Front Hydraulic Brake help

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highdesert

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73 850 with the chrome removed long ago from the stock disk. Wonderful Magura lever and master cylinder installed years ago.

Problem: Front braking losing effectiveness.

Pads still look like they have a lot left.

Solutions? Replace pads, but with what kind? Want soft and grabby, long life not important at all to me, pads are cheap.
Remove disk, deglaze it? Rough it up with steel wool or something else?

Can hear pads constantly touching the disc on every wheel revolution. Normal?

Hydraulic fluid replaces a year ago, so still good.
Ultimate solution, pop the money for the CNW front braking solution, but like stock look.
Ideas?
 
I'd start with a bleed. Check for leeks. What kind of brake lines do you have? Old rubber lines expand and reduce braking pressure. How does the lever feel? Seals don't live forever and some fluids are harder than others on them. When I was using silicon fluid it needed to be replaced annually, it doesn't absorb moisture and can rust internals. Just my thoughts on your predicament.

Will
 
Rebuild the caliper. It could be passing a small amount of fluid causing the reduction in braking. With that nice Magura, there is a bunch more pressure than the stock MC could give. Makes sence? And at the same time, pull the disc and validate flatness.
 
Yes, the pads on disc brakes (any vehicle) lightly rub against the rotor at all times; there is no spring to retract them like there is with drum brakes. But there shouldn't be any noticeable "braking" action on the wheel. If there is, that would indicate a seized piston or some other problem. The CNW/Brembo front master cyl is worth every penny, and then some as far as improved braking performance. I gave up on the stock look, much as I would have like to retain it.
 
Thanks guys!
I do have a braided steel brake line.

Privisseriii's comment about rebuilding my master cylinder strikes particularly as I just notices a very light slime on the disc that I had to wipe off.

So, what do I do to rebuild it, what is involved, special tools?
 
highdesert said:
Thanks guys!
I do have a braided steel brake line.

Privisseriii's comment about rebuilding my master cylinder strikes particularly as I just notices a very light slime on the disc that I had to wipe off.

So, what do I do to rebuild it, what is involved, special tools?
Click to expand...

He said to rebuild the caliper, not the master cylinder. If there's anything wet at the caliper, stop riding and fix it.
 
Thanks for the good advice, swooch!

Given your experience:
So, what do I do to rebuild it, what is involved, special tools?
 
highdesert said:
Thanks guys!
I do have a braided steel brake line.

Privisseriii's comment about rebuilding my master cylinder strikes particularly as I just notices a very light slime on the disc that I had to wipe off.

So, what do I do to rebuild it, what is involved, special tools?
Click to expand...
CALIPER, HD, CALIPER.

Rebuild kits with pistons are everywhere. There are a couple of tricks with both dis and re assembly.
A pin wrench is easily made with 1" x 1/4 " steel dowels and a piece of 1/2" by 1" piece of cold roll.
Front Hydraulic Brake help

Hole are drilled .790 on center.
Remove the cap while still on the bike with the pins prodruding so that the wrench will be close to flush with the cap for best leverage.
If you were weeping fluid a little, this could be a good sign the the caliper pistons are not frozen.

Keep us posted and we'll help along the way.

Search the topics, check the manuals, piece of cake.
 
L.A.B. said:
"That's not entirely true, as the seals should act like return "springs": http://www.ucx.com/documents/squareseal.pdf"
Click to expand...

While I agree with you that in theory it SHOULD be that way and that the pads should JUST (like .001") avoid touching, my experience is that if you lift a typical disc-braked wheel clear of the ground and give it a spin, you will hear the pads lightly brushing against the rotor. THis includes brand new rebuilds with all new parts (after the brakes have been bled and are now in ready-for-use condition). You really don't want the pads to back off to any degree because that lengthens pedal/lever movement necessary to re-engage.
 
MexicoMike said:
While I agree with you that in theory it SHOULD be that way and that the pads should JUST (like .001") avoid touching, my experience is that if you lift a typical disc-braked wheel clear of the ground and give it a spin, you will hear the pads lightly brushing against the rotor.
Click to expand...

Yes I agree, as the seals only pull back the pistons, so the pads are left floating between the pistons and disc. If the seals are doing their job and retracting the pistons sufficiently, then at least, the pads should not be dragging against the disc.
 
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