Tech Tuesday – How to Bleed Formula Disc Brakes

Mar 27, 2012
by Richard Cunningham  
Formula Brakes have been creeping up the status ladder as more riders discover that the unconventional looking Italian disc brakes are unmatched for stopping power, light weight and beautiful construction. Tech Tuesday walks you through the bleeding process for most of Formula’s disc brakes. The process also applies to its RX, Oro, The One, R-1 and Mega models.

Brake Bleeding Tips:

• As with all disc brakes, it’s best to remove the wheels and the brake pads BEFORE you get started so that there is no possibility that brake fluid, (or the barbeque sauce on your fingers) will contaminate the braking surfaces.
• Next, and we are adamant about this, DOT automotive brake fluid is caustic to paint and dangerous to your eyes and skin, so wear gloves and eye protection when handling brake fluid and bleeding brakes.
• Finally, Formula advises that you bleed its brakes off the bike. This good practice, because it allows you to secure the master cylinder/lever assembly and caliper in a position where the bleed ports are facing upwards. Formula recommends a simple fixture made from an old handlebar and a XC bar-end to hold the parts in position. I use a board and simply screw the parts into position with drywall screws. Today, however, we will do the job on the bike because some frames have hose routings that will not allow you to remove the caliper without disassembling the system.

What you need to bleed Formula RX disc brakes
What You'll Need:

- Strong rubber bands
- Spring clamps or duct tape
- Lint free towels
- Isopropyl alcohol
- DOT 4 or 5.1 brake fluid
- Formula or Avid bleed kit
- Brake caliper spacer (not in pic)
- Torx drivers
- 5mm, 2.5mm Allen wrenches
- Eye protection
- Nitrile Gloves
- Bike stand (not necessary, but very handy)

How to Bleed Formula Brakes

Remove brake pads and put pad retainer screw and c-clip in a safe place
Step One -Remove the wheels. Remove the spring clip from the brake pad retainer screw and then, with a Torx T20 driver, unscrew the retainer. Slide the brake pads out and place all the bits in a clean, secure location.

Insert caliper spacer
Step Two -Slide a clean caliper spacer into the brake pad slot and secure with a rubber band if necessary.

Locate bleed ports
Step Three - Locate the bleed screw ports on the caliper bodies. The ports will need to be pointing upwards and elevated to the highest level in order to ensure that air bubbles inside the caliper will evacuate properly. The front caliper can be left in place, but the rear caliper will need to be removed and clamped or taped in position to the swingarm.

Fill half way and then bleed air from syringes
Step Four - Fill two syringes about half way with DOT 4 brake fluid. With the hoses upward and the fittings covered with a towel, evacuate any air from the fluid. Set the syringes aside with the hoses tilted upwards in a secure place.

Remove plug and insert syringe fitting
Step Five - Wrap a towel around the caliper and secure it with a rubber band or similar to catch spilled brake fluid. Unscrew the bleed cap and be sure not to lose or damage the O-ring beneath it. Screw in one of the bleed syringes.

Remove bleed plug and screw in syringe
Step Six - Remove the brake lever and clamp or tape it to the handlebar grip so the bleed port points upward (Formula's R1 bleed port is already in position and the lever need not be removed from the handlebar). Unscrew the bleed port and then screw in the other syringe.

Bleeding the RX Front brake
Step Seven - Push brake fluid from the caliper side through to the brake lever side. It helps to pull the opposite syringe slightly to assist the process. Keep the syringes upright so air bubbles rise to the top and are not re-injected into the system. Repeat this action back and forth from the brake lever to the caliper four times, or until air bubbles no longer escape from the system.

Close the RX brake lever with a rubber band and pull a vacuum to free remaining air.
Step Eight - This is probably the most important step. To check for any trapped air in the caliper and lever, close the brake lever and secure it with a rubber band. Now, pull the syringe to draw a vacuum and then push gently to replenish fluid. Repeat this action a few times at the lever and at the caliper.

Unscrew the syringe and replace the RX bleed port plug.
Step Nine - Remove the syringe at the caliper and replace the bleed-port plug.
Tip: Look inside the bleed plug hole to check the fluid level. Add fluid with the syringe until the level reaches almost to the top of the threads to ensure the plug will not introduce air into the system.

Release brake lever and fill bleed hole with fluid
Step Ten - Pressurize the brake-lever syringe slightly while you release the rubber band holding the lever. Remove the syringe, check the fluid level as above, add fluid as necessary and then replace the bleed plug.

Clean system with alcohol and assemble brake pads with fresh gloves or clean hands
Step Eleven - Clean the entire system with alcohol and a clean towel. Remove the brake pad spacers. Before you install the brake pads and rear wheel, either switch to clean Nitrile gloves, or use clean hands to avoid contaminating the braking surfaces. Install the brake pads and replace the wheels

Once the brakes are installed and the wheels are on pump the levers until they come up hard.
Step Twelve -Step Install the brake levers and calipers. Pump the brake pads up to the rotors with a few lever strokes. The levers should feel firm. No? Repeat the process beginning with step eight and try again.
Tip: If the brakes still feel spongy after you have properly bled them, you may have damaged a bleed-port O-ring and are introducing air or losing fluid through the port. Replace the O-ring seals. Be sure to go for a short shake-down ride to test your brakes before you commit to a serious ride.

Did you find Tech Tuesday's Formula brake-bleed story useful?

Past Tech Tuesdays:
TT #1 - How to change a tube.
TT #2 - How to set up your SRAM rear derailleur
TT #3 - How to remove and install pedals
T #4 - How To Bleed Your Avid Elixir Brakes
TT #5 - How To Check And Adjust Your Headset
TT #6 - How To Fix A Broken Chain
TT #7 - Tubeless Conversion
TT #8 - Chain Wear
TT #9 - SRAM Shift Cable Replacement
TT #10 - Removing And Installing a Headset
TT #11 - Chain Lube Explained
TT #12 - RockShox Totem and Lyric Mission Control Damper Mod
TT #13 - Shimano XT Crank and Bottom Bracket Installation
TT #14 - Straightening Your Derailleur Hanger
TT #15 - Setting Up Your Front Derailleur
TT #16 - Setting Up Your Cockpit
TT #17 - Suspension Basics
TT #18 - Adjusting The Fox DHX 5.0
TT #19 - Adjusting The RockShox BoXXer World Cup
TT #20 - Servicing Your Fox Float Shock
TT #21 - Wheel Truing Basics
TT #22 - Shimano Brake Pad Replacement
TT #23 - Shimano brake bleed
TT #24 - Fox Lower Leg Removal And Service
TT #25 - RockShox Motion Control Service
TT #26 - Avid BB7 Cable Disk Brake Setup
TT #27 - Manitou Dorado Fork Rebuild
TT #28 - Manitou Circus Fork Rebuild
TT #29 - MRP G2 SL Chain Guide Install
TT #30 - Cane Creek Angleset Installation
TT #31 - RockShox Maxle Lite DH
TT #32 - Find Your Tire Pressure Sweet Spot
TT #33 - Three Minute Bike Preflight Check
TT #34 - MRP XCG Install
TT #35 - Stem Choice and Cockpit Setup
TT #36 - Handlebars - How Wide Affects Your Ride
TT #37 - Repairing A Torn Tire
TT #38 - Coil spring swap
TT #39 - Trailside help: Broken Shift Cable
TT #40 - Installing a Fox Float Air-Volume Spacer
TT #41 - Replace the Seals on Your 2011 RockShox Boxxer World Cup Fork
TT #42 - Clean and Lubricate Your Fox F32 Dust Wiper Seals
TT #43 - Thread Locker Basics
TT #44 - Install a SRAM X.0 Two-By-Ten Crankset
TT #45 - VPP Suspension Bearing Service
TT #46 - Rotor Straightening
TeT #47 - Finding and fixing that creak
TT #48 - Bleed and Service Magura Marta Disc Brakes
TT #49 - Cup and Cone Hub Basics
TT #50 - Install and Adjust Pedal Cleats
TT #51 - Cup and Cone Hub Rebuild
TT #52 - Converting Mavic Crossmax SX Axles
TT #53 - Cassette Removal and Installation
TT #54 - Cane Creek AngleSet Installation
TT #55 - American Classic Tubeless Conversion
TT #56 - Wider Rims Are Better and Why Tubeless Tires Burp Air
TT #57 - Pedal Pin Retrofit
TT #58 - Bleed RockShox Reverb Remote Lines
TT #59 - Cutting Carbon
TT #60 - Silence That Squeaky Disc Brake
TT #61 - Five Minute Wheel True
TT #62 - Removing Bike Rack Rattle
TT #63 - Inside Shimano's Shadow Plus Mech and How To Adjust It
TT #64 - Steerer tube length
TT #65 - Marzocchi 44 Rebuild
TT #66 - RockShox BoXXer TLC
TT #67 - Ghetto Tubeless Tire Inflator
TT # 68 - RockShox BoXXer Seal Replacement
TT #69 - Make a Ghetto Dropper Post
TT #70 - FSA Orbit Option Install

Visit to see their entire lineup of tools and lubes


  • + 60
 nice write up! BUT!!! i vote for more tech tuesday videos!
  • + 11
 ya i think vids are way better
  • + 12
 +1 on the videos!
  • + 17
 these brakes are fucking good,i hav them.thanks 4 this
  • + 6
 Another Tech Thuesday which is actually usefull for me, becouse i have never had Formula brakes yet, but as for my friends ask me to bleed their brakes, or as usually service their whole bike - it can be usefull for me. Just like any bike part it isn't UFO tech or difficult - i can see synonym in way to do this with Avid brakes. Thank you pinkbike!
  • + 6
 i'm sorry but i talket directly with Formula here in italy, and they say that you DO NOT close the brake when pull the upper siringe because there is a thin membrane inside the brake that close it when do the vacum, i bleed my the one in this way and they are soooooo much better Wink
  • + 4
 i agree, this 'membrane' you are referring is extremely sensitive, and all the moves must be done very gently. I had to do this 3-4 times to get it right, but then the braking power is like 100%. Also. the spring clamp helps a lot, nice!
  • + 3
 I actually wouldn't have done step eight, but I read about the tip in the Formula brake bleed PDF while I was researching the process. It was the winner step, as a number of air bubbles evacuated from the caliper and the reservoir when I closed the lever and drew a vacuum. You were correct on taking care not to damage the MC reservoir bladder though. Good tip! RC
  • + 1
 Correct, it should be noted that this process does pull bubbles out, but one should only pull very gently on the syringe as you can actually pull bubbles past the membrane, and possibly dislodge the membrane.
  • + 6
 Pinkbike just read my mind.milooked this up yesterday on the formula website!! crazy stuff
  • + 3
 Strong clamps? Rubber bands? Toxic fluids? Screw the brakes into a piece of wood? Careful about some cryptic membrane?
What a nightmare. I miss my old Shimanos!
Anyhow, it worked, as awkward as it was compared to the simplicity of a shimano bleed. Thanks much for this tip it was super helpful.
  • + 3
 Surely bleeding the brake this way will mix the new and the old fluid (Step 7)? I would have thought you would want to remove all of the old fluid first and replace it with fresh fluid?
  • + 1
 It depends on how recently you've bleeded before. A full renewal of all fluid is not necessary each time.
  • + 5
 just buy the elixer's, they leak out the old fluid every few weeks, then top er up withe blue loctite and no more leaks!!!!
  • + 2
 There's a similar run down here, though I found some of the emphasis on the singletrack guide a little more interesting because following the Formula instructions were only getting me so far.
  • + 1
 Thanks for the write up, but for the most part, it seems as if bleeding/maintaining most hydraulic systems (bike brakes, dropper posts, car brakes, tractor hydraulics...) is pretty similar in principle and practice; make sure you have the right fluid, stay clean, purge all the relevant moving parts of air and flush the system with new fluid every now and then.

How about a wheel building video?
  • + 1
 "Next, and we are adamant about this, DOT automotive brake fluid is caustic to paint and dangerous to your eyes and skin, so wear gloves and eye protection when handling brake fluid and bleeding brakes."
*cough *cough shimano uses mineral oil ftw
  • + 2
 Yep Shimano brakes are my favorites but the mineral oil does have a down side. In real cold temperatures they get a short squishy lever throw.
  • + 1
 Really straightforward. However: 2nd time my front needed bleeding (dealer's tech did it 1st on warranty) evidence of fluid where hose leaves lever. removed 8mm a/f hose nut and hose, a port is visible within threads. this 'weeps' every time lever is pressed. what we now need is page 2: how to strip and refurb a brake lever/actuator cylinder assy!
  • + 3
 Step one: Remove from bike
Step two: Throw away the Formula brakes
Step three: Fit Shimano brake
Step four: Ride for years problem free!!
  • + 1
 The problem with step 8 is that most syringes, especially the cheap formula or avid luer lock syringes, almost always leak and allow air through when you try to create a vacuum. You might get away with this on the first use of a new set if you're lucky.

Edit: I'm complaining about the issue of poor syringe quality and not your process really. If you have syringes that won't leak you are golden.
  • + 1
 All of us should follow the same way as Avid's.
I though Formula have no "bleed block" or "caliper spacer" but compatible with Avid's?

I always bleed following this vid that makes my Oro Bianco very firm.
But I'm struggling to get freestroke shorter.
Although overfilling fluid causes some damages on internal system of lever, is there any tips for that?
  • + 3
 You should dee-gas the brake fluid before you bleed the brake, because when you pull on the syringe it creates vacuum and the brake fluid bubbles up.
  • + 1
 Can't do that on the Formula bleed kit (but you can on the Avid one for example) unless you put some sort of ghetto clamp on it.

Even if I bleed Hope brakes, I still put some DOT in the Avid bleed kit seringe and degas it ^^
  • + 4
 Tip: with the formula kit (no clamps), just put your gloved finger tip over the end and pull up on the syringe to degas before you screw it into the caliper or master cylinder. Not TOO ghetto and works as well as the clamps.
  • + 3
 thanks for this most informative but video would be more help as even small details that could be thought self explanatory people may forget.
  • + 2
 Do a bleed guide for HOPE TECH BRAKES and how to stop them from being squidgy even after bleeding them properly!
  • + 2
 are do doing the final step i seen youtube? it works for me. when you've bleed the system the usual way ( press lever while opening caliper nipple, then close nipple when lever fully depressed and top up reservoir as lever returns etc ) until all air seems to be out of system and you think your done, THE MOST IMPORTANT bit is to 3/4 fill reservoir, refit badder not bothering to chase the air from under it and fit the cap. slacken the lever bolts and position the lever towards the floor ( completely vertical ) and press the lever hard and fast about 20 times while tapping the lever body to vibrate it ( reason being because of the lever piston/inlet design air can be trapped ). Then swivel the lever back completely flat (horozontal) and remove cap and bladder again, fill thereservoir to the top roll the bladder on to chase any air out and refit top cap, Your brakes should feel sweet every time then. THIS IS FOR HOPE TECH BRAKES.
  • + 3
 It says "oval piston tech"... aren't these Formula RO?
  • + 3
 Secret upgrade. RC
  • + 2
 I think R0 caliper with RX lever(including TFRA option)

So sick!
I want that.
  • + 1
 Am I missing a bunch of text not showing on my screen or a video link? A few pics and no description at all about the process. Did this get edited or something?
  • + 2
 Bled my RX's today. Worked like a charm Wink
  • + 2
 Formula needs to work on the bleed ports. What a hassle.
  • + 1
 Thanks mate,great instructions. My Formulas are now better than ever,keep up the good work.
  • + 1
 Sorry if I sound stupid but can you tell me what bleed block is used after removing the pads? Cheers.
  • + 2
 Allmost the same way you bleed a reverb seatpost tricky
  • - 1
 Oh sweet. I will just go and grab my Formula brakes now.
Oh wait. I'm way too cheap to buy some Frown
Yay for mech disc brakes!
  • + 1
 DOT 4 or 5.1 brake fluid? Doesn't Formula say ONLY DOT 4?
  • + 2
 it doesn`t really matter.
  • + 0
 now make a tech tuesday about avid bleeding without the expensive bleeding kit... IMPOSSIBRU!
  • + 1
 you can buy one on ebay. they are pretty cheap... you can almost everything bleed with them.
  • + 0
 this guy actually works for a living....nice
  • - 2
 I have these on my bike still looks to hard so I will just have the shop do it
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