Description
Product Overview
The T228727, AT339059, and AT339543 service brake components are critical parts of the wet multi-disc brake system on John Deere 310 series backhoe loaders and related models. These components provide service braking for the machine through hydraulically actuated, oil-immersed brake discs that deliver reliable stopping power with long service life and minimal maintenance.
T228727 is the steel brake disc plate (4-tang drive plate) that provides the mating surface for friction material. AT339059 is the right-hand service brake friction disk, and AT339543 is the left-hand service brake friction disk set. Together with additional steel and friction plates, they form the inboard wet multi-disc brake assembly that operates immersed in hydraulic oil for superior heat dissipation and wear resistance.
The brake system is foot-operated, fully hydraulic, and can be applied individually or simultaneously. The self-adjusting and self-equalizing design ensures consistent brake performance as the friction material wears. This braking system meets industry standards for construction equipment braking performance and safety.
Technical Specifications
T228727 – Steel Brake Disc Plate
| Parameter | Specification |
|---|---|
| Part Number | T228727 |
| Component Type | Steel brake disc plate / separator plate |
| Outer Diameter | 235.08 mm (9.255 inches) |
| Inner Diameter | 153.92 mm (6.060 inches) |
| Thickness | 4.04 mm (0.159 inches) |
| Drive Tangs | 4 tangs (external drive tabs) |
| Tang Width | 44.96 mm (1.770 inches) |
| Material | High-quality steel |
| Surface Finish | Machined flat, corrosion-resistant |
AT339543 – Left-Hand Service Brake Friction Disk Set
| Parameter | Specification |
|---|---|
| Part Number | AT339543 |
| Component Type | Service brake friction disk set, left-hand |
| Weight | 0.89 kg (1.96 lb) |
| Outer Diameter | Approx. 233.68 mm (9.2 inches) |
| Thickness | Approx. 5.59 mm (0.22 inches) |
| Friction Material | High-friction composite material on steel core |
AT339059 – Right-Hand Service Brake Friction Disk
| Parameter | Specification |
|---|---|
| Part Number | AT339059 |
| Component Type | Service brake friction disk, right-hand |
| Function | Friction element for right-side service brake |
| Material | High-friction composite on steel backing |
| Orientation | Right-hand specific (mirror of AT339543) |
All components are designed for wet brake operation where the discs are continuously bathed in hydraulic oil. The oil cools the friction surfaces, carries away wear particles, and prevents corrosion – dramatically extending service life compared to dry brake systems.
Wet Multi-Disc Brake System
John Deere 310 series backhoe loaders use a fully hydraulic, foot-operated, inboard wet multi-disc brake system. This design is a significant upgrade over dry brake systems, especially for machines working in dusty, muddy, or harsh construction environments.
System Features
| Feature | Description | Benefit |
|---|---|---|
| Wet disc design | Brake components run immersed in hydraulic oil | Excellent cooling, corrosion protection, long life |
| Inboard mounting | Brakes mounted inside the axle housing | Protected from dirt, rocks, and debris |
| Hydraulic actuation | Foot pedal operates hydraulic piston | Smooth, consistent braking force |
| Self-adjusting | Automatic adjustment as friction material wears | Consistent pedal feel, no manual adjustment needed |
| Self-equalizing | Balanced pressure across disc stack | Even wear, consistent braking left/right |
| Individual or simultaneous | Brakes can be applied independently or together | Versatile for different operating conditions |
How the Brakes Work
- Brake application: When the operator presses the brake pedal, hydraulic pressure is directed to the brake piston in the axle housing.
- Disc compression: The piston compresses the alternating stack of steel brake discs (T228727) and friction discs (AT339059 / AT339543) together.
- Friction generation: The friction material on the discs binds against the steel surfaces, creating drag that slows and stops the axle.
- Heat dissipation: Heat generated during braking is absorbed by the surrounding hydraulic oil, which circulates through the system to prevent overheating.
- Brake release: When pedal pressure is released, hydraulic pressure drops and the piston retracts. The disc stack separates, allowing the axle to rotate freely with minimal drag.
Important: These are service brake components, not transmission clutch parts. John Deere PowerShift transmissions in 310 series backhoes use separate clutch disc assemblies with different part numbers (such as AT339922 / T229406 clutch disc kits). Do not confuse brake discs with transmission clutch discs.
For additional technical background on heavy equipment hydraulic and drivetrain systems, see our final drive system guide and center joint analysis.
Compatible Backhoe Loader Models
T228727 Compatible Models
| Series | Models |
|---|---|
| 210 Series | 210K EP, 210K, 210L EP, 210L, 210LJ |
| 310 J/K/L Series | 310J, 310K EP, 310K, 310L EP, 310L |
| 310 SJ/SK/SL Series | 310SJ, 310SK, 310SK TC, 310SL |
| 315 Series | 315SJ, 315SK, 315SL |
| 325 Series | 325J, 325K, 325SK, 325SL |
| 410 Series | 410J, 410J TMC, 410K, 410K TC, 410L |
AT339543 (Left) Compatible Models
| Series | Models |
|---|---|
| 210 Series | 210K, 210K EP, 210L, 210L EP, 210LE, 210LJ |
| 310 J/K/L Series | 310J, 310K, 310K EP, 310L, 310L EP |
| 310 SJ/SK/SL/TJ/TK Series | 310SJ, 310SK, 310SL, 310SL HL, 310TJ, 310TK TMC |
| 315 Series | 315J, 315SK, 315SL |
| 325 Series | 325J, 325SK, 325SL |
| 410 Series | 410J, 410K, 410L, 410TK TMC |
AT339059 (right-hand) is compatible with the same model range as AT339543 (left-hand). Always replace left and right brake components together for balanced braking performance.
Maintenance and Service
Recommended Maintenance Schedule
| Interval | Service Action | Purpose |
|---|---|---|
| Daily / Pre-shift | Check brake pedal feel and travel | Detect changes in brake performance early |
| Every 500 hours | Inspect brake system for leaks; check hydraulic oil level | Identify hydraulic issues before they affect braking |
| Every 1,000 hours / 24 months | Flush and replace brake hydraulic fluid; inspect shock absorbers and struts | Maintain fluid quality and system integrity |
| As needed | Inspect brake discs and friction plates | When braking performance decreases or oil shows contamination |
Brake Inspection Checklist
| Component | Inspection Point | Replace If |
|---|---|---|
| Steel discs (T228727) | Thickness, flatness, surface scoring, heat discoloration, tang wear | Worn below limit, warped, scored, heat-damaged, or tangs worn |
| Right friction disk (AT339059) | Friction material thickness, surface condition, even wear | Worn below minimum, cracked, delaminated, or contaminated |
| Left friction disk (AT339543) | Friction material thickness, surface condition, even wear | Worn below minimum, cracked, delaminated, or contaminated |
| Left-Right Balance | Compare wear on both sides | Significant difference indicates misalignment or hydraulic issue |
| Hydraulic System | Fluid level, condition, leaks at lines and cylinders | Leaks found, fluid contaminated, or low level |
| Brake Piston / Seals | Seal condition, piston free movement | Leaking seals, sticking piston |
Brake System Bleeding
After any brake service that involves opening the hydraulic system, proper bleeding is essential:
- Ensure hydraulic reservoir is at correct level
- Follow the service manual bleeding procedure (typically starting from the furthest brake)
- Pump brake pedal and open bleed valve to release air
- Repeat until no air bubbles appear in the fluid
- Top up reservoir after bleeding is complete
- Test brake pedal feel and braking performance before returning machine to service
Our replacement parts selection and maintenance guide provides additional systematic inspection procedures for construction equipment.
Replacement Guidelines
When servicing the wet disc brake system on John Deere backhoe loaders, follow these best practices:
- Replace in pairs: Always service both left and right brakes at the same time for balanced braking.
- Complete inspection: Inspect all components in the brake stack, not just the obviously worn parts.
- Steel and friction together: When replacing friction discs, inspect steel discs carefully. Replace any that are scored, warped, or heat-damaged.
- Seal replacement: Always replace piston seals and O-rings during brake service to prevent leaks.
- Fluid change: Drain and replace hydraulic fluid when performing major brake service.
- Burnish-in: New friction material requires a break-in period. Avoid heavy braking for the first few hours of operation.
- Proper fluid: Use only the hydraulic fluid specified by John Deere for wet brake systems.
Related Part Numbers
| Part Number | Description |
|---|---|
| T228727 | Steel service brake disc plate (4-tang) |
| AT339059 | Service brake friction disk, right-hand |
| AT339543 | Service brake friction disk set, left-hand |
| AT339922 / T229406 | Transmission clutch disc kit (NOT brake parts – different system) |
Compatibility Verification
Before ordering, confirm compatibility with your equipment:
- Machine model: Verify your backhoe loader is in the compatible model list above
- Part numbers: Cross-reference with T228727 (steel disc), AT339059 (right friction), or AT339543 (left friction)
- Brake type: Confirm your machine has inboard wet multi-disc service brakes (standard on 310J/K/L/SJ/SK/SL series)
- Side: Note whether you need right-hand (AT339059), left-hand (AT339543), or both
- Quantity: Count the number of steel and friction discs per side (varies by model and brake configuration)
- Serial number: Provide machine serial number for precise fitment verification
If you are uncertain about fitment, send us your machine model, serial number, and current part numbers and we will help verify compatibility.
Ordering and Supply Information
| Parameter | Detail |
|---|---|
| Part Numbers Available | T228727 (steel disc), AT339059 (right friction), AT339543 (left friction) |
| Application | Wet multi-disc service brake for John Deere backhoe loaders |
| Compatible Models | 210K/L, 310J/K/L/SJ/SK/SL, 315, 325, 410 series |
| Origin | Made in China |
| Warranty | 6 months |
| Minimum Order | 1 piece per part number |
| 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 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 and rental fleets are accepted.
Browse our complete construction equipment parts catalog or read our guide to evaluating reliable parts suppliers before purchasing.
