RubeRad

Trying to assemble a BD with Avid Elixir 7 hydraulic brakes, not familiar with even mech disc brakes at all, please help!

With difficulty I managed to extract the plastic spacer from between the front pads, and the spacing is now too tight to accept the rotor. Based on a few utubs, I tried spreading them by prying with a screwdriver and with a butter knife, I jammed the spacer back in there and tried to wiggle them open wider, but no joy.

The back brake pads have plenty of clearance for the rotor, I'm not sure what is different with those vs the front.

I've looked through the manual, and it seems to imply (p30) the usual kind of procedure to push back the pistons, but I'm not having any success.

Is there a screw or adjustment that will release some pressure from the system to allow the pads to spread? As far as I can tell, the screw at the lever is just a reach adjustment, and on the caliper I see only mounting bolts, the clip to retain the pads, and the bleed screw. If I open the bleed screw, will some fluid come out (and would that be better or worse?)

RubeRad

Found some other posts that did suggest opening the bleed screw to let out some fluid, I tried it and just a few drops out allowed the provided pad spacer/spreader to push those pads/pistons back.

Hopefully once I get the wheel in the pads will be able to retract on their own with regular braking...

hueyhoolihan

^^^ good advice.

just a 'lil dab will do ya.

JanMM

Have heard that can happen. Only experience is with mechanical Avids.

cale

Releasing some fluid is the same as lengthening the cable so as long as you didn't introduce air into the system you should get the results you want. The system is designed to "suck" the pistons back into the calipers. Ever so slightly.

wschruba

This is a common misconception with most hydraulic systems on the market right now, but worth touching on. An 'open' system (without an adjustable reservoir) uses the reflex action of the square-edge seal around the piston to pull it back. As the pads wear, the piston is allowed to travel further than the reflex action of the seal, effectively self adjusting.

In this particular case, letting a small amount of fluid out of the system is the right thing to do, but it can also be indicative of other problems.

RubeRad

Finally got it together for a test ride. Braking is great!

cale

I did considerable research last week when installing Avid Elixir 3 brakes and I came across several reputable sources that suggested that bleeding a small amount of fluid on first installation was advisable (even necessary) in addition to advise regarding "exercising" the pistons within the calipers, etc. So, I don't think the OP should take any negative feedback from his /her experience.

fietsbob

taking the pads out and prying the pistons apart , should push the fluid up into the expansion tank in the master cylinder,

Its what I did when i replaced the Pads on the front discs of my car.. just a bigger screwdriver..

expansion tank is there to let hot fluid expand, somewhere.

never touch the brake lever when the wheel is out .. the automatic pad wear adjuster wants to fill in the Gap.

wschruba

No negative feedback intended...

The OP said he/she is new to hydraulic brakes, so I replied with information that was relevant to what you posted. Any one who owns hydraulic brakes long enough will deal with sticking piston seals, which just so happens to also coincide with the same symptoms.

At the risk of sounding like a broken record, he did the right thing in this case.

Over-filled Elixirs were not uncommon from the factory.

RubeRad

(I'm a he fyi, in my avatar that's me on the bike and my wife on the wheel in a tourist shot from a group ride down the Haleakala volcano in maui)

Totally new to discs, esp hydros. Reading online I did see also about sticking pistons, I was scared that might be the problem. This is a BikeIsland bike, they told me it is 2013, so presumably it was on BD back then and the last few never sold. So it's been sitting around for a few years, I would believe that unused calipers could get sticky like that.

Fortunately though just that little bleed, everything is OK for now, rode around the complex last night to bed in with recommended procedure (20x medium->slo and 20x fast->slo), rode it to work today, no issues. I think I'm in the clear!

rsilvers

I did verify that DeSlackinators work on Code-R, so that solves the slack issue:

Deslackinators? for SRAMŽ Guide and Code-R Brakes ? Matter-Replicator