should be changed.

3. 125 to 150 hours of technical maintenance

(1) Follow all the provisions of the 60-hour technical maintenance.

(2) Clean the filter elements of each oil filter.

(3) Replace all the cooling water.

(4) Adjust the fan belt.

(5) Clean the air filter element or replace it.

(6) Check the oil levels of all components in the transmission system and add oil if necessary.

(7) Check the oil level in the hydraulic control box and add oil if necessary.

4. 300-hour technical maintenance

The technical maintenance shall be carried out in accordance with the provisions of each article for 125 to 150 hours.

(2) Clean each cooling system.

(3) Adjust the travel of each joystick.

(4) Tighten the bolts and nuts of the track plates.

(5) Check the lubricating oil of the guide wheel and the idler wheel, and inspect the working condition of the floating oil seal.

(6) Filter or replace the oil used in each lubrication system of the diesel engine.

5. Disassembly, assembly and maintenance

This machine must be disassembled and maintained after working for 4,000 to 6,000 hours. After disassembly and maintenance, it is required