How to rebuild your master cylinder Disassembly and Assembly

How to disassemble, rebuild and reassemble master cylinders commonly found on motorcycles, powersports, atvs and other vehicles.
Thank you for watching. Please subscribe and share my work!
Tool Links:
If I can ever be of service to you, here is a video explains how to connect with me.Β 

Keep Wrenching,
Shane Conley
Below are some links that help support me and my work. Please subscribe and share these videos to make a difference in education!

Shirt/Stickers link:

Follow us!





Free Mechanic info, tool reviews, and β€œhow to” videos newsletter sign up:

Amazon Tools:

Click the links to playlists: (entire list link is the last one)

Harley EVO:
Harley Twin Cam:
4-Stroke Engines:
2-Stroke Engines:
Small Engine:
Every Mechanic Should Know This Training”:
Wheels, tires, brakes:
Fuel, air, intake:

All playlists by type:



50 thoughts on “How to rebuild your master cylinder Disassembly and Assembly

  1. Made NO MENTION of the importance of the 2 internal holes / channels being checked and verified clean and clear. The pressure-side hole gets notoriously dirty, corroded, and plugged… and is one of the most common failures of brake master cylinders.

  2. Thanks guys, what a great video!
    I have one question though, what causes the small bubbles to form when pressing the lever? My bike just started doing and Im not sure how to troubleshoot it… Thanks for your help!

  3. Very informative!
    My piston gets stuck and won't move once I get that last seal into the bore, likes it's too big. So do I have the wrong seals or is the spring too weak and needs replaced? It takes so much force, like alot, to push the piston/seal in and just gets stuck and won't return, thus I can't build any pressure at all. Thanks in advance for any advice or thoughts. πŸ™‚

  4. I have a 1987 kawasaki 454ltd and I am trying to find a rebuild kit or just the cup piston which is 5x13x4mm any suggestions if another model motorcycle uses the same size piston? And the sight glass was also junk so I need to find one it's 21mm diameter and uses a o ring seal.

  5. As a full time teacher, I gotta say… My hat's off to ya. Good job! πŸ™‚ Especially when it comes to the students (myself) understanding the overall concept..

  6. Good job showing which way the seals go on in case our mind is on some Playmate of the Year when dissasembling. Also, showing the snap ring's square edge facing outward (being a machinist and assembling diff things, i figured that out yrs ago). I've never had to buy new seals. Clean them up and reassemble. Never had one leak yet; same goes for the piston caliper seals. As long as they're still flexible and free of cracks/deep pits, they work.

  7. I thought you were going to stab your self with that pick when you were installing the o-rings. Use your pocket screwdriver you will thank yourself when you slip and its not through a finger

  8. i have a 06cbr600rr. when i roll the bike foward the front brake lever loses tension but when you pump it a few times it returns how can i fix this?

  9. hi Shane…..hey great vid …..I just pulled / pushed my front brake piston in an it stuck as no fluid was in reservoir an pads very worn out. Which one of the rebuild kits here on your channel ( below screen ) work for my 1982 CB 750 Custom ….thanks an thumbs up to ya buddy….
    Lake George, NY

  10. I completely drained out fluid from functioning front brakes. Now i added fluid but it does not pump fluid down to caliper. Brake lever does nothing. No resistance. Any suggestions?

  11. Changed front brake pads on 09 rebel 250 and the master cylinder leaked a small amount from the small piece that is pushed in by brake lever when squeezed. Am I okay or do I have a proplem?

  12. Hi Shane, I love your videos and learn many things.I would like to ask you s.thing.I have DR 350 Suzuki 1995 mod.I just made a hole on front dumper with drill:( while I was trying to take out a broken bolt.I do not know if I can stick it or repair in anyway.Can you recommend me s.thing.thx and keep doing this wonderful job.

  13. Thank you Shane, I'm just in the process of renewing an '84 Aspencade's clutch master cylinder and this explained it better than the Honda manual! Great tip about fluid level and pad wear, in 25 years of riding and maintaining that never crossed my mind!

  14. Excellent video. I used it to rebuild my master brake cylinder on a Yamaha Roadstar with no problems.
    Can you possibly do a video on recharging the braking system after the rebuild with any tips to make the job quicker and easier ? It took me quite a while to get the brake pressure back up.

  15. DOT 3 and 4 are water soluble. I always wash these things with hot water and soap. I use the baby bottle brush from Walmart to clean them. if really grimy I use my sonic cleaner with simple green, rince really good. sometime I put it in the dish washer. Then I dry with an old hair dryer, let it cool then put it back together, viola, it works

Leave a Reply

Your email address will not be published. Required fields are marked *