Front Master Cylinder Disassembly and Rebuild Procedure

This video will show you how to disassemble and rebuild a motorcycle's front master cylinder with some very basic tools. While this was done on a master cylinder from a 1983 Honda CB1100F, the procedure will be very similar for many other motorcycles.

[@Jimmers131005]

After buying 2 separate snap ring removers and struggling with it for an hour, I found your video. Using the "pick" I got it out in 20 seconds. Thanks so much!

[@willatkinson7958]

Awesome quality of the video in every way possible. Clear, concise, not hurried, and complete. Well done and thank you.

[@ceemore5862]

This is the only video I’ve seen anywhere that mentions cleaning the pressure release hole. Thank you for the video and guitar string idea.

[@tomscyclerecycling8242]

Glad to hear that my video helped! Thanks!

[@ceemore5862]

@@tomscyclerecycling8242 The front brake on my 1993 FXLR has been dragging really bad and I’d have to stop and loosen the bleeder to relieve pressure. I followed your instructions and pulled the handle looking for an air bubble from the pressure release hole and got nothing. Then using a guitar string (g string to be exact) I cleaned out the pressure release hole and pulled on the handle. It might sound strange but I’m happy to say I was squirted with brake fluid. I was thinking I need to take it apart and rebuild but I think it’s good now. Great video, sir.

[@markmulhern697]

There are lots of videos out there, but they were all missing a key point, none of them talked about that return hole being crucial to be clear, I was having an issue caused by the hole being blocked, your explanation and seeing you work on it made all the difference. Tanks Tom

[@tomscyclerecycling8242]

I'm happy that you found my video helpful Mark. May you have many trouble-free miles of riding now that you have it sorted out.

[@tomkerxhalli1783]

Thanks Jim. I'm really glad my video saved you some time. The intent of all my videos is to show how to do common motorcycle repairs with a minimum of tools. I say keep it simple! Tom

[@christheriot5321]

This video was very helpful. Thank you for the time you put into it. Your work shows in the finished product.

[@russelltmobley8262]

Thank you Tom. clear, concise, simple.

[@UnderseaCaveman]

BTW, I would like to mention CRITICAL....on your master clutch cylinder a blocked return port will cause you to completely loose your clutch (full slippage) until the hydraulic fluid cools off again and contracts and also full clutch spring pressure exercision on the wet clutch plates. I just realized that is where all my slipping clutch problems reside. Thanks for great video. Note Hydraulic fluid in clutch system gets much hotter than brakes and sustain temp (up to engine and oil temps....~400F) until engine cools sufficiently (like waiting about 80 minutes).

[@patrickphippspa584]

Well-made and handy video...now, out to my own to rebuild. Thanks!

[@wingrider1004]

Excellent video.

[@SidecarBob]

If you don't have a pin vise or a guitar string handy, a sewing needle works well for cleaning out the return hole.

[@alexholland3811]

This is going to help with an FJ1200 Master Cylinder. Thanks. If I could add one suggestion. While you were rebuilding the MS, it may help to take a picture of all the parts, laid out on the bench, in the order and placement of how they may be in the cylinder. For instance you inserted the spring and rubber end but I was not sure which end went into the MS. I am guessing it would be obvious once I went to put them together but I could not see if the rubber end went in first or if the spring end went first and the rubber end piece was further out. Seeing all the parts lined up, as they would be in the bore, takes away any doubt of how things should be inserted. in any case, a fine video that answers most of my questions. thanks Alex

[@tomscyclerecycling8242]

Thanks Alex. All good points. I think you'll have all the missing pieces of your puzzle when you pull apart your master cylinder.

[@jonathansolanes7850]

Fantastic! Great class! Thanks!!

[@petebarber9287]

great class... well taught...

[@fazerthofzs9123]

nice 1 Tom great video thx

[@johnhabovick7163]

outstanding video and explaination

[@JasonJFlippingLife]

Great detailed video. You've got another subscriber.

[@tomkerxhalli1783]

Thanks Jason. I have a view video almost ready to release, so keep an eye out for it. Tom

[@xs-1b415]

Great video!

[@SucceedingInFinTech]

Outstanding.

[@barcusful]

thanks for sharing.

[@tomkerxhalli1783]

The wide end of the spring goes in first. The narrow end had the rubber cap positioned with the flat end pointing out toward the piston.

[@lamrock0]

I messed this one up, couldn't figure out why I could get fluid through the system :P One of my more frustrated moments that.

[@segattoma]

thank you good video

[@SeraphimKidd]

This was a great video!

[@tomscyclerecycling8242]

Thanks, Ryan. I hope you found it helpful.

[@Dave-in-France]

Hi Tom, first of all thank you very much for taking the time to make this video and helping to de-mystify brake master cylinders. I'm going to do this work on my Triumph Tiger and I have 1 question please; Why is there what looks like a worm gear on the piston. I ask this question because my brake lever comes a long getting close the 'bar, before firming up. I was wondering if this 'worm gear' was some way of adjusting the length of travel of the lever? Cheers Dave

[@hillton2180]

Nice one thanks

[@CanadianMapleleaf]

Thank you

[@Brillig2]

This looks like maybe what I need to do. I have a Hyosung GV650 that just started showing signs of issues with the master cylinder. If I compress the lever normally, it sort of jerks instead of having a smooth motion. If I exert pressure on the lever sideways in addition to normal brake compression direction, I get smooth action. I did some playing around to see if the jerkiness originated at the handlebar cylinder or the wheel end, and I'm pretty sure it's at the handlebar end. I was all set to order a new master cylinder, but maybe I just need to rebuild it or maybe even just take it apart and clean it. Seems like I run the risk of damaging rubber parts if I just try to clean it, though, eh?

[@HPSFRoadrunner]

Nice 'how-to'. I wish I had watched this before buying my kit because I think my master is fine except for the return being blocked. Another thing you can use to clear that return line would be a welding torch cleaning tool. Not sure which gauge to use though.

[@SHAWZY1973]

Hey Tom, great video... wondering if you could help.... my res has a clear plastic circle in the bottom which covers the return hole.... how do i remove this without damaging it??? Many thanks in advance Dave UK... P.S. the bike is a 2000 model XR400

[@CrashHUN187]

THX

[@happysawfish]

Awesome. Like the workshop and format, and the magnified closeup! For refinishing the housing, do you prime it for painting? What type of paint do you use? Is there a particular paint that better resists brake fluid? Thanks

[@tomscyclerecycling8242]

I didn't paint that master cylinder, I powder coated it. After disassembly and cleaning, I media blasted it with aluminum oxide but plugged the bore to keep the media out. Then it was washed, dried, and outgassed before powder application. Masking and plugging was done prior to powder coating, to prevent getting powder in areas it doesn't belong. Then it was cured in the oven for a hard, beautiful finish that's resistant to brake fluid. Glad you liked my video and thanks! Tom

[@tomkerxhalli1783]

Did you replace the internal parts of the master cylinder? The seals may be worn and aren't pushing the brake fluid. Make sure they're in good shape and properly installed.

[@ketankadam5669]

Hi tom, I got a little packet of grease with the rebuild kit! Should i use it on the rubber seals on the piston? Using grease in the hydraulic system seems odd to me?

[@tomscyclerecycling8242]

Yes - once the seals are in place in the caliper, put some of the grease on your finger tip and spread it on the surfaces of the seals. It's a special grease formulated just for this purpose and is better than using brake fluid.

[@PHANTOMPHISH1]

will this be the same for the clutch mc?

[@mauipalmandtreecare]

do they give you a new fluid level window to replace the old one?

[@tomkerxhalli1783]

No, Honda never intended them to be replaced but I sell replacements and also have a how to video here showing how to replace it. Go to my KZbin channel to see it and you can contact me through my Web site for the new window.

[@antoniobejarano5283]

Very good video. THX I have a Suzuki 1982 GS850G with what I believe is a problem in the master cylinder (rectangular reservoir). I have no pumping pressure despite everything looking good inside the cylinder. I check for the return hole you mentioned but I only have one hole.The brakes were working before but the brake pads were too close to the brake disk. After I cleaned the master (it is old) I have the no pressure problem. Any ideas? THX

[@SidecarBob]

1) Your master cylinder has to have a return hole. They are sometimes very tiny and can be difficult to see if completely blocked. 2) Did you bleed the brake after you rebuilt the master cylinder? If you don't bleed all of the air out you will never get it to produce pressure at the pads.

[@thirdGEARchirp]

Sidecar Bob I have the same issue. I rebuilt the lever on my 79 GS1000l. I bled the lines and not matter what the fluid just moves around the master cylinder. It does not seem to get pushed down the line.

[@SidecarBob]

thirdGEARchirp More information is needed. Did you install a rebuild kit or did you just clean it out and put the old parts back in? If you didn't replace all of the rubber parts you wasted your time. And how are you bleeding the lines? There are several methods and depending on which one you use and how you are doing it you could be causing your own problem. This needs more instruction than is feasible in the comments for a video so I recommend that you find & join a forum that specializes in bikes like yours and ask there.

[@bigal3494]

Hi,can I ask,which. way does spring go in,black cap first or open spring first,thanks

[@tomscyclerecycling8242]

The wider end of the spring goes in first, with the rubber cap/seal in the narrow end. You'll see a hole in the steel cap on the narrow end. That lines up with the little rubber nub on the inside of the seal.

[@Living4hride]

Hey Tom, how would I remove plunger if frozen in the front master cylinder.

[@tomscyclerecycling8242]

Hi Erik. Connect it to another master cylinder through the banjo hole and you will be able to pump it out. I just had to do this the other day with one that I'm restoring for a customer. Just make sure that the snap ring is out and that the plunger is pointing away from you!

[@AlvaroGarcia-kf3ih]

Hi do you know what's the part number on the ones the have a bigger piston I purchased a rebuild kit but it was smaller then my original piston

[@tomscyclerecycling8242]

If I know the year, make, and model of your bike, I might be able to help.

[@KWAKA8]

Nice vid, tho didn't see which way the spring went in:(

[@walternarcisse7692]

Without my battery in do my front brakes still suppose to work

[@MrCbell57]

This might not find it's way to you since it is such an old video. I've found out once rebuilding this that it still does not work. Doing exactly step by step. However, I thought perhaps it is because a tiny piece of brass, like a stopper, flew out of the inside from the reservoir. Would that tiny piece cause the mechanism not to work properly? I have seen it on the front brake, but not the clutch brake. 1996 intruder 1400. The bike sat in a garage for 23 years. Has only 1000 miles. Neither the clutch or the front brake work now that I've rebuilt them. AT first I could see a few tiny bubbles...Then working the lever dozens of times. Now nothing. Does not pump fluid. Thanks. Hope you or someone can help. Great video by the way!

[@tomscyclerecycling8242]

Hi Rick. You can contact me through my web site at www.tomscyclerecycling.com. I should be able to help you sort it out - perhaps over the phone. And thanks for the compliment!

[@MrCbell57]

@@tomscyclerecycling8242 hey I did manage to get the front brake to bleed and pressurize. But clutch side not wanting to pump up. Have taken it apart twice. Perhaps I ruptured the tiny flange on the seal. I ordered another kit. So I will retry again. Not sure why this is so difficult to make work. Any tricks to it you didn't include? Thanks

[@CarlosGarcia-ls4hn]

Can you provide me with a link as to where you purchased your pin vice? Thx

[@tomscyclerecycling8242]

It's been many years since I bought it and can't remember exactly where, but you should be able find some on Amazon. Thanks

[@Denis-bo8ms]

When everything is dissasembled, can master cylinder be blasted and powder coated? I guess I will need to remove the brake switch?

[@tomscyclerecycling8242]

It can be done, but if it has a plastic sight glass, it will also be removed. It will be destroyed in the process, so you'll have to find a replacement. I have restored dozens of these, including the powder coating and rebuilding.

[@thomaspatrickwilson]

Tom, My circlip is rusted and penetrant isnt working to free it. I have tried pushing down the plunger to relieve some pressure, but that didn't work. Any ideas?

[@tomscyclerecycling8242]

Try using a nail set (fine punch) and gently tap around the edge of the clip. Work your way around it and this might eventually break it loose. It works for me all the time.

[@thomaspatrickwilson]

Thanks! The rebuild was a success. The front lever feedback is much improved. Stopping distance, especially under heavy braking, is noticeably improved. Thanks again!

[@tomscyclerecycling8242]

Awesome Tom - glad you had good results. Now enjoy that ride!

[@kukutja]

my rubber boot tear up.. may I ask what will happened if I didnt change it

[@ShazyShaze]

+Ban De That rubber boot is to keep dirt and stuff out of the cylinder/piston assembly! I'd imagine over time dirt could get stuck in there and potentially even damage the cylinder if it gets jammed between the piston and the housing and scratches stuff up... Still, that might take kind of a long time and a lot of abuse before it happens, unless you're on a dirt bike!

[@mbkj884]

Can I just replace the seals and not the piston?

[@tomscyclerecycling8242]

You could, but the rebuild kits almost always come with a spring and piston too, so you just replace everything.

[@AlvaroGarcia-kf3ih]

1994 suzuki gsx600f katana

[@teqn0zzie]

i take my circlip out bu tthe washer and piston are still stuck

[@tomscyclerecycling8242]

Try using compressed air to blow out the piston and washer. Use a rubber tipped blow gun pressed up against the threaded hole where the brake line connects.

[@teqn0zzie]

thanks man

[@TiberiusStorm]

Or a hair from a wire brush. 3:57

[@derekpayne1950]

K

[@GreenLeafWoodwork]

Damn man nice video but you need some lotion....