'Standard' Brake Cylinders
'Slotted Clevis' Brake Cylinders
Standard 'Spring Return' Brake Cylinders
Slotted 'Spring Return' Brake Cylinders
Standard 'Square' Actuator Assemblies
Standard 'Round' Actuator Assemblies
Air to Hydraulic 'Converter Kits'
Dual Supply' Pneumatic/Hydraulic Actuators
'Standard' Pneumatic Service Brake Chambers
Be-spoke hydraulic cylinders / “rams”
Spares & Accessories for Standard Brake kits
‘Weld On’ Axle Brackets
Standard ‘Spring Return’ Brake Cylinders
A standard spring return brake cylinder used on agricultural trailers, is a single-acting displacement type hydraulic actuator, incorporating an internal compression spring which returns it to the “brakes off” position. It plays a critical role in the trailer braking system, particularly for systems where safety and simplicity are key (often found in tractor-trailer setups).
Our Standard ‘Spring Return’ Brake Ram sizes are as follows:
| Order Ref No. | Part Description | Rod Dia | Body Dia (mm) | Body Length | Stroke (mm) | Closed / Open Ctrs | Thrust @100 Bar |
|---|---|---|---|---|---|---|---|
| SRBR20 | 20MM S/RETURN BRAKE RAM | 20mm | 38.10 | 200mm | 73 | 244 / 317 | 3142 N |
| SRBR25 | 25MM S/RETURN BRAKE RAM | 25mm | 41.28 | 198mm | 75 | 252 / 327 | 4909 N |
| SRBR30 | 30MM S/RETURN BRAKE RAM | 30mm | 50.00 | 210mm | 75 | 263 / 338 | 7070 N |
| SRBR35 | 35MM S/RETURN BRAKE RAM | 35mm | 53.98 | 221mm | 75 | 273 / 348 | 9622 N |
Key Characteristics:
- Displacement Type: Moves fluid by pushing a rod/piston directly.
- Single Acting: Hydraulic pressure extends the rod/piston; the spring handles the return process.
- Internal Compression Spring: Returns the rod/piston (and thus the brake mechanism) to the “brakes off” position when hydraulic pressure is released.
- Fail-Safe: If hydraulic pressure is lost (e.g. trailer detaches), the brake is released by default, avoiding dragging.
How It Works in a Trailer Brake System:
| State | Hydraulic Pressure | Spring Position | Brake Status |
| Braking | Applied | Compressed (loaded) | Brake ON |
| Released | Removed | Extended (relaxed) | Brake OFF |
- When braking: The tractor sends hydraulic pressure to the trailer’s brake cylinder, extending the piston and engaging the trailer’s brake shoes or pads.
- When braking is no longer needed: Pressure is released, and the internal spring automatically retracts the piston, disengaging the brakes.