2009-2010 Honda CRF450r – Front Caliper Service

How To Service The Front Brake Caliper On Your 2009 – 2010 Honda CRF450r

2009 - 2010 Honda CRF4504 - Brakes - Front Caliper ServiceThe Tools You Will Need Are:

  • 12mm Socket
  • 10mm Socket
  • 5mm Hex Socket
  • 8mm Wrench
  • Screwdriver
  • Small pick
  • Non- Metallic Stiff Brush
  • Calipers
  • Brake Cleaner

The Parts You Will Need Are:

  • ’09-’10 Honda CRF450r Front Caliper Rebuild Kit
  • Fresh DOT 4 Brake Fluid
  • Rubber Grease

If you don’t have your rebuild kit yet, You Can Get Parts And Tools Through Our Partner Links HERE!

This front caliper rebuild should cost around $25 and take about 45 minutes to complete.

Brake fluid will damage almost everything it touches, so make sure you have your shop towels ready!

Related: 2009-2010 Honda CRF450r – Bleeding Brake System

Click Here To Open Brake Specs In A New Window


(Click to Enlarge)
Remove the brake pad pin plug, followed by the brake pad pin, and remove the brake pads, but leave the caliper mounted.2009-2010 Honda CRF450r - Brakes - Remove Bad Pin Plug
Pump the brake lever to extend the pistons, using the brake disc as a backstop.2009-2010 Honda CRF450r - Brakes - Pull Brake Pads
If you take your caliper off the fork and pump the pistons out, they may not extend evenly, like this one.2009-2010 Honda CRF450r - Brakes - Uneven Pistons
When the pistons have reached the brake disk, remove the banjo bolt, then remove the caliper.2009-2010 Honda CRF450r - Brakes - Even Pistons2009-2010 Honda CRF450r - Brakes - Remove Banjo Bolt
*Make sure to wrap the end of your brake line with a paper towel.*2009-2010 Honda CRF450r - Brakes - Wrap Brake Line


If your pistons are hard to remove, you can CAREFULLY remove them with pliers wrapped in electrical tape.2009-2010 Honda CRF450r - Brakes - CAREFULLY Remove Pistons
Remove the slide pin boots, bleeder valve, and piston seals.2009-2010 Honda CRF450r - Brakes - Remove Slide Pin Boots
Be very patient when removing the piston seals.Be Careful!


Related: 1997-2001 Honda CR250 – Front Master Cylinder Service


Clean every component with brake cleaner and a stiff brush.

2009-2010 Honda CRF450r - Brakes - Clean EverythiingThe components need to be free of brake cleaner residue before assembly.

You can wash everything down with brake fluid and a clean towel, or you can rinse and scrub with water.

I don’t recommend using water unless you have compressed air to completely dry the caliper body.2009-2010 Honda CRF450r - Brakes - Blow Out Caliper Body


Check the caliper components for any signs of noticeable wear or damage.

2009-2010 Honda CRF450r - Brakes - InspectOne of these pistons is pitted, so I will need to sand that down.

Check the slide pins for any rough areas that could bind.

If you feel anything, gently sand it with fine-grit emery paper until smooth.


Measure the inside diameter of the piston bore and the outside diameter of the piston.

2009-2010 Honda CRF450r - Brakes - Inspect The piston bore should be no Greater than 27.060mm, and the piston should be no LESS than 26.853mm.2009-2010 Honda CRF450r - Brakes - Measure Pistons

If your caliper bore and pistons are out of spec, they need to be replaced.

New Parts:

Before assembly, take stock of your new parts. Do you need parts?

I am installing an All Balls rebuild kit that includes a new set of slide pin boots, bleeder valve cap, pistons seals, banjo bolt seal washers, and slide pin.

2009-2010 Honda CRF450r - Brakes - New PartsMake sure to match the old parts with the new ones, so you don’t throw away something you need.

Soak your new piston seals in fresh brake fluid for 15 minutes before assembly.2009-2010 Honda CRF450r - Brakes - Soak New Seals

(Click to Enlarge)
Give the caliper bore one last wipe just to be safe.Be Careful!
Install the piston seals, immediately followed by the pistons.
Make sure your pistons are aligned as flat as possible, then install them in a twisting motion.
Install the slide pin boots, the short boot goes on the bracket, and the long boot goes on the body.2009-2010 Honda CRF450r - Brakes - Install Slide Pin Boots2009-2010 Honda CRF450r - Brakes - Install Other Slide Boot
Install the bleeder valve cover, then the bleeder valve.2009-2010 Honda CRF450r - Brakes - Install Bleeder Valve
Grease the slide pin boots with rubber grease,  assemble the bracket and body, and give the bracket a few pumps to evacuate any trapped air in the boots.2009-2010 Honda CRF450r - Brakes - Grease Slide Pin Boots
If everything feels smooth, pull the bracket off and install the brake pad retainer, then reassemble the caliper.2009-2010 Honda CRF450r - Brakes - Install Brake Pad Retainer2009-2010 Honda CRF450r - Brakes - Reassemble Caliper
Mount the caliper and install the banjo bolt with new seal washers. 2009-2010 Honda CRF450r - Brakes - Install Banjo Bolt
Banjo Bolt25 ft-lbs
Mounting Bolt23 ft-lbs

Related: 2009-2010 Honda CRF450r – Front Master Cylinder Service

If you have any questions or anything to add, please leave them in the comments or on our FaceBook page!

Fix Your Dirt Bike Logo


This site uses Akismet to reduce spam. Learn how your comment data is processed.