[badphish]

OK, so I 'm finally switching from 6" to 8" rotors. Put the new rotor on the rear and the appropriate brake adapter for the caliper. The pads were so tight the wheel wouldn't spin freely. No problem. Removed the wheel. Replaced the current pads for old pads and used a screwdriver to push the pistons in. Put the good pads back in and the wheel back on, flipped the bike upright and started to re-center the caliper. I noticed the lever was a little spongy and when I looked down there was some brake fluid on the floor where the lever was. I looked at the lever and sure enough it was wet with fluid. I couldn't tell where it was coming from, so I wiped it down with alcohol pads and pulled the lever hard several times to see if any more would come out. Nothing. So, now that I've written a novel my question is, do I need to rebuild the master cylinder or will I be safe just rebleeding the system? I'd really like to just bleed it once, since they are a biatch.

thanks

 

[Racebike]

I have a feeling the small plastic plug where you put the bleed insert has popped out when you were pushing the pads back in their bores.

Look if the plug is missing or sticking out.

Edit: spelling.

 

[badphish]

Not sure if that was the case or not. It definitely didn't come completely out. It may have come out enough to leak fluid. I bled the system yesterday to see if it was just a fluke thing or what. I was pretty much done and just needed to push the pistons in just a wee little bit, and this time the damn plug shot across the garage.

 

[Racebike]

The rubber baffle in the reservoir can flex a bit under pressure and allow a bit of extra oil but the little plug can't take that much. The plug or its seat (the lid/baffle combo) may be damaged, be aware of this.

You will need to reset the pistons before you bleed the system, otherwise you risk having too much oil in there.

 

[cracked]

if I can chime in here:

I have a set of 2 y/o HFX's. Everytime I use them they seem to get squishier.
I had them bled on Saturday. Changed my brake pads, bedded them in and then rode DH on Sunday. About an hour in they got wicked soft and I lost a lot of modulation.

DO I need a new master cylinder? or would it behoove me to invest in some braided line? OR?????????????

Thx guys!

 

[zebrahum]

if I can chime in here:

I have a set of 2 y/o HFX's. Everytime I use them they seem to get squishier.
I had them bled on Saturday. Changed my brake pads, bedded them in and then rode DH on Sunday. About an hour in they got wicked soft and I lost a lot of modulation.

DO I need a new master cylinder? or would it behoove me to invest in some braided line? OR?????????????

Thx guys!

Sounds like the bleed may have left some air in the system. I would have them re-bled. Failing that, it's a long, expensive, and tiresome journey to figure out which piece of the puzzle is actually causing you problems. It could be the line, the master cylinder, or some residue on your rotors. Unless you have a pile of parts to change back and forth, it may not be worth fully pursuing.

Try rebleeding, and see if you can get your shop to diagnose the problem. Try to get a price quote if you tell them you're not sure if it's the MC or the line, and how much to figure out which is the problem.