Description
Product Overview
The Hitachi HMT36FA (HMGE36EA) travel motor friction plate is a critical component of the wet multi-disc brake system in HMT36FA series hydraulic travel motors, used on Hitachi ZX200, ZX210, ZX230, and ZX240 series excavators. This friction disc provides the braking surface for the spring-applied, hydraulically released parking brake integrated into the travel drive unit.
The HMT36FA is a variable displacement swash-plate type axial piston motor designed for excavator travel applications. Combined with a planetary gear reducer, it delivers the high torque required for track propulsion in two speed ranges. The integrated wet brake system serves as a parking brake that automatically engages when travel hydraulic pressure is lost, ensuring the machine stays in position on slopes and during operation.
Common applications include Hitachi ZX200-3, ZX200-5G, ZX200LC, ZX210-3, ZX210LC, ZX230, and ZX240 series hydraulic excavators in the 20-24 ton class. Related Hitachi part numbers include brake plate 0694730 and friction plate 3064192. The motor is also cross-referenced as HMGF36FA, HMGF40FA, and HMGF40 in various parts catalogs.
Travel Motor System Specifications
| Parameter | HMT36FA / HMGE36EA |
|---|---|
| Motor Type | Swash-plate axial piston motor, variable displacement |
| Speed Modes | Two-speed (high speed / low torque and low speed / high torque) |
| Displacement Class | ~36 cm³/rev motor (combined with planetary reducer) |
| Pressure Rating | High pressure hydraulic (typical ZX200-class system pressure) |
| Brake Type | Wet multi-disc, spring-applied / hydraulically released |
| Reducer Type | Planetary gear reduction |
| Application Class | 20-24 ton excavators |
| Related Part Numbers | 9258325 (motor assy), 0694730 (brake plate), 3064192 (friction plate) |
Note: Exact displacement, pressure, and torque specifications should be verified against Hitachi official documentation for your specific motor model and machine serial number.
Wet Multi-Disc Brake System
The HMT36FA travel motor incorporates a spring-set / hydraulic-released disc type brake integrated into the travel drive assembly. This failsafe design ensures the brake is always applied when the machine is not traveling.
Brake Operation
| State | Condition | Mechanism |
|---|---|---|
| PARKED / BRAKED | No travel pressure | Brake springs press the friction disc stack together, locking the motor output shaft and preventing track rotation. This is the default failsafe state. |
| TRAVELING / RELEASED | Travel pressure applied | Hydraulic pressure builds in the brake release circuit. When pressure exceeds spring force, the brake piston retracts, separating the disc stack and allowing the motor to rotate freely. |
| STOPPING | Travel pressure decreasing | As travel flow decreases, the counterbalance valve controls deceleration. Brake release pressure drops, and springs gradually reapply the brake to hold position. |
Brake System Features
- Wet disc design: Friction plates run immersed in hydraulic oil for cooling and wear reduction
- Negative / failsafe brake: Spring-applied, hydraulically released – brakes engage if hydraulic pressure is lost
- Integrated design: Brake built into the travel motor / reducer assembly
- Counterbalance valve: Controls travel speed and prevents runaway on slopes
- Two-speed travel: Variable displacement swash plate provides high and low speed ranges
For additional technical background on excavator travel drive systems, see our final drive system guide and center joint analysis.
Axial Piston Motor Operation
The HMT36FA uses a swash-plate axial piston design to convert hydraulic energy into rotational motion for track drive.
Internal Components
| Component | Function |
|---|---|
| Cylinder Block | Houses the pistons; rotates with the drive shaft |
| Pistons | Reciprocate in cylinder bores, converting pressure to force |
| Swash Plate | Angled plate that converts piston axial motion to rotational force |
| Valve Plate | Distributes high-pressure and return oil to the correct piston bores |
| Shoe Plate / Support Plate | Transmits piston force to the swash plate surface |
| Drive Shaft | Outputs rotational torque to the planetary reducer |
| Brake Piston | Hydraulically actuated piston that releases the spring-applied brake |
| Brake Springs | Provide brake application force |
Two-Speed Operation
- Low speed (high torque): Swash plate at maximum tilt angle – maximum displacement for pushing, climbing, and heavy travel loads
- High speed (low torque): Swash plate at minimum tilt angle – reduced displacement for faster travel on level ground
The planetary gear reducer further multiplies torque and reduces speed from the motor output to the track drive sprocket, providing the high tractive effort required for excavator travel.
Excavator Travel System
Each track on the excavator is driven by its own travel motor and reducer assembly.
Complete Travel Drive System
| Component | Function |
|---|---|
| Travel Motor (HMT36FA) | Converts hydraulic energy to rotational power |
| Planetary Reducer | Reduces speed while multiplying output torque |
| Wet Brake | Provides parking and holding brake function |
| Counterbalance Valve | Controls travel speed and prevents over-speed on slopes |
| Travel Control Valve | Directs hydraulic flow to the travel motor |
| Track Chain / Sprocket | Transmits power to the track for machine movement |
Travel Functions
- Forward / reverse travel: Reversing flow direction to the motor
- Steering: Reducing speed or stopping one track while the other continues
- Two-speed shifting: Switching between high and low displacement modes
- Parking / holding: Spring-applied wet brake holds position when stopped
- Hill holding: Counterbalance valve and brake prevent roll-back on slopes
Compatible Excavator Models
Hitachi ZX Series Excavators
| Model Series | Specific Models | Tonnage Class |
|---|---|---|
| ZX200 Series | ZX200-3, ZX200LC-3, ZX200-5G, ZX200LC-5G | 20 ton class |
| ZX210 Series | ZX210-3, ZX210LC-3, ZX210-5G, ZX210LC-5G | 21 ton class |
| ZX230 Series | ZX230-3, ZX230-5G | 23 ton class |
| ZX240 Series | ZX240-3, ZX240LC-3, ZX240-5G, ZX240LC-5G | 24 ton class |
Related / Cross-Reference Motor Models
- HMGF36FA / HMGF36 – same motor family
- HMGF40FA / HMGF40 – larger displacement variant in same frame
- Part numbers: 9258325, 9243839, 9257553, 9261222, 9257254, 9233692
- Brake plate: 0694730
- Friction plate: 3064192
Note: Different model years and machine specifications may use different travel motor configurations. Always verify by checking the motor identification tag or cross-referencing with your machine serial number in the official Hitachi parts catalog.
Maintenance, Failure Modes, and Service
Common Failure Modes
| Issue | Possible Causes | Symptoms |
|---|---|---|
| Weak travel / slow speed | Worn motor components, low hydraulic pressure, swash plate mechanism issues | Reduced travel speed, lack of pushing power |
| Travel drift / pulling | Uneven motor output, brake not fully releasing, track tension mismatch | Machine pulls to one side when traveling straight |
| Brake not holding | Worn friction plates, weak brake springs, seal failure in brake piston | Machine rolls on slopes, drifts when parked |
| Brake drag | Insufficient brake release pressure, stuck piston, blocked release passage | Overheating, reduced travel speed, burning smell |
| Noise / vibration | Bearing wear, gear damage in reducer, piston shoe wear | Abnormal sounds during travel, vibration felt through tracks |
| Oil leakage | Seal degradation, damaged housing, loose connections | Oil visible around motor housing or final drive |
Maintenance Recommendations
- Hydraulic oil cleanliness: Contaminated oil is the primary cause of premature motor wear. Maintain proper filtration and change intervals.
- Check for leaks: Inspect travel motors regularly for oil seepage. Address seal issues promptly.
- Monitor travel performance: Note changes in speed, power, or tracking alignment – these indicate developing problems.
- Final drive oil: Maintain correct oil level and change intervals for the planetary reducer.
- Brake function check: Periodically verify parking brake holding power on slopes.
- Track maintenance: Proper track tension and alignment reduce side loads on the travel motor and bearings.
Our replacement parts selection and maintenance guide provides additional systematic inspection procedures for excavator components.
Friction Plate Replacement Guidelines
Inspection Checklist
| Component | Inspection Points | Replace If |
|---|---|---|
| Friction discs | Measure friction material thickness; check for cracks, glazing, delamination, scoring | Worn below minimum thickness, cracked, glazed, or delaminated |
| Steel separator plates | Check flatness, surface condition, heat discoloration | Scored, warped, or heat-damaged (blue/brown discoloration) |
| Brake piston | Inspect seals, bore condition, free movement | Leaking seals, scored bore, or sticking |
| Brake springs | Check free length, condition, tension | Fatigued, broken, or significantly weakened |
| All seals | Check O-rings and shaft seals for condition | Hardened, cracked, leaking, or damaged |
| Hydraulic oil | Check cleanliness, contamination, level | Contaminated, degraded, or low level |
Replacement Best Practices
- Replace complete set: Always replace all friction discs and steel plates together
- Replace all seals: Install new O-rings and seals during any brake service
- Thorough cleaning: Clean all internal components before reassembly
- Verify brake release: After assembly, confirm brake releases at the correct pressure
- Break-in period: New friction material requires bedding-in for optimal performance
- Follow service manual: Always use the official Hitachi service manual for exact procedures
Compatibility Verification
Before ordering HMT36FA travel motor friction plates, confirm:
- Motor model: Verify your travel motor is HMT36FA / HMGE36EA (check motor nameplate)
- Machine model: Confirm your excavator model and serial number
- Side: Left and right travel motors are often different – verify which side
- Part numbers: Cross-reference with existing part numbers from your parts catalog
- Quantity: Note the number of friction and steel plates per motor
- Brake type: Confirm wet multi-disc spring-applied brake (standard on ZX series)
If uncertain about fitment, send us your motor model number, machine model, and serial number and we will help verify compatibility.
Ordering and Supply Information
| Parameter | Detail |
|---|---|
| Product | Wet brake friction plate for Hitachi HMT36FA / HMGE36EA travel motor |
| Motor Compatibility | Hitachi HMT36FA, HMGE36EA, HMGF36FA series travel motors |
| Machine Applications | Hitachi ZX200, ZX210, ZX230, ZX240 series excavators (20-24 ton class) |
| Brake Type | Wet multi-disc parking brake (spring-applied, hydraulically released) |
| Related Part Numbers | 0694730 (brake plate), 3064192 (friction plate), 9258325 (motor assy) |
| Origin | Made in China |
| Warranty | 6 months |
| Minimum Order | 1 piece |
| Unit Price | Negotiable (contact for quotation) |
| Bulk Pricing | Available for orders of 50+ pieces |
| Lead Time | 1-5 business days |
| Monthly Capacity | 1,000 pieces |
| Packaging | Neutral export packaging / wooden cases |
| Payment Methods | T/T, PayPal, Western Union |
We supply a full range of travel motor components including friction discs, steel separator plates, brake pistons, springs, cylinder blocks, valve plates, piston sets, and seal kits for HMT and HMGF series motors.
We ship worldwide from China with multiple logistics options: express courier (5-10 days to Southeast Asia), air freight (7-14 days), and sea freight (15-30 days). Both single-piece sample orders and bulk orders for parts dealerships, repair shops, and fleet operators are accepted.
Browse our complete construction equipment parts catalog or read our guide to evaluating reliable parts suppliers before purchasing.
