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Running M4 brakes, manage to align the calipers and the pads perfectly. They run and feel powerful for a few rides and then tail off. When I look again at the alignment the disc is being pushed over from one side and so I have to align them again 🙁
Anyone else had the same problems....?
Something up with the system, air? leak?
Nope - you are not aligning them properly. check the vids on the hope site.
You might have a sticky piston tho but the "loosen the bolts, pull the lever,tighten the bolts" is not the best way to align calipers. Chck both pistons move - if they do set up as in the vids
http://www.hopetech.com/page.aspx?itemID=SPG139
Thanks TJ, but I should have said I've followed the guide from day one and it still does it. All pistons are moving ok.
all I can say is you need to align the pistons not just the caliper. Waht youare describing is the symptom of misaligned pistons. do it properly and you end up with the disc running centrally in the calliper and the pads both contacting the disc at the same time with the same pressure.
Yeah when I align them as the video, the pistons are even and disc doesnt flinch when the pads contact evenly from both sides.
Thats why Im so confused that after a while the pistons push unevenly and cause the drop in performance.
Thats why Im wondering what the hecks up!
Sounds like a sticky piston- wouldn't neccesarily be visible immediately, a slightly sticky one can cause unevenness over time. Obviously not a setup problem if it works fine then goes wrong.
Ok what's the solution on the sticky piston? The brakes are only a few months old.
Sticky piston - lube it. either with brake fluid or my preferred option red rubber grease - work it in and out a few times well lubed up. Hopes can dry out when on the shelf
I'd strip it, clean it and rebuild it personally with a little rubber grease but since they're so new why not warranty them?
If I could get them turned round quickly I think I would. Need the push iron for work so can't do without it for too long.
Think I'll have a go at the strip option...as long as I don't require any specialist tools 🙂
Anyone have a link to the rubber grease mentioned?
Cheers
Best place seems to be Ebay, it's inexplicably hard to buy this stuff in the shops, even really good motor factors etc don't always have it. A pot goes a loooooong way, I've got a half kilo tub which I think I bought in the 90s and is barely dented 
Use a bit of brake fluid to clean round the piston for a quick fix. I normally use silicone oil spray on mine it works a treat.
Thanks everyone. I'll try the brake fluid / silicone spray first and see how it performs.
Is it best to strip or just remove the pads and pump the lever to push the pistons out a LITTLE, then lube that way.
many motorcycle shops sell small quantities of the red rubber grease. You do need a bore cap tool to strip the calliper but you can work the pistons in and out and try to get some lube on them easily enough
Thank you TJ, I'll look into that. I do have the bore cap tool so I'll give it a go.
I had the same problem with my M4's, and now with my V2's.
If you warranty them Hope turnaround is very quick, I have sent parts on a Monday and had them back Wednesday, that was a warranty job that required a complete overhaul of front and rear V2 brakes, they have been faultless since.
Definitely something to think about, its often best to leave it to the pro's.