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Discussion Starter #1
Completed front brake caliper upgrade and I think it doesn't hurt to give some advice to those, who might swap the caliper too!

Messing around with the toxic and highly aggressive brake fluid (glycol) isn't everybody's favorite hobby, but we can avoid that easily, if we do it right!

Here we go:

1.) Unscrew the ABS sensor and the brake line duct, unclip the ABS sensor cable from the brake line and store it out of the way.
2.) Unbolt the original caliper, press the brake pads back as far as possible.
3.) Pull the brake lever all the way to the bar and fix it in this position. This will prevent draining the brake fluid reservoir, when we disconnect the brake line.
4.) Put a suitable transparent plastic tube (0.5m) onto the bleeding valve of the caliper and hang it into a clean bin. You will need that tube for bleeding at the end as well! Open the valve.
5.) Unscrew the upper brake line fitting slightly, untill the brake fluid starts draining into the bin. This will suck air into the brake line and prevent messing brake fluid onto coloured surfaces of the bike. As soon as te brake fluids stops flowing, disconnect the upper brake line fitting.
6.) Keep the bleeding tube, throw the caliper into your waste bin and spit on it!

Take a break and celebrate the elimination of the crap with a cold beer!

7.) Install the new caliper and tighten all bolts as specified.
8.) Install the new brake line and tighten the fittings as specified. Use new seal rings!
9.) Reinstall the ABS sensor with cable and duct.
9.) Release the brake lever.
10.) Put the plastic tube onto the bleeding valve and hang it into the clean bin with the drained brake fluid. Bleed the air out of the system carefully, frequently pulling the lever with slightly open valve and releasing it with closed valve. Refill the brake fluid reservoir as soon as the level drops to minimum. Attention: If you proceed with open reservoir, release the lever allways very slowly, otherwise the brake fluid will shoot up to your ceiling or into your eyes! Continue bleeding carefully until no more air bubbles are present neither in right nor in left end position of the bar!

Gratulations: You are done! Time to celebrate the upgrade with another beer!

Werner Wernersen>:)
 

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Discussion Starter #5
Sorry, I forgot to state 2 important remarks:

1.) If you couldn't hold back to mess around with the brake fluid despite of my ingenious installation tricks (see above), rinse every contaminated surface with lots of water immediately (Dot4 brake fluid is based on glycol, which is highly water-soluble)!

2.) You may add any Dot4 brake fluid (based on glycol), when you bleed the system. But do not contaminate your system with Dot5 brake fluid (based on silicon)! This would build up flakes and choke your brake system!
 

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So... what are your first impressions of the brake upgrade? Did it meet your expectations?
 

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Discussion Starter #7
Installation and draining completed with absolutely no troubles following the process I adviced above.
The kit is beautifully machined and fits perfectly.
The classic Bobber look didn´t change anyway, which was the second important thing for me (First was getting an acceptable braking performance)!
The clearance to the spokes is more than 5mm and thereby absolutely sufficient.
Applying the same hand forces at the brake lever it´s movement is about 40% larger after the upgrade, as expected due to the now appropriate hydraulic ratio (total caliper piston area / master cylinder piston area = 11.8)


As soon as the weather conditions allow, I will do the road tests and try some two finger Bobber stoppies!


Stay tuned!


Werner Wernersen>:)
 
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