First-time Hydro Disc Brake Setup... Tips/Tricks?

[xeladragon]

I just ordered the Shimano RS685 shifter/brake set... looking forward to trying hydro discs for the first time!

For the most part, I do my own wrenching, but I've never worked with hydro disc brakes before. I watched a few YouTube videos last night... doesn't sound too bad.

Any installation tips/tricks/advice? Do I need any special tools other than a bleed kit?

BTW, if anyone in the Boston area wants to help me with installation, I'll pay you with the beverage(s) of your choice. :)

:help: Thanks!

[ergott]

I didn't do anything different than the videos I watched. Only thing to consider is the lever angle so that the reservoir is facing all the way up which means the lever is pointed up more than the position you have them in when riding.

Tap them with a plastic hammer (or the back of a screwdriver) to knock the bubbles up to the top. Be patient and keep repeating until the lever feel is firm when the caliper contacts the yellow plastic block (don't do the install with pads and rotor in place).

[oldpotatoe]

I just ordered the Shimano RS685 shifter/brake set... looking forward to trying hydro discs for the first time!

For the most part, I do my own wrenching, but I've never worked with hydro disc brakes before. I watched a few YouTube videos last night... doesn't sound too bad.

Any installation tips/tricks/advice? Do I need any special tools other than a bleed kit?

BTW, if anyone in the Boston area wants to help me with installation, I'll pay you with the beverage(s) of your choice. :)

:help: Thanks!

If shortening a line, you may need fittings/acorns/banjo fittings type stuff and Shimano fluid.

[vqdriver]

if the lines dont need shortening, then theres little to know. if you do need to cut them, it's possible to do without bleeding but very touchy to do so. i'd mark the length and cut/bleed off the bike for the first time. not rocket science but can be intimidating the first time.

[dustyrider]

Put your brake pads in another room!

[ergott]

I assumed new units don't come pre-bled with the system all set up. When I got 785 hydro the lines weren't installed yet.

[commonguy001]

My set of hydros wasn't assembled either when I got them. Having never worked on Shimano hydros I found them super easy to set up. No surprises, just needed a bleed kit with funnel.

Didn't use a syringe as my bleed kit didn't come with one and I didn't find I needed it.

[11.4]

There are two ways to bleed them -- adding fluid from the bottom and adding it through the top (in the funnel). In either case you really, absolutely, need the proprietary Shimano bleed funnel and related hardware. Some people prefer working from the bottom, others from the top (stop with the wise ass comments, some of you). For a first bleed with a dry caliper, lever, and hose, I've found I prefer to pump from the bottom with a syringe and let the fluid rise and gather in the funnel at the top. Until the inner surfaces are wetted it seems to get rid of bubbles more easily because you are dynamically pumping fluid through, where going from the top just means it flows and has to displace bubbles with less force. In either case, tilt the bike so the handlebars are up and the funnel is sitting vertically.

Depending on your caliper mounting, remove the calipers and let them hang straight down by the hose. Vertical alignment helps a lot with bleeding.

Hanging the calipers free from the frame makes it a little less messy as well. Mineral oil seems to get everywhere and if you pop a connection and have a leak, it's downright messy. Definitely have a spray bottle full of 90% isopropyl alcohol (from any pharmacy) and use it a lot to keep everything clean. Just assume your hands (or gloves) will be slippery with mineral oil, as will the calipers themselves. I tend to agree about removing the pads from the calipers until the bleeding is complete. If you get mineral oil on pads, it's pretty much time for new pads.

As always with hydraulics, don't pull the levers without either a rotor or a dummy spacer between the pads. If you do, the pistons drive the pads together and the pistons won't retract on their own. You have to hassle with a plastic tire iron or similar tool to pry them apart again, and in the process you can get more air in and then have to start the bleed all over again.

Forget what you may have seen or experienced about mountain bike hydraulics in the past. These are the easiest things in the world, as long as you have the bleed kit with the funnel (and preferably the syringe). The first time is slow and tense, after that, it's a snap.

[xeladragon]

Thanks guys... hopefully things go well!

[Gummee]

Good news! Shimano brakes are about 'bang two rocks together' simple to bleed.

I like the 'bottom up' method 'cause air bubbles naturally want to go up.

M

[macaroon]

Put your brake pads in another room!

:D

I don't know how similar they are to MTB units I've worked on in the past. Bottom up bleeding works best I used to find. Do they have an adjustment to wind the pads in and out? If they don't, and you find that your levers are pulling in too far before the pads contact the rotor; simply take the wheel out and squeeze the lever slightly (just enough to move the pads in a bit) then refit the wheel and voila, your pads will make contact sooner.