Truck KrAZ-5233 with full weight 28 tons and lifting capacity 13 tons often encounters problems with the engine cooling system YaMZ-238 — overheating due to a clogged radiator or a malfunctioning thermostat. If the coolant temperature exceeds 95°C When driving under load, first check the tightness of the pipes and the level of antifreeze in the expansion tank. This model, produced by the Kremenchug Automobile Plant in 1990s, requires special attention to fuel equipment and gearbox YaMZ-236P, where the wear of the synchronizers is manifested by a crunching sound when switching to 3rd and 4th gears.
Structurally KrAZ-5233 belongs to the family of three-axle trucks with a wheel arrangement 6×4equipped with a diesel engine 14.86 l and power 240 hp. Its chassis is used for mounting dump bodies, tanks and special equipment, but the rear axle remains the weak point KrAZ-256B1 — play in the hub bearings appears here after 150,000 km mileage Owners also note increased fuel consumption (up to 32 l/100 km) when operating with a trailer, which is associated with non-optimal settings of the high pressure fuel pump (HPF).
Technical characteristics of KrAZ-5233
Basic equipment KrAZ-5233 designed to work in difficult road conditions, including off-road and construction sites. The truck is equipped with a manual 5-speed gearbox with a divider, which allows you to choose 10 speeds forward and 2 ago. Maximum speed limited 80 km/h, however, when fully loaded, the actual speed rarely exceeds 60–65 km/h due to insufficient engine power.
Key chassis parameters:
- 🔧 Engine: YaMZ-238M2 (V8, 14.86 l, 240 hp at 2100 rpm)
- 🛢️ Fuel tank: 2 × 125 l (total volume 250 l)
- 🔄 Gearbox:
YaMZ-236P(5+1 with divider) - 🚛 Load capacity: 13,000 kg (permissible trailer weight - 12,000 kg)
- 📏 Dimensions: 8900×2500×2950 mm (length/width/height)
| Parameter | Meaning |
|---|---|
| Wheel formula | 6×4 |
| Curb weight | 15,000 kg |
| Maximum lift | 30% (17°) |
| Brake system | Pneumatic, dual-circuit |
| Tire size | 12.00-20 (300-508) |
⚠️ Attention: During operation KrAZ-5233 With a trailer, it is mandatory to check the pressure in the pneumatic brake system. Pressure drop below 6.5 kg/cm² leads to failure of the rear bogie brakes.
Typical faults and their causes
Most common breakdowns KrAZ-5233 associated with wear of transmission and engine components. For example, knocking noise in the front axle at speeds above 40 km/h usually indicates play in the ball joints or wear in the wheel bearings. In the engine YaMZ-238 after 200,000 km mileage often requires replacement of crankshaft liners and repair of cylinder heads due to cracks between the valve seats.
Other common problems:
- 🔥 Engine overheating: clogged radiator, faulty water pump or thermostat.
- ⚡ Electrical problems: oxidation of contacts in the fuse box, failure of the generator
G287. - 🛑 Poor braking: air leak in the pneumatic system, wear of brake pads or drums.
- 🔧 Oil leak: wear of the crankshaft or rear axle seals, cracks in the oil pan.
Requires special attention hydraulic body tipping system (if the car is a dump truck). Leakage of working fluid from cylinders or pumps NSh-32 leads to slow lifting of the body or complete failure of the mechanism. Signs of malfunction: noise during pump operation, jerking when lifting, lower pressure drop in the system 100 kg/cm².
Diagnostics of the YaMZ-238 engine
Engine YaMZ-238 on KrAZ-5233 sensitive to the quality of fuel and oil. The first signs of trouble are black smoke from the exhaust pipe (overrich mixture) or white smoke (coolant entering the cylinders). For diagnostics, check:
- Compression in the cylinders (normal - 28–32 kg/cm²).
- Condition of the injectors (injection pressure should be 220–230 kg/cm²).
- Valve clearances (intake - 0.25–0.30 mm, graduations - 0.35–0.40 mm).
Check the oil and antifreeze levels|Inspect the pipes for cracks|Bleed the fuel system|Listen to the engine for extraneous noise-->
If the engine stalls at idle, the reason could be:
- 🔧 Clogged fuel filter or pipelines.
- ⚡ Malfunction of the fuel injection pump speed regulator.
- 🔥 Air leaks into the fuel system through cracks in the hoses.
⚠️ Attention: When changing engine oil YaMZ-238 use only grade oils CF-4/CH-4 with viscosity 15W-40. Filling with low quality oil leads to scuffing on the bearings and crankshaft within 50,000 km.
Repair of YaMZ-236P gearbox
Gearbox YaMZ-236P on KrAZ-5233 requires adjustment every 80,000–100,000 km. Main symptoms of malfunctions:
- 🔧 Difficulty shifting gears: wear of synchronizers or shaft bearings.
- 💥 Crunch when switching: failure of gear teeth or synchronizer couplings.
- 🔊 Extraneous noise: play in the bearings of the primary or secondary shaft.
To replace synchronizers you will need:
- Drain the oil from the box (volume - 12 l).
- Remove the gearbox cover and remove the output shaft.
- Replace worn rings and synchronizer couplings (catalog numbers: 236-1702010 for 2nd gear, 236-1702020 for the 3rd).
- Check the clearances between the gears and shafts (tolerance - 0.1–0.3 mm).
How to check gearbox shaft play without disassembly
Jack up the rear of the car and put the gear in neutral. Rock the driveshaft with your hands and evaluate the play: if it exceeds 1–2 mm, the bearings need to be replaced.
| Malfunction | Reason | Remedy |
|---|---|---|
| Oil leak from gearbox | Worn seals or crack in the crankcase | Replacing oil seals (article no. 236-1701030), crankcase sealing |
| Spontaneous gear shutdown | Worn forks or retainer balls | Replacement of clamps (set 236-1702060) |
| Noise when coasting | Play in the intermediate shaft bearings | Replacing bearings (part number 236-1701120) |
Brake system maintenance
Pneumatic braking system KrAZ-5233 requires monthly check:
- 🔧 System pressure: there must be 7–8 kg/cm² with the engine running.
- 🛠️ Brake pad condition: minimum thickness of friction material - 5 mm.
- 🔄 Compressor operation: productivity - no less 220 l/min at 2000 rpm.
If the brakes grasp unevenly, check:
- Pressure balance in the circuits (the difference should not exceed 0.5 kg/cm²).
- Condition of the brake chambers (cracks or air leaks).
- Adjusting the gap between the pads and drums (the norm is 0.2–0.4 mm).
To extend the life of your brake pads, avoid prolonged braking on downhill grades. Use the retarder (if equipped) or lower gears.
⚠️ Attention: When replacing brake hoses, use only reinforced products with working pressure not less than 10 kg/cm². Standard rubber hoses burst under stress, resulting in complete brake failure.
Electrical equipment: diagrams and repairs
Electrical diagram KrAZ-5233 built on single wire system with a negative pole to ground. Frequent problems:
- ⚡ Battery does not charge: generator is faulty
G287or relay regulatorPP362. - 💡 Headlights do not light up: oxidation of contacts in the fuse box or broken wiring.
- 🔋 Weak starting current: sulfation of battery plates or wear of starter brushes
ST230-A1.
To check the generator:
- Start the engine and turn on the high beams.
- Measure the voltage at the battery terminals: normal - 27–29 V.
- If the voltage is lower 26 V, check the diode bridge or field winding.
When replacing fuses in the block PR115 use only original inserts on 20A (for lighting circuits) and 30A (for starter circuits). Installing "bugs" leads to a fire in the wiring.
Modernization and tuning of KrAZ-5233
Owners KrAZ-5233 The truck is often upgraded to improve reliability:
- 🔧 Turbocharging installation: allows you to increase engine power up to 300 hp (set
YaMZ-238T). - 🛢️ Replacing the fuel tank: increase in volume to 300 l for long haul flights.
- 🔄 Suspension reinforcement: installation of additional springs or air cylinders.
- 💡 LED lighting: replacing standard headlights with LED spotlights (for example,
Hella Rallye 4000).
When tuning the engine it is recommended:
- Install an intercooler to reduce the charge air temperature.
- Replace the standard air filter with a zero-resistance filter (for example,
K&N 33-2075). - Adjust the fuel injection pump on the stand to optimize fuel supply.
How to check turbine efficiency
After installing the turbocharger, start the engine and press the gas hard. If the turbine is working properly, you will hear a characteristic whistle and feel an increase in thrust after 1500 rpm.
FAQ: Frequently asked questions about KrAZ-5233
What is the service life of the YaMZ-238 engine on the KrAZ-5233?
If you follow the maintenance schedule (oil change every 10,000 km, fuel filters - every 20,000 km) the engine passes 400,000–500,000 km before major repairs. However, in difficult conditions (construction sites, off-road conditions), the resource is reduced to 300,000 km.
What kind of oil should I put in the gearbox?
For gearbox YaMZ-236P gear oil recommended TAD-17I or TM-5-18 (viscosity grade 85W-90). Refill volume - 12 l. Replacement required every 50,000 km or once every 2 years.
Why does the KrAZ-5233 pull poorly on an incline?
The reasons may be as follows:
- Clutch wear (disc slipping).
- Insufficient engine power (clogged fuel system or worn fuel injection pump).
- Incorrect operation of the divider in the gearbox (downshift does not engage).
- Problems with the rear axle (play in the final drive).
For diagnostics, check the boost pressure (should be 0.8–1.0 kg/cm² at 2000 rpm) and clutch condition.
How to adjust the clutch?
The adjustment is carried out in two stages:
- Set the gap between the release bearing and the basket arms (3–4 mm).
- Adjust the free play of the clutch pedal (25–35 mm).
After adjustment, check for smooth gear shifting. If the clutch "leads", increase the gap by 1 mm.
Is it possible to install gas equipment on the KrAZ-5233?
Installation of HBO is technically possible 4th generation (for example, Lovato Smart or BRC Sequent), but requires:
- Modification of the power system (installation of a gas reducer and injectors).
- Reconfiguring the ECU (if installed) or mechanical adjustment of the fuel injection pump.
- Strengthening the suspension (gas cylinders increase the weight by 100–150 kg).
The payback for such modernization is 1.5–2 years when running from 100,000 km/year.