Brake, Clutch fluid service

One might wonder if it's necessary to change all the fluid in the systems. It would seem that all one needs to do is remove the fluid in the master cylinder reservoir and replace it with new dry fluid. This would lower the moisture content of all the fluid in the system.

The remaining moisture would disperse throughout all the fluid and the boiling point would be high again. No opportunity to introduce air into the system.

Well, I wouldn't wonder!

Why do a half-assed job? If you are going in, replace it all. No brainer to me.

Naaaaaaah. For as easy as it is, why not just do the job correctly?

Well, for starters, any water or sediment will accumulate at the lowest point

in the system. So it makes sense to freshen-up the fluid in the calipers.

It's really easy to change ALL the fluid in front, rear and clutch hydraulic systems. Motion Pro makes a great tool (Mini Bleeder) that acts like a speed bleeder but is not installed on the bike. I reviewed the tool for MCN and it works great.

Here is the link to Motion Pro's website Mini Bleeder

Here is a You Tube link to the

Constant Mesh said:

One might wonder if it's necessary to change all the fluid in the systems. It would seem that all one needs to do is remove the fluid in the master cylinder reservoir and replace it with new dry fluid. This would lower the moisture content of all the fluid in the system.

The remaining moisture would disperse throughout all the fluid and the boiling point would be high again. No opportunity to introduce air into the system.

Click to expand...

That would be the first half of the job. After you empty, clean, and refill (before pumping) the master, then just pump the old fluid out of the bleeder until you see clean fluid and your done. Just don't let the master get empty while bleeding, and don't pump the master while it's empty.

3dogs said:

It's really easy to change ALL the fluid in front, rear and clutch hydraulic systems. Motion Pro makes a great tool (Mini Bleeder) that acts like a speed bleeder but is not installed on the bike. I reviewed the tool for MCN and it works great.

Here is the link to Motion Pro's website Mini Bleeder

Here is a You Tube link to the

Click to expand...

I just checked my 08 and the brake bleeders are 10mm and the clutch is 8mm? Can I replace my brake bleeders with 8mm to accomodate the mini bleeder as mentioned above? I'm wondering about the different volume the 10mm bleeders allow? Did that make sense?

Constant Mesh said:

One might wonder if it's necessary to change all the fluid in the systems. It would seem that all one needs to do is remove the fluid in the master cylinder reservoir and replace it with new dry fluid. This would lower the moisture content of all the fluid in the system.

The remaining moisture would disperse throughout all the fluid and the boiling point would be high again. No opportunity to introduce air into the system.

Click to expand...

The assumption bolded from your post is wrong because moisture and other contaminates will not diffuse through the brake tubing and ABS system. The problem with contaminated old fluids is that the boiling point is lowered. We really aren't concerned with the master cylinder as it is not exposed to heat, it is the fluid you're not changing near the brake calipers, or in the lines near hot engine parts and near the hot brake calipers that will boil first. You must flush to get good fluid to the location where the old fluid will fail.

This is an incredibly easy job; why short-change it? I use a vacuum bleeder, but even pumping fluid through the old fashioned way, would take less than an half hour to do both front rotors, the rear brake and the clutch (don't forget the linked bleeder on Gen II).