How To Bleed a Moto Foot Brake (Surron, Talaria, E-Ride)
Tools Needed:
- Moto foot brake line kit
- Banjo bolts and copper crush washers (included with kit)
- Hand ratchet
- Impact driver (optional)
- 8 mm wrench
- 3 mm or 4 mm fuel hose
- Phillips head screwdriver
- Brake fluid
- Shop towels or rags
- Pad spacer (included with caliper)
Read This Before Starting Your Install:
Bleeding a moto foot brake is where most riders get stuck. You install the kit, squeeze the lever, and get nothing but a spongy pull and tiny air bubbles that won't quit. This guide walks you through a proper bench bleed on a Surron Ultra Bee foot brake setup, and the same exact process works for Surron, E-Ride, and Talaria moto foot brakes. They all bleed the same way.
This is for anyone who just bought a FactoryZ moto foot brake kit (or any not-bled foot brake kit) and needs to get fluid through the line and every air bubble out before the caliper goes on the bike. If you try to bleed it after it's mounted, you'll chase micro-bubbles for an hour. Bench bleeding fixes that.
You'll learn how to orient the 90 degree banjo at the master cylinder (including the difference between the stock HSK master and the upgraded YZ master with the nub), how to position the banjo at the caliper so it clears the swing arm and doesn't cook against the caliper body, the lever-and-nipple rhythm that actually pulls fluid through, and how to work the caliper to chase bubbles up to the bleeder. When you're done you'll have a firm lever, no hidden air, and a brake that's ready to install.
Install Steps:
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01
Attach the 90 degree banjo to the master cylinder
Grab your moto foot brake line and put the 90 degree banjo end on the master cylinder. The 90 degree banjo always goes here, facing up, whether you're running the stock HSK master or the upgraded YZ master. Slide a crush washer on, pass the banjo bolt through, add the second crush washer on the other side, and start the bolt by hand.
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02
Clock the banjo correctly for your master
If you're using the YZ master, there's a nub on the body. You want the 90 degree banjo sitting just on the near side of that nub, basically touching it. If you're using the HSK that ships with the kit, there's no nub, so line the banjo up perfectly straight with the master. Never clock it to the inside (it will hit your swing arm) or way out (you'll hit your ankle).
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03
Torque the master cylinder banjo bolt
Snug the banjo bolt with an impact if you want, then finish with a hand ratchet and make sure it's properly tight. If you don't get real torque on this, it will leak air at one of the two crush washer faces and you'll bleed forever chasing tiny bubbles that are actually coming in here.
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04
Install the banjo at the caliper
On the caliper, remove the banjo bolt and its two copper crush washers. Put the banjo bolt through the banjo in the correct orientation (don't flip it, or air will hide in the line), add a crush washer on each side, and start the threads into the caliper by hand. Never start these threads with an impact or drill, you'll strip something.
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05
Clock the caliper banjo and tighten by hand
Rotate the banjo so the brake line runs in the same direction as the pin, perfectly straight. Leave a little space between the line and the caliper body so heat from the caliper doesn't transfer into the line. Tighten this banjo bolt well with a hand tool. Under-torque here leaks at the crush washers just like the master end.
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06
Set up the bench bleed
Keep the whole assembly off the bike. Bench bleeding is the only reliable way to get 100% of the air out. Lay a couple of towels down on your bench, brake fluid will eat paint, jeans, whatever it lands on. Pop the cap off the master cylinder reservoir and fill it with brake fluid.
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07
Put a hose on the bleeder valve
Slip a piece of 3 mm or 4 mm fuel hose over the bleeder nipple on the caliper. Run the other end into a rag or catch container so that when the hose pops off mid-bleed, fluid goes into the rag instead of all over your bench.
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08
Crack the bleeder and work the lever
Use an 8 mm wrench to open the bleeder valve about 3/4 of a turn. The rhythm: open the nipple, push the lever down, close the nipple, then release the lever. Watch the fluid get sucked through the line each time you release. Don't just pump the lever fast, it won't work. Go slow. Open, push, close, release. Repeat.
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09
Keep the reservoir topped off
Watch the sight glass on the master. Don't let the fluid drop below it or you'll suck air right back into the system and start over. Top it off every few cycles until fluid is flowing cleanly out of the caliper hose.
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10
Work the caliper to chase bubbles
Once fluid is coming through, air bubbles will still be hiding at the top of the caliper, around the piston pocket, and near the bleeder. Move the caliper around, tilt it, and tap it lightly with the wrench to float the bubbles toward the bleeder. Hold the caliper so the bleeder valve is the highest point (it can be on either side of the caliper, doesn't matter which). Keep running the open-push-close-release cycle and you'll see the bubbles pop out.
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11
Keep the pad spacer in
Leave the pad spacer in the caliper during the whole bleed. It keeps the pistons from walking out and keeps you from hurting yourself or wrecking the bleed.
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12
Confirm the bleed is clean
Run the cycle a few more times after it feels good. You'll often see three or four tiny micro-bubbles pop out after you think you're done. When no more air is coming out and the lever feels solid, you're bled.
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13
Close the bleeder and cap the nipple
Tighten the bleeder valve all the way down with the 8 mm wrench. Wipe all the brake fluid off around the nipple so none ends up on the pads or rotor later. Slide the little rubber nipple cover back on.
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14
Top off the master and reinstall the cap
There's a rubber diaphragm (the "doohickey") that sits inside the reservoir cap. Before installing it, top the reservoir up to just at or slightly above the fill line so that when you seat the diaphragm, fluid displaces out instead of trapping air. If you cap it with air in the master, that air will migrate into the line later and ruin your bleed.
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15
Snug the reservoir cap screws
The cap screws are small Phillips head on purpose. Don't gorilla them. Light, even torque is all they need.
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16
Final re-check on both banjo bolts
After the system has sat for a minute, go back to the master cylinder banjo bolt and give it another check. If it turns a touch more, let it. Crush washers are called crush washers because you want to crush them so no air gets past. Do the same on the caliper banjo bolt. Then double-check the bleeder valve with your wrench. A bleeder that backs out mid-ride will dump fluid on your rotor and pads and destroy both.
Common Mistakes:
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Trying to bleed the brake after it's already mounted on the bike.
Pull the kit off and bench bleed it. It's the only reliable way to get every air bubble out of an empty line, caliper, and master.
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Under-torquing the banjo bolts at the master or caliper.
Snug both banjo bolts firmly by hand, then re-check after the system sits for a minute. Crush washers need to actually crush, or air will leak past them and you'll chase phantom bubbles forever.
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Pumping the lever fast like you're bleeding a car.
Go slow. Open the bleeder, push the lever down, close the bleeder, then release the lever. Watch the fluid get pulled through on the release stroke. Repeat one cycle at a time.
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Installing the caliper banjo bolt in the wrong orientation.
The banjo bolt goes through the banjo one correct way. If you flip it, air hides in the fitting. Match the orientation shown in the guide before threading it in.
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Capping the master reservoir with air trapped inside.
Fill the reservoir to the fill line or slightly above before seating the diaphragm and cap. Let a little fluid displace out. If you cap air in, it will eventually migrate down the line and undo your bleed.
FAQs
Can I bleed the foot brake after it's installed on the bike?
You can try, but it's the number one reason people can't get a clean bleed. When the line and caliper are empty and the kit is already on the bike, tiny air bubbles hide in spots you can't reach. Bench bleed first, then install.
Does this process work for Surron, E-Ride, and Talaria foot brakes?
Yes. The Surron Ultra Bee, Surron, E-Ride, and Talaria moto foot brake kits all bleed using this exact same process.
How do I know which side of the master cylinder nub the banjo goes on?
Only the upgraded YZ master has the nub. Clock the 90 degree banjo on the near side of the nub, basically touching it. On the stock HSK master there's no nub, so line the banjo up perfectly straight with the master.
Why do I keep getting tiny air bubbles that won't stop?
Two common causes. Either one of your banjo bolts isn't torqued enough and is sucking air past a crush washer, or you installed and tried to bleed on the bike instead of bench bleeding. Re-check both banjo bolts and bench bleed the system.
What size hose fits the bleeder nipple?
3 mm or 4 mm fuel hose slides right over the bleeder valve.
What happens if brake fluid gets on my pads?
It contaminates them. Wipe any fluid off around the bleeder nipple and banjos before the caliper goes on the bike. A leaking bleeder mid-ride can soak the pads and rotor and force you to replace both.