Fresh Hydraulics.... Fluid Anyway

[txbanditrydr]

Just finished up putting fresh fluids in the hydraulics... front & rear brake systems and clutch.  The bike is a little over two years old so it was definitely time.  I did the clutch after four months or so - for some reason it got very dirty that quick.  It was just as dirty this time too.  Can anyone offer up a clue as to why???

The job took about four hours including the trip to get brake fluid and final clean-up.  I also cleaned the brake caliper/pads/rotors while there.  The Mity-Vac worked perfectly... I was able to borrow the deluxe model with the vacuum gauge.  

The biggest pain was taping plastic sheeting to protect the paint/plastic from brake fluid.  I spilled a drop on my lift table and it instantly left a mark so you'll want to do a stellar job protecting the bike.  Use plenty of rags or paper towels under each reservoir too - it's dang near impossible to avoid spilling a little.

The reservoirs and lines were flushed... kept adding fluid until it ran clear into the Mity-Vac.  Two 12-ounce bottles would have been plenty... I bought a 32-ounce bottle which would be great for doing two bikes.  Still - it was only six bucks.

After tightening the bleeder screws I twisted a paper towel and stuck it in the bleeder hole to soak up any extra fluid.  There's quite a bit there that will "appear" to be leaking out but really is just seeping around the threads - the system itself was good and tight.  Wrapping a paper towel around the threads and shooting a little compressed air into the bleeder hole got all the extra fluid out - then just wipe with a rag soaked in brake cleaner fluid.

Things I'll do different next time.... 1) Don't push the pads/pistons all the way back - you end up adding a lot of fluid after putting things back together.  2) Pull the bleeder fittings and wrap them with Teflon tape to provide better vacuum with fewer air bubbles.  Next time will likely be when I add stainless braided lines this winter.

Took the bike for a spin and everything is working great - plus no leaks!!

[Blade]

Nice write up. I would also recommend wire tying the handles back over night to help get any remaining air bubbles out of the systems. I also use a 5lb weight on the rear brake lever to help there too.

[txbanditrydr]

Thanks, Blade... you were part of my success.

I was careful to avoid pulling the reservoir levels below the drain hole - that should keep air from entering the system.  Still, putting things under pressure is an excellent part of being 100% correct.  You don't want any problems with stopping your mo'sheen!!  

[elbandito]

I found the best way to bleed my brakes was my 4 (well almost 5) year old.  He absolutely loves my bike and was a big helper.  I'm not sure how well he'll do with the front brakes, but the rear brakes were perfect -- he just pressed down (with his hands) on the brake lever while I let the fluid out.  

[jeffw]

When you used the MityVac, did the bleeder screws leak?  I tried to use mine when I did the same thing, and the screw leaked around the threads the entire time.

[txbanditrydr]

Yup.... lots of air bubbles.  See my item #2 in the O/P concerning things I would do different.

[GETFURIOUS]

TWO THINGS.....

1) I USED THE MIGHTY VAC AND I HATED IT.....I COULD NOT GET IT TO HOLD PRESSURE WITHOUT LEAKING AIR INTO THE SYSTEM.....

SO I JUST BLED THEM THE OLD FASHIONED WAY.....

2) WHAT TYPE AND BRAND OF BRAKE FLUID DID YOU USE?....(REGULAR OR SYNTHETIC, DOT 4 OR DOT 5, ETC.).....

THANKS.....

[H2RICK]

Can anyone offer up a clue as to why???

WAG, but you probably use the clutch about 10 times as often as you use the brakes.....so......more action, more heat, more chances for moisture to get past the seals in the master cylinder, heat from the engine "soaking" the slave cylinder, etc etc blah blah blah.