How do you bleed the brakes on a 125 scooter?

How do you bleed the brakes on a 125 scooter?

Replacing the brake fluid on your 125 scooter is a relatively easy DIY job. It might be hidden away, but the fluid in your 125 scooter brake system should never be taken for granted.

Over time, the fluid degrades and overall performance can be affected, which is why regular changes are essential.

How to change the brake fluid of your scooter 125 in 9 steps:

  • Protect your paint 
  • Open the tank
  • Adjust your nipple
  • Crack and squeeze
  • Top up with cool liquid 
  • Watch the color change
  • Check for air
  • Repeat on the back
  • Perform a final check 

Consult your service manual for the manufacturer's recommended interval for changing the fluid. Place the 125 scooter on supports so that it is straight and level.

1. Protect your scooter 125 when you bleed it

Brake fluid is extremely damaging to painted surfaces, so prepare the area around the reservoir and handlebars for any possible spills. Cover the tank and the fork crown with an old towel or with a scooter apron. Always have a few sheets of shop towels on hand to quickly wipe up any drips that get on unprotected areas.

What you will need:

Towel ou scooter apron to cover your scooter

2. Open the fuel tank of your scooter 125

Wear protective shop gloves from this point on.

Remove the tank cover; it is sometimes held by a screw and a positioning bracket. When you remove the cover, do it slowly making sure that the diaphragm will not fall out. Sometimes it stays in the tank; if so, gently remove it and have a paper towel handy to catch any drops.

3. Adjust your nipple

Identify the size of the wrench needed to fit the bleed nipple, it is usually between 8mm and 10mm. Remove the rubber grommet that protects the nipple. The ideal is to use a ring wrench and place it on the nipple so that it can be loosened a few degrees without hitting anything. Install the hose from the bleed kit over the exposed nipple.

What you will need:

  • Key : This is a set of 12 ratchet wrench, thermally forged from industrial grade chrome vanadium steel with high hardness, corrosion resistance and long life. 

4. To bleed the brakes of a 125 scooter, apply pressure on the brake lever.

Carefully crack the nipple while exerting pressure on the brake lever. Squeeze the nipple and let go of the lever. Repeat until you see a clear flow of liquid without bubbles in the transparent part of the tube, then pump out the liquid, stopping squeezing the nipple each time.

5. Top up with cool liquid

Add fresh brake fluid as the level inside the master cylinder drops each time you squeeze the lever. Sometimes it is possible to speed up the process by adjusting the reach of your brake lever to the maximum. Do not move the lever too quickly, as it may blow up the drain hose and spray liquid all over the place.

What you will need:

6. Watch for the color change

Fresh fluid looks clearer than old fluid, so when you see a color change in the clear pipe from the bleed kit, re-tighten the nipple, check the master cylinder level is correct, and release the lever. Most of 125 scooters are equipped with two discs in the front, the opposite caliper must therefore follow the same technique to evacuate the old liquid. An extra pair of hands can help here.

7. Check for air

Once both calipers have been rinsed with new brake fluid, hold the lever one last time, crack the nipple and check that there are no air bubbles in the tube, then retighten. Repeat for both calipers. The brake lever should be firm and not spongy. Fill the reservoir to the correct level. Replace the cap, making sure the membrane is properly seated.

8. Repeat the operation at the back

The same technique can be applied to the rear brake. Use the purge kit and pump out the old liquid while adding new. You should know that many rear calipers are equipped with two bleed nipples. If so, use the nipple that is in the highest position, as this will help keep air out of the system.

9. Perform a final check

After all three calipers have been rinsed, check that the front and rear fluid reservoirs are filled to their maximum level. Then go around the 125 scooter and visually inspect the condition of other parts of the brake system, such as the pads, hose routing, banjo bolts and hose retaining clips, and look for any leaks.

Learn more about your scooters:

Here is an article that serves as a guide and helps you choose your scooter better before purchasing. For this, we give you the details on the characteristics and the different types of scooter.