Fitting instructions are common to N Series (Meritor) calipers - NR225, NT225, NV225, NX225, NV195 & NX195.
Do not use air wrenches or hammers. Their use will damage the product, prevent correct function and will void the warranty.
Text in green is offered as advice.
If you have any questions about the fitting instructions, or require further advice, please email firstname.lastname@example.org
1. Ensure the vehicle is securely chocked before releasing the parking brake. Remove the wheel in line with the manufacturer's recommendations. Cage the spring brake or use a minimum hold pressure of 90 psi (6 bar). Remove the air chamber and disconnect the pad wear sensor cable (if fitted) from the caliper.
2. Make note of the pad wear warning indicator (PWWI) cable arrangement (if fitted) and remove the pads and retainer. Remove the pad retainer by removing the hexagon head bolt. Replace used parts with the new ones provided. Remove both pads and springs and visually inspect - replace if worn or damaged. Remove the old brake assembly - use suitable lifting equipment for the brake assembly. Visually inspect and, if necessary, clean the disc - replace if worn or damaged.
3. Remove the new brake assembly from the packaging - use suitable lifting equipment for the brake assembly. Check that the new brake assembly corresponds with the one that has been removed.
The pre-assembled pad retainer can be used to lift the caliper if done with care.
Never hold the caliper with your fingers between the caliper and the carrier - there is a risk of injury.
4. Lower the brake assembly over the disc and tighten the carrier fixing bolts in line with the vehicle manufacturer’s recommendations.
5. Slide caliper inboard and insert inner brake pad and spring.
6. Slide caliper outboard and insert outer brake pad and spring.
7. Turn the adjuster clockwise until the pads come into contact with the disc - do not exceed 25 Nm torque.
8. Turn back the adjuster 3 clicks and check the pad-to-disc running clearance.
9. Check for free rotation of the disc. Refit the adjuster cap.
10. Locate the new pad retainer in the slot in the caliper and depress to enable fitment of the hexagon head bolt. Tighten the bolt to 33-40 Nm.
11. Reconnect the pad wear sensor (where applicable), tightening the hexagon head bolt to 33-40 Nm.
Ensure the pad wear sensor is clean and free from dirt and moisture.
12. If applicable, refit the pad wear warning indicator (PWWI) cable and clips in the same orientation as when removed.
13. Remove the adhesive tape in the area of the air chamber attachment. Take care that no dirt enters the brake caliper.
14. Visually inspect and if necessary clean the air chamber mounting and sealing surface - replace if damaged.
If the air chamber seal protrudes less than 3 mm the brake chamber must be replaced.
If there are signs of rust on the air chamber pushrod and on the lever of the old caliper replace the air chamber.
15. Refit the air chamber in the same orientation as when removed, in line with the vehicle manufacturer’s recommendations. Tighten the nuts to 180-210 Nm (unless specified differently in the vehicle manufacturer’s recommendations).
In order not to tilt the air chamber during its attachment, the nuts must be gradually tightened symmetrically with a suitable tool.
16. Replace the wheel in line with the vehicle manufacturer’s recommendations. Uncage the spring brake and apply the parking brake prior to removing the chocks from the vehicle. After releasing the parking brake, apply the brake 10 times then road test the vehicle.