Ducati.org forum banner
1 - 20 of 25 Posts

·
Registered
Joined
·
2,127 Posts
Bleeding the master is the same as the slave. You pump the lever three times, hold it, open the bleed port then close the bleed port. Do the same thing a few times until you get feeling in the lever. A lot of people back bleed the slave cylinder to the master. I generally fill up the master, suck it through the slave nipple. Then I pull the slave cylinder away from the engine a few mm by loosening up the screws a little bit. Pump the master cylinder which pushes out the slave cylinder piston. Then when you push on the slave cylinder, it back-bleeds the system up to the master. Do that a few times and you will literally push-out all the air bubbles.

I don't like pushing oil into the system because there is an even greater chance of air getting into the system because it's nearly impossible to make a perfect seal. There are speed bleeder nipples which do work better, but that's a whole other can of worms.

That back bleeding trick I posted above is commonly used in the industry.
 

·
Registered
Joined
·
77 Posts
Discussion Starter · #6 ·
im in canada so i think your harbour freight is equal to our princess auto and i was going to get this which look to be the same as you're suggesting. Vacuum Pump and Brake Bleeder Kit | Princess Auto

Not gonna lie, i spent the last hour googling and watching the youtube vids and it looks a little intimidating. The guy did say it was easy and if i couldnt do it i dont deserve the duc lol
 

·
Registered
Joined
·
1,181 Posts
Very similar to the Mighty Vac I use. Not necessary but it speeds up the bleeding process a ton. Instead of opening and closing the nipple and re-squeezing the lever you just open it once and maintain the vacuum until the reservoir needs refilling.
 

·
Registered
Joined
·
1,230 Posts
Any dot 4 brake fluid will do right?
You can go with universal DOT 4 brake fluid if you like ..

Might wanna try something more performance orientated like Motul or Amsoil.

Extreme pressure and heat can push conventional brake fluid beyond its boiling point.
 

·
Registered
Joined
·
2,389 Posts
Bleeding the master is the same as the slave. You pump the lever three times, hold it, open the bleed port then close the bleed port. Do the same thing a few times until you get feeling in the lever. A lot of people back bleed the slave cylinder to the master. I generally fill up the master, suck it through the slave nipple. Then I pull the master cylinder away from the engine a few mm by loosening up the screws a little bit. Pump the master cylinder which pushes out the slave cylinder piston. Then when you push on the slave cylinder, it back-bleeds the system up to the master. Do that a few times and you will literally push-out all the air bubbles.

I don't like pushing oil into the system because there is an even greater chance of air getting into the system because it's nearly impossible to make a perfect seal. There are speed bleeder nipples which do work better, but that's a whole other can of worms.

That back bleeding trick I posted above is commonly used in the industry.
How do you pull the master cylinder away from the engine? Do you mean the slave?
 

·
Registered
Joined
·
303 Posts
I have owned a MityVac and a compressor vac as well. Truly I dont see why you need either one on a motorcycle when you can access both the bleeder valve and the lever (front) or pedal (rear) all on your own (just my $0.02. If you have them already for your cars, ok sure use it then, but I dont even bother breaking mine out). Just follow the instructions above, use some clear tubing and a catch can (old plastic coke bottle or some crap (I do this and drilled a hole in the lid so the clear tube is tight, and so i can see how much is in there, and the color). EZ.
 

·
Registered
Joined
·
77 Posts
Discussion Starter · #16 ·
I have owned a MityVac and a compressor vac as well. Truly I dont see why you need either one on a motorcycle when you can access both the bleeder valve and the lever (front) or pedal (rear) all on your own (just my $0.02. If you have them already for your cars, ok sure use it then, but I dont even bother breaking mine out). Just follow the instructions above, use some clear tubing and a catch can (old plastic coke bottle or some crap (I do this and drilled a hole in the lid so the clear tube is tight, and so i can see how much is in there, and the color). EZ.
Care to elaborate? id rather not buy a tool unless i absolutely needed it. Correct me if im wrong but would i hook up the clear tube to the nipple than basically use the clutch lever as the pump to get the old fluid out?
 

·
Registered
Joined
·
303 Posts
Care to elaborate? id rather not buy a tool unless i absolutely needed it. Correct me if im wrong but would i hook up the clear tube to the nipple than basically use the clutch lever as the pump to get the old fluid out?
I know my reasoning sounds stupid, but I feel I have to clean the MityVac thoroughly when I am done, but I dont feel I have to clean a crappy coke plastic bottle and clear tube. So lazyness gets me. Yes, the hose to the nipple, its tight in the lid of my coke bottle, It just hangs there about 12" below the lever, I squeeze the lever and slowly open the bleeder valve, then before you bottom the lever, tighten the bleeder, repeat. Follow the order listed above and It's easy enough. Just ensure that you never let the fluid level get too low in the reservoir obviously you'd suck air in and be back to square 1. If it means you have to go spend $30 on a pump, i'd skip it.

Now on a car when you need someone to push the brake pedal and someone to operate the bleeder, the vac is really needed.

Once again just my $0.02.
 
1 - 20 of 25 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top