[Closed] sram guide pad replacement woes

Your replacement pads are probably slightly thicker than the originals. Slacken off the bleed port screw on the lever and push the pistons all the way back, excess brake fluid will some out of the bleed port. Make sure to catch any spillage with a rag.

This ^

Can also be caused by bleeding the brakes with part-worn pads in, so the pistons set the that pad thickness

How are the guides? All avid woes sorted?

Haven't bled them yet so will go with solamanda suggestion.. Thanks for speedy replies guys

scruff - Member
How are the guides? All avid woes sorted?

Yes and no. Bleeding is easier than Elixirs, think the pistons can still corrode though, and they've definitely balls up the reach adjusters. There's a washer than wears out, and when it does the levers start self adjusting - mine are now held in place by a pile of thread lock

@solamanda . If I loosen the bleeds crew and push calipers back will I then have to bleed the brakes?

No, not as long as you don't let the caliper suck in air

As suggested previously, loosen the lever's bleed screw, not the caliper, as it's at the systems highest point, so if any air gets in, it stays in the reservoir, and is a simple job to remove.

OK. . Did as instructed but unfortunately it's not much different. I think it may be a sticky piston. When pads are out and I have a block in place and push the lever I have a good feeling lever and it returns.. take the block out and put the wheel back on and press the brake- brake works then lever doesn't return and pads drag..

Sorry - I was going to reply earlier, but got tied up. The suggestion above was unlikely to work, unless the new pads are bigger than the old pads were originally, but you've found that out!

Here's what you need to do.

Wheel out, put one of your old brake pads back in, then use a large flat bladed screwdriver to hold this in place - then twist the screwdriver so that it also holds one of the pistons on the other side in place.

Be careful - the pistons are fairly brittle, so just enough pressure to stop it moving.

Then squeeze the lever gently - you need to move the free piston out a little, just enough to expose about 1mm of 'clean piston' - you'll see clearly when it is exposed. Be careful again - you don't want to squeeze too much or the piston will pop out completely.

Once the dirty bit of the piston is fully exposed it needs cleaning - I just spray hard with brake cleaner from an aerosol and clean with a Qtip (cotton bud)

Then lube the piston with a little brake fluid (don't use grease unless you're certain you have the right type - some greases will contaminate the fluid and harm the seal.

Then push the clean and lubed piston home carefully with the screwdriver blade - keep the pressure square as you do this, if the piston twists it won't go in fully.

Now repeat on the other three pistons.

Reading this back it sounds like hard work - but be careful and methodical and it really isn't, will only take 15 mins.

They're great brakes, so well worth getting them working smoothly.

Phil

Thanks Phil, apreciate the lengthy reply. I'll do this this afternoon.. as I said I definitely thinks it's a sticky piston.. never knew how to clean them though.. cheers!

I wouldn't be touching bleed screw.

Have you got a model with bite adjuster (note, bite adjust is different to the reach adjust for the lever)? If so, adjust that so the pistons back out fully. Also push back the pistons with a spreader or flat bladded screwdriver using old pads in. Just lever carefully each side until enough to get the wheel in with new pads. Usually are a bit close bite at first.

Remember the Guide are 4 pistons so you need to be careful they are pushed back in equal measures else you'll get uneven wear on the pads.

And yeah, cleaning it all up can be a help.

Another is if it's dragging it could be simply calliper alignment is off. With pistons fully pushed back, loosen calliper bolts slightly, apply and hold brake, re-tighten. Possibly using bits of thin card between pad and disc.