.png "Powered by vBulletin")
So I wanted to reuse my master cylinder on my GS1150E but the sight window was clowdy and cracking. There is not much out there about how to restore them so I posted this guide for you as I discovered how to go about doing this.
Here are the steps to make a master cylinder look just like new for about $32, much better then the almost $200 for a new one.
Read all the instructions before you begin.
You will need:
Tools (plus special snap ring pliers)
Mineral Crystal
Jewlers Epoxy
Epoxy based paint
Cleaning supplies
Sand blaster or stripper
1. Drain and disassemble the Master Cylinder. You will need a very narrow and long snap ring pliers to release the piston.
2. Soak the parts in a cleaner, I used simple green. Then scrub, rinse and dry.
3. Sand blast off all the old paint. It's probably coming off some anyway. I used my personal sand blaster but you could use other means of getting the paint off if you prefer. Dry with compressed air to ensure all junk is out of the holes and you have not clogged the fluid paths.
4. Remove the old sight glass by carefully drilling a small hole in the center, screw in a screw and slide hammer it out. It only takes 1 good yank. Carefully clean up the residue with a combination of jewlers screwdrivers and a scribe. Dont gouge the aluminum. Be careful and take your time.
5. Measure the opening as accurately as possible. Mine was just under 17mm x 1mm thick.
6. Order a 17mm mineral crystal ($2) and jewlers epoxy ($5) online. These are used for watches and are not effected by the brake fluid. I had to fine sand the edges of my crystal to get the final fit. DONT FORCE IT. You will get it stuck. It should be able to drop in and out.
7. Use painters tape and tape one side of the glass, trim the excess with a razor blade. Then remove all fingerprints from the other side.
8. Mix the epoxy. Carefully apply a bead with a toothpick around the ring seat of the master cylinder. Make sure it is a complete ring of epoxy or you will have a leak. DONT USE TOO MUCH. It will get on the middle of the glass and look bad. Work quickly as the epoxy dries fast. Practice your technique on something else before you work on your cylinder. "I cant stress enough the importance of this step. You have to do this correctly. I did mine in the kitchen because the lighting was the best and I wore magnification glasses to be sure I could see and did not mess this up."
9. Drop the crystal in the ring, tape side out. Press in lightly to ensure all the edges seal. Dont remove the tape until after painting the cylinder.
10. Let dry over night.
11. Paint your cylinder with an epoxy based paint. Epoxy paint is resistant to the brake fluid. DONT PAINT THE PISTON HOLE OR INSIDE OF THE CYLINDER. Only paint the original painted areas. Follow the instructions on the can. This is important.
12. Let dry over night.
13. Taka a chopstick or wooden dowel, cut the end flat like a screwdriver, then gently scrap the tape off the mineral crystal. Touch up any paint chips as needed.
14. Rebuild the cylinder using a rebuild kit ($25). Make sure you get the components in the right order. I replaced my cylinder cap screws with stainless.
15. Install on bike, bleed the brakes, enjoy you awesome restoration.
You're welcome
David Borges
85' GS1150E
Here are the steps to make a master cylinder look just like new for about $32, much better then the almost $200 for a new one.
Read all the instructions before you begin.
You will need:
Tools (plus special snap ring pliers)
Mineral Crystal
Jewlers Epoxy
Epoxy based paint
Cleaning supplies
Sand blaster or stripper
1. Drain and disassemble the Master Cylinder. You will need a very narrow and long snap ring pliers to release the piston.
2. Soak the parts in a cleaner, I used simple green. Then scrub, rinse and dry.
3. Sand blast off all the old paint. It's probably coming off some anyway. I used my personal sand blaster but you could use other means of getting the paint off if you prefer. Dry with compressed air to ensure all junk is out of the holes and you have not clogged the fluid paths.
4. Remove the old sight glass by carefully drilling a small hole in the center, screw in a screw and slide hammer it out. It only takes 1 good yank. Carefully clean up the residue with a combination of jewlers screwdrivers and a scribe. Dont gouge the aluminum. Be careful and take your time.
5. Measure the opening as accurately as possible. Mine was just under 17mm x 1mm thick.
6. Order a 17mm mineral crystal ($2) and jewlers epoxy ($5) online. These are used for watches and are not effected by the brake fluid. I had to fine sand the edges of my crystal to get the final fit. DONT FORCE IT. You will get it stuck. It should be able to drop in and out.
7. Use painters tape and tape one side of the glass, trim the excess with a razor blade. Then remove all fingerprints from the other side.
8. Mix the epoxy. Carefully apply a bead with a toothpick around the ring seat of the master cylinder. Make sure it is a complete ring of epoxy or you will have a leak. DONT USE TOO MUCH. It will get on the middle of the glass and look bad. Work quickly as the epoxy dries fast. Practice your technique on something else before you work on your cylinder. "I cant stress enough the importance of this step. You have to do this correctly. I did mine in the kitchen because the lighting was the best and I wore magnification glasses to be sure I could see and did not mess this up."
9. Drop the crystal in the ring, tape side out. Press in lightly to ensure all the edges seal. Dont remove the tape until after painting the cylinder.
10. Let dry over night.
11. Paint your cylinder with an epoxy based paint. Epoxy paint is resistant to the brake fluid. DONT PAINT THE PISTON HOLE OR INSIDE OF THE CYLINDER. Only paint the original painted areas. Follow the instructions on the can. This is important.
12. Let dry over night.
13. Taka a chopstick or wooden dowel, cut the end flat like a screwdriver, then gently scrap the tape off the mineral crystal. Touch up any paint chips as needed.
14. Rebuild the cylinder using a rebuild kit ($25). Make sure you get the components in the right order. I replaced my cylinder cap screws with stainless.
15. Install on bike, bleed the brakes, enjoy you awesome restoration.
You're welcome
David Borges
85' GS1150E