Shimano Deore M615 disc brake set up help !!

stantheman206

I have recently treated myself to these brakes replacing my old Hayes El camino disc brakes.
I am having real trouble setting the front brake, the rear is perfect just the right amount of clearance, the front however is a different story. The caliper sits right on the disc and has real rubbing issues, it's a constant tick tick sound as the holes in the rotor go through the pads??? I have re set the pistons and re set the caliper positioning by slacking off the bolts, pulling the lever and then re tightening the bolts, no luck.

I have heard that bleeding some of the fluid may help but i'm no expert so what do people think. I would add that I will have to shorten the hoses as both a way too long so i'll have to re bleed them at some point any way.

Any advice would be appreciated.

Ps I have kept my old rotors (i think they are hayes) if this make any difference

cobba

Inner pad rubbing?
Outer pad rubbing?
Both pads rubbing?
Constant rub or intermittent rub?
Rotor true?

jimothy78

stantheman206 wrote:

I have re set the pistons and re set the caliper positioning by slacking off the bolts, pulling the lever and then re tightening the bolts, no luck.

I've seen this technique recommended, but found that it's not very reliable - just get yourself into a position where you can see through the gaps between the rotor and pads and allign it by eye - allign at one bolt/end of the pad, tighten just enough to hold it (but still allow you to move the calliper at the other end), and then allign the other one independantly. When the gap is right at both ends, then gradually tighten both bolts to working tightness, checking the calliper doesn't move when you're doing it.

Also, make sure that the wheel's qr is fully tight when alligning, otherwise the spacing may change when you tighten it later.

.blitz

As above it's best to visually centre the caliper over the disc. With the mounting bolts loose, gently pump the lever and bring the pads closer to the disc. One pad might contact the disc before the other. If this happens hold the disc against the pad that is already in contact with the disc to allow the other one to move. When both pads are in contact with the disc at the same time and retracting by an equal amount, tighten the mounting bolts. The disc should not flex when the brake is applied

stantheman206

cobba wrote:

Inner pad rubbing?
Outer pad rubbing?
Both pads rubbing?
Constant rub or intermittent rub?
Rotor true?

There is constant rubbing on the rotor, the rotor is true and it looks as though all the pad is rubbing.

Jimothy - there is no space between the disc and the rotor to align the caliper! the pistons are hitting the disc at the same time. I only have the bleed option left when I have to shorten the hoses, if that doesn't work I stump!!!!

Could it be my rotor some how. It's 5 years old but it's true. To be honest I had this exact same problem with the front end just before got rid of my old hayes brakes

cooldad

stantheman206 wrote:

To be honest I had this exact same problem with the front end just before got rid of my old hayes brakes

So unlikely to be the new brakes causing whatever.

jimothy78

stantheman206 wrote:

Jimothy - there is no space between the disc and the rotor to align the caliper! the pistons are hitting the disc at the same time. I only have the bleed option left when I have to shorten the hoses, if that doesn't work I stump!!!!

So both pads are rubbing all the time? Sounds like the pistons have been advanced by someone pulling the lever with nothing in between the pads.

You should be able to push the pistons back without having to, but if you intend to shorten the hoses and bleed the system anyway, then you can connect a bleed tube to the bleed nipple (to stop any overflow spilling all over the brakes), loosen the nipple by 1/4 of a turn and that should allow you to push back the pistons fully without any resistance. Then fit the pad spacer and shorten/bleed with the pistons held in the right position.

The Rookie

No space between disc and rotor......not a surprise - same part.

Pads should touch the discs not the pistons......

Does sound like the disc is either warped or dished.

stantheman206

The Rookie wrote:

No space between disc and rotor......not a surprise - same part.

Pads should touch the discs not the pistons......

Does sound like the disc is either warped or dished.

To clarify, I meant no space between rotor and pads. And the pads hit the rotor at the same time. Does dished mean that the rotor is curved in or out on the circumference. It may be that as when I put the red travel spacer between the pads it is loose and there is some movement suggesting the rotor is the issue??

The Rookie

Yes dished means the out braking rim is not in the same plane as the centre mounting section, this means the braking surface will sit at an angle to the pads and more likely to rub.

stantheman206

As i've got to shorten the hoses anyway i'll bleed the brakes after and see then if the problem is still there. If it is i'll look at replacing the rotor

The Rookie

Just take it off and put it on the kitchen worktop.....easy to check!

photonic69

No need to take it off. Just place a metal straight edge across it. Easy to spot if it is dished. Saves time too ;-)

stantheman206

OK, so i've finally got round to shortening both hoses, really easy and I surprised myself a bit. To my amazement the rear didn't need re bleeding so I've left that for now so it was just the problematic front end to sort.

I can now report that the same feckin problem remains, even after a good bleed the front pads are still rubbing the rotor constantly. This is what i've tried;

The rotor is not warped or dished
I tried bleeding a little mineral oil out to see if this makes any difference, Nope!!
I have aligned the pads by eye and also by loosening the calliper bolts and pulling the lever, neither have worked!
I have tried going easy on the QR skewer and then really gone to town on tightening the f/wheel, neither have worked!
I've checked the (brand new pads)for contamination and given the rotor really good clean with disc cleaner,not worked!

This is driving me mad so any more suggestions people
Thanks,
a disheartened (and p***ed off) Andrew

cooldad

Ride it and let everything bed in.

jimothy78

The only other thing i can think is that the calliper isn't sitting straight to the rotor - maybe the mounting tabs/post on the fork or the adapter itself isn't quite straight. I had this problem once where the paint on the frame's tabs bulged towards the outside, and caused the calliper to sit at a slight angle. If this is the case, however, then you should be able to see that the pads aren't perfectly parallel to the rotor faces - maybe one is rubbing at the top/outside and the other at the bottom/inside?

If this is the problem, then depending on how extreme the it is, then it may well auto-correct as the pads bed in to match the angle of the rotor. In my case, I simply carefully removed the paint on the tabs, and the metal itself was dead straight.

photonic69

Is there a return spring between the pads? Is it fitted? Is it in good order?

Perhaps try the rear pads/spring in the front? Perhaps try rear rotor on front if same size?
Can you push back pistons in either side of caliper quite smoothly? Usually if you push one side the other comes out so wedge it somehow. They should be fairly smooth to allow for clearance.

Apart from that I'm outta ideas. Good luck!

holiver

stantheman206 wrote:

OK, so i've finally got round to shortening both hoses, really easy and I surprised myself a bit.

I can empathise with your brake problems, sometimes there are a right pain to sort out! Just to check you pushed the pistons in as far as possible when you bled the front brake?

I am considering these brakes to replace the mechanical ones on my P1. The hose length from CRC is pretty lengthy so I would need to chop them down. Might you be able to describe the process you took or link the one you followed?

Thanks

YateleyChap

holiver wrote:

stantheman206 wrote:

OK, so i've finally got round to shortening both hoses, really easy and I surprised myself a bit.

I can empathise with your brake problems, sometimes there are a right pain to sort out! Just to check you pushed the pistons in as far as possible when you bled the front brake?

I am considering these brakes to replace the mechanical ones on my P1. The hose length from CRC is pretty lengthy so I would need to chop them down. Might you be able to describe the process you took or link the one you followed?

Thanks

http://www.epicbleedsolutions.com/blog/ ... -bleeding/

I also recommend their Shimano bleed kit. Cheap, really easy to use and fairly fool-proof for noobs like me.

holiver

Sweet! Thanks chap.