How to Change Dirt Bike Brake Pads

Step By Step

1. Open the reservoir, cover the paint

   Turn the bars so the reservoir sits level and lay a rag over the tank and fender. Remove the reservoir cover and membrane. Pushing the pistons back sends fluid up into the reservoir, and you need to see it.

   • Screwdriver
   • Rags

   Careful. Brake fluid corrodes paint and plastic. Rinse any spill with water right away.

2. Push the pistons back

   With the old pads still in, push the pistons straight back into the caliper. KTM has you tilt the caliper gently against the disc to do it. Watch the reservoir and draw some fluid out if it gets close to the top. On the rear, don’t lever the caliper against the spokes.

   • Flat plastic tool
   • Syringe or rag for extra fluid

   Shop tip. Yamaha’s method avoids pushing old fluid back up. Fit a hose on the bleeder into a bottle, open the bleeder, push the piston in, then close the bleeder (5 Nm on a YZ). Never reuse that fluid.

3. Remove the caliper and pad pin

   Undo the caliper bolts and lift the caliper off the disc. Then pull the pad pin. On a KTM, take out the cotter pins first. On a Yamaha, remove the pin plug and loosen the pin before the caliper comes off.

   • Socket or hex key
   • Pliers

   Pad pin

   Bike	Spec	Source
   KTM / Husqvarna / GASGAS	Pin with cotter pins	KTM 450 SX-F 2024 owner’s manual, PDF p. 104-105
   Yamaha YZ250F / YZ450F	Pin 17 Nm, plug 2.5 Nm	Yamaha YZ250F 2026 owner’s service manual, p. 4-21

   Check your manual for the pad pin torque and how it is retained.

   Careful. Don’t squeeze the lever with the caliper off. The pistons will pop out of the bores.

4. Pull the old pads and clean

   Slide the old pads out. Clean the caliper and bracket, and scrub around the piston seals with an old toothbrush and soapy water. Check the spring plate and pad slide plate are seated, and that the pin isn’t worn or bent.

   • Old toothbrush
   • Rag

   Shop tip. Galfer points out that clean pins, slides and springs let the pads pull back fully when you let go of the lever, which stops them dragging.

5. Fit the new pads and pin

   Fit both new pads, always as a pair, with their tabs in the caliper recesses. Push them against the retainer spring and slide the pin through both. Fit the cotter pins or tighten the pin and its plug. On a KTM rear caliper, the decoupling plate goes on the piston side pad.

   • Torque wrench
   • Pliers

   Use the pad pin from the table above.

   Careful. Handle new pads by the edges. Pads soak up brake fluid and grease, and a contaminated pad won’t grip.

6. Refit the caliper and torque it

   Slide the caliper over the disc without forcing it. Fit the bolts with thread locker if your manual calls for it and torque them to spec. These bolts hold your brake on the bike.

   • Torque wrench

   Front caliper bolt torque

   Bike	Spec	Source
   KTM / Husqvarna / GASGAS	25 Nm (18.4 lbf ft)	KTM 450 SX-F 2024 owner’s manual, PDF p. 105 (M8, Loctite 243)
   Yamaha YZ250F / YZ450F	28 Nm (21 lbf ft)	Yamaha YZ250F 2026 owner’s service manual, p. 4-21

   Caliper bolts are safety fasteners. Use the torque from your manual.

7. Pump the lever until it is firm

   The pistons are pushed all the way back, so the first pulls do nothing. Pump the lever or pedal until the pads touch the disc and you feel a firm pressure point. Check the wheel still spins freely.

   Careful. Never ride off before the lever is firm. The first squeeze on a fresh pad change goes straight to the bar.

8. Set the fluid level

   With the lever firm, set the fluid to the mark with fresh fluid of the type on the cap, or take out the extra if you added too much earlier. Refit the membrane and cover, and rinse any spill with water.

   • Brake fluid
   • Rag

   Brake fluid level

   Bike	Spec	Source
   KTM / Husqvarna / GASGAS	5 mm below the rim	KTM 450 SX-F 2024 owner’s manual, PDF p. 106 (DOT 4 or DOT 5.1)
   Yamaha YZ250F / YZ450F	Above the min mark	Yamaha YZ250F 2026 owner’s service manual, p. 3-25 (DOT 4)

   Fill to the mark on your reservoir with the fluid type printed on the cap.

9. Bed in the new pads

   Make sure the disc is clean and dry. Galfer’s method is a set of easy stops from 10 to 15 mph, building in steps of about 10 mph up to 40 to 50 mph, repeated two or three times. Then ride normally. Follow your pad maker’s sheet if it says something different.

   Shop tip. Bedding lays a thin, even layer of pad material on the disc. It helps prevent glazing and gives a stronger, smoother bite.