Description
Function
The Haldex ModulT Air Disc Brake comes both left and right-handed. It is important that the correct hand is fitted in relation to the normal wheel/disc rotation.
The ModulT enhances a floating monobloc calliper C and an integrated adjustment unit which compensates for brake pad wear. The unit, which is actuated by the mechanism lever A, presses the inner brake pad B against the disc, which then causes the calliper C to slide laterally so that the outer brake pad D also comes in contact with the disc. The calliper moves on two stainless, lubrication free, slide pins E.
The large diameter single piston mechanism ensures even force distribution and support to the brake pad back plate. In addition, high efficiency and low hysteresis is achieved by the double roller bearings surrounding the lever. Single piston mechanism has a similar force distribution as previous generation twin piston mechanism, making it also suitable for tougher applications.
Inspection
The Haldex ModulT Service Manual states the importance of regular ADB function checks to ensure continued correct braking function in operation.
A Service Bulletin (SB DB 010L) has been issued to highlight the importance of this specific service check. If not already done, it is recommended that this check is carried out at the next available scheduled workshop visit. Failure to do so could compromise the continued correct operation of the ADB braking system.
Regular inspection:
- Check that the brakes function properly before driving and work effectively and smoothly.
- Check that the service and parking brake function is effective by trying to drive the vehicle with the service and parking brake applied.
- Make sure you have good lighting conditions.
- Inspect visible parts of the brake and its components and look for:
-
- Damage
- Collection of debris
- Corrosion
- Overheating signs
- Cracks in brake discs
- Unusual wear
- etc
Wear limits
-
Brake pads, min. lining thickness: 2 mm
-
Brake pad, max. uneven wear: ±1.5 mm
-
Brake disc, min. thickness: 37 mm*
Note. always refer to vehicle/axle manufacturers' recommendations.
Data
| Disc brake unit | DBT19LT | DBT22LT |
| 18 kNm | 20 kNm | |
| Max axle load | 9000kg* | |
| For wheel size | 19.5" | 22.5" |
| Max. operation force | 11 kN | |
| Friction radius | 149 mm | 173 mm |
| Max. brake cylinder stroke | 62 mm | 65 mm |
| Nominal brake ratio | 15.4 : 1 | |
| Mechanical efficiency | > 93 % | |
| Running clearance (min-max) | 0.7 - 1.1 | |
| Weight of complete disc brake unit, including pads | 28 kg | 29,5 kg |
| Disc | ||
| External diameter of brake disc | 377 mm | 430 mm |
| Total thickness - new | 45 mm | |
| Residual thickness - worn out | 37 mm | |
| Pad | ||
| Total thickness | 30 mm | |
| Backplate thickness | 8 mm | |
| Pad surface area (both pads) | 294 cm² | 318 cm² |
| Pad wear volume (both pads) | 603 cm³ | 636 cm³ |