I bought a Shimano Deore M615 brake...

clydefrog

I bought a Shimano Deore M615 brake from ChainReactionCycles however I am a bit bothered about something. First of all it came in their own packaging but I've learnt that's because it's OEM so that explains their cheaper prices, I'm ok with that. The things that bother me are:

1. One piston doesn't seem to push all the way back flush with the caliper when the pad is pushed back against it.

2. There are a few chips in the paint on the caliper, is this normal?

3. I put a folded piece of paper between the pads and the rotor when I placed the caliper over the rotor to see what the fit was like. After pulling the lever and then taking the caliper off the rotor and removing the piece of paper, there was dirt on both sides of the paper where it had made contact with the pads that pressed against it. Is that normal?

Is this all acceptable and normal stuff or should I be bothered about it?

Thanks

Chunkers1980

1. Depends if they work ok

2. Is that acceptable to you? If not send them back.

3. What the heck?

clydefrog

Chunkers1980 wrote:

1. Depends if they work ok

2. Is that acceptable to you? If not send them back.

3. What the heck?

Well they seem to work ok if it's normal that one of them won't push right back.

Yeah that's the thing I'm the least bothered about, it won't affect anything.

The pads had dirt on them which went onto the paper that was between them and the pads when the lever was pulled... I only did it because I don't want to dirty anything myself in case I return it.

cooldad

3. Define 'dirt'.

clydefrog

cooldad wrote:

3. Define 'dirt'.

brown marks on the paper where the pads touched it.

The thing I'm most bothered about is that one piston that is out a bit, it's not even 1mm but still it can't be pushed back to be flush with the caliper and surely they should be able to.

poah

send it back and get a new one

clydefrog

I was pretty surprised the pads had dirt on them unless it's something else (they are resin pads by the way). I'd take them out and look at them properly but they are held in using one of those split pins so I'd have to bend the end of that to take it out (which I'm obviously not going to do if I'm thinking about returning it).

iLukeKendall

If the piston is protruding slightly, there's a possibility there's excess fluid in the system. Unscrewing the bleed screw on the reservoir at the lever end slightly, and catching any excess fluid that drains out seemed to allow me to fully reset my XT pistons a few months back.

cooldad

Don't mess with the fluid - it's highly unlikely to be the issue, and once you've buggered around with them you could have a problem returning them.
IMHO you're overthinking everything.
The dirt is probably pad material which will transfer to the rotor and help them bed in nicely.
But Shimano OE resin pads are rubbish anyway, so I'd be replacing them straight away anyway.

poah

cooldad wrote:

But Shimano OE resin pads are rubbish anyway, so I'd be replacing them straight away anyway.

I'll disagree with that, they do fit properly unlike some 3rd party makes

cooldad

I was talking about the material not the fit. Shimano pads are good. The OE resin ones are rubbish though.

stubs

Send it back if your not happy with the condition CRC are pretty good on returns I sent some knee pads back 2 weeks ago and got the refund 8 days later. You can do free returns just go on the website and print off a collect+ label and a returns form then take it to your nearest collect+ shop.

clydefrog

Well you mention fit and that leads me to another question. Which sintered pads should I go for that fit well to replace them, bearing in mind that I can't even push the the pads back so the plates sit against the caliper. are the superstar ones good because they're a decent price? I wouldn't want to buy new ones and find that the rotor won't even fit in between them. Also if it's not that there's too much fluid which usually seems to be the case for a piston not pushing in, what could the issue be?

stubs wrote:

Send it back if your not happy with the condition CRC are pretty good on returns I sent some knee pads back 2 weeks ago and got the refund 8 days later. You can do free returns just go on the website and print off a collect+ label and a returns form then take it to your nearest collect+ shop.

Yeah stubs I've seen that, sounds like a decent way of getting them sent back if I decide to.

poah

cooldad wrote:

I was talking about the material not the fit. Shimano pads are good. The OE resin ones are rubbish though.

My OE shimano resin pads are not rubbish.

rockmonkeysc

POAH wrote:

cooldad wrote:

I was talking about the material not the fit. Shimano pads are good. The OE resin ones are rubbish though.

My OE shimano resin pads are not rubbish.

I found them to be pretty good.

supersonic

Brakes need to bed in. Very normal for the pistons to operate slightly unevenly.

clydefrog

supersonic wrote:

Brakes need to bed in. Very normal for the pistons to operate slightly unevenly.

So would you keep it supersonic?

This is the reason I got it by the way. On my bike I have Avid Elixir 1's; on the front caliper one of the pistons had become stuck and the brake had lost power as I presume only one pad was making contact with the rotor, so I did all the usual stuff that people tell you to do (force piston out by holding the moving one and pumping the lever, clean the piston walls, lube piston walls with silicone spray etc.).

After doing all of this the stuck piston was still stuck and I also had the issue of them not being able to be pushed back. I had the same problem with the back one where they couldn't be pushed back and they were dragging on the rotor, but letting a little fluid out of the brake solved the problem on that one and it still works ok. Anyways I tried this on the front one too and I must have either loosened the screw too much or left it too long because I guess air got in and it made the brake useless.

So now after seeing how expensive the Avid pro bleed kit is (standard one is meant to be poor quality) and how much effort and time it will probably take to bleed it properly I decided to just buy a new brake instead and picked the Deore M615 (if I like it I was going to get another to replace the rear one when I have another problem with it). What I am thinking is if I return this one I would just buy the full set from somewhere (front and rear and rotors) and replace the whole brake set. But I wanted to check here first to see if I am worrying about nothing or not especially in regards to the pistons.

supersonic

If it arrived damaged, no I wouldn't. I suspect this has been used and taken off a bike, hence the brake dust on the pads.

But as for pistons, I'd give them time. Should you decide to keep it.

clydefrog

supersonic wrote:

If it arrived damaged, no I wouldn't. I suspect this has been used and taken off a bike, hence the brake dust on the pads.

But as for pistons, I'd give them time. Should you decide to keep it.

Well the only thing that could really be classed as damaged are the couple of paint chips but that is the least of my concerns and I thought that could be normal. The dirt/dust whatever it was on the pads is a bit concerning though as long as new resin pads don't naturally have a bit of loose material on them.

By the way should pads/pistons generally be able to be pushed back so far that the backplate of the pads sits flat against the caliper body, or is there usually a very small gap?

Chunkers1980

You're seriously over thinking all this. If you're happy with their condition then just get on and use them

clydefrog

Chunkers1980 wrote:

You're seriously over thinking all this. If you're happy with their condition then just get on and use them

Well I'd probably be happy enough with their condition if the pistons pushed right back. If I buy some sintered pads to replace the resin ones (which I was probably going to do) and they are bigger than the pads that are already in as many are, that could be a problem. If it is normal that the pads won't sit right against the caliper (and I don't think it is) then I wouldn't really have a problem with them.

Also is it the kind of thing where if I returned it and bought another one, would there be a good chance of getting another with the same issue?

cooldad

Nobody knows.

The Northern Monkey

Have you tried pushing the pistons back in?

clydefrog

The Northern Monkey wrote:

Have you tried pushing the pistons back in?

Yes by pushing the pads down against the pistons. Anyways I have since found this image on epic bleed solutions of the previous Deore caliper (although the inside looks basically the same as mine, same pistons etc.) showing the pistons "pushed as far back as they will go":


and mine are the same, where you can just see the edge protruding above the inside surface of the caliper. So going off this photo if that's how they should look when they are fully pushed back then mine is as it should be.

cooldad

Hallelujah