I recommend you read through this completely before attempting to perform any of the listed steps… I hope this is helpful; at least it was therapeutic for me to write down.
By the way, I wrote this because of Jinkster's short write up about the mityvac and how easy it ws to use for the clutch... his post got me thinking that I needed to do mine.. so without further ado...
I found that a Mity-Vac tool (available at Harbor Freight, online at mityvac.com and on ebay, for starters) is invaluable when bleeding your clutch and I am sure I will feel the same when I use it for the brakes. I just can’t believe how using a little plastic pump took the job from an hour + about 20 minutes for a complete fluid flush.
First, what do I mean by flush? I mean replacing all the fluid in the lines, slave and cylinder. By repeatedly filling up the reservoir and using the pump to draw out the old fluid, you will not only completely replace your fluid, but you will also see exactly what sort of nastiness is hiding in your system.
First there are a few things that you have to identify…
1. two Philips head screws in the reservoir cover
2. the 8mm bleed valve on top of the clutch cylinder
At this point, I have to point out that brake fluid is nasty stuff and you don’t want to get it in your eyes, open cuts in your soda or on your fairings; I suggest you wear gloves, goggles if you are a klutz or spaz and cover any plastic and wiring with some sort of cloth or other protective layer before opening and fluid container…
Basically, you are going to remove the screws from the reservoir cover, then remove the cover, the plastic retainer plate and the diaphragm. Keep these together and put them in a place where they won’t get dirty and or fuzzy. I recommend putting them inside a ziplock bag…
Then you can use the mityvac to apply vacuum pressure to draw out the fluid. You will hook up one end of the clear tubing to the receptacle (which is already hooked up to the hand pump) and the other end to the bleeder valve. Give a few squeezes to create the vacuum and then use the 8mm open end wrench to loosen the bleeder valve. This will only take ¼ to ½ turn and you will get a steady flow.
The point of this of course is to drain the fluid, so don’t be terribly worried about bubbles, just yet. Here’s the deal though. You have to keep your eye on the reservoir; make sure nothing is getting into it and make sure it doesn’t drain completely – if it does then all you will do is suck air into the system and cause more work for yourself later.
So, as you draw fluid, keep your eye on the sight gauge; when it gets to the low level, refill the reservoir and continue to draw the fluid. You will notice that he fluid will change colors as you progress through the steps, until it al looks the color of the fluid that you are pouring into the reservoir. Now you are ready to bleed the clutch.
Close the bleeder valve and reseat your tubing to ensure a good vacuum, you don’t want to cause yourself more work by drawing air around the valve and thinking that you still have air in the line. Because the tubing may loosen up from the fluid or even from heat, depending on where you are working, you may want to hold it in place on the valve with a zip-tie.
Establish you vacuum and then again, loosen the valve ¼ to ½ turn. You will immediately see a steady flow into the receptacle.
At this point you are looking for bubbles. You will see something that looks like bubbles, but they are not – Jinkster discusses the finer points in his clutch bleeding post as fluid dynamics… I’ll just say that you will know they aren’t bubbles, because these are sort of neat looking.. the fluid is actually spreading out. Air bubble look just like bubbles; they are little round bubbles. Once you have fluid stream without bubbles, simply retighten the valve and remove the tubing.
Go back to the reservoir and refill to the top of the gauge (there are also horizontal makes on the sides of the reservoir itself). Then replace the diaphragm, plate and cover and take her off of your stand and out for a test flight.
I found that a Mity-Vac tool (available at Harbor Freight, online at mityvac.com and on ebay, for starters) is invaluable when bleeding your clutch and I am sure I will feel the same when I use it for the brakes. I just can’t believe how using a little plastic pump took the job from an hour + about 20 minutes for a complete fluid flush.
First, what do I mean by flush? I mean replacing all the fluid in the lines, slave and cylinder. By repeatedly filling up the reservoir and using the pump to draw out the old fluid, you will not only completely replace your fluid, but you will also see exactly what sort of nastiness is hiding in your system.
First there are a few things that you have to identify…
1. two Philips head screws in the reservoir cover
2. the 8mm bleed valve on top of the clutch cylinder
At this point, I have to point out that brake fluid is nasty stuff and you don’t want to get it in your eyes, open cuts in your soda or on your fairings; I suggest you wear gloves, goggles if you are a klutz or spaz and cover any plastic and wiring with some sort of cloth or other protective layer before opening and fluid container…
Basically, you are going to remove the screws from the reservoir cover, then remove the cover, the plastic retainer plate and the diaphragm. Keep these together and put them in a place where they won’t get dirty and or fuzzy. I recommend putting them inside a ziplock bag…
Then you can use the mityvac to apply vacuum pressure to draw out the fluid. You will hook up one end of the clear tubing to the receptacle (which is already hooked up to the hand pump) and the other end to the bleeder valve. Give a few squeezes to create the vacuum and then use the 8mm open end wrench to loosen the bleeder valve. This will only take ¼ to ½ turn and you will get a steady flow.
The point of this of course is to drain the fluid, so don’t be terribly worried about bubbles, just yet. Here’s the deal though. You have to keep your eye on the reservoir; make sure nothing is getting into it and make sure it doesn’t drain completely – if it does then all you will do is suck air into the system and cause more work for yourself later.
So, as you draw fluid, keep your eye on the sight gauge; when it gets to the low level, refill the reservoir and continue to draw the fluid. You will notice that he fluid will change colors as you progress through the steps, until it al looks the color of the fluid that you are pouring into the reservoir. Now you are ready to bleed the clutch.
Close the bleeder valve and reseat your tubing to ensure a good vacuum, you don’t want to cause yourself more work by drawing air around the valve and thinking that you still have air in the line. Because the tubing may loosen up from the fluid or even from heat, depending on where you are working, you may want to hold it in place on the valve with a zip-tie.
Establish you vacuum and then again, loosen the valve ¼ to ½ turn. You will immediately see a steady flow into the receptacle.
At this point you are looking for bubbles. You will see something that looks like bubbles, but they are not – Jinkster discusses the finer points in his clutch bleeding post as fluid dynamics… I’ll just say that you will know they aren’t bubbles, because these are sort of neat looking.. the fluid is actually spreading out. Air bubble look just like bubbles; they are little round bubbles. Once you have fluid stream without bubbles, simply retighten the valve and remove the tubing.
Go back to the reservoir and refill to the top of the gauge (there are also horizontal makes on the sides of the reservoir itself). Then replace the diaphragm, plate and cover and take her off of your stand and out for a test flight.
