Bleeding brakes after caliper overhaul

portland_bill

Evening all,

I've got sticky pistons so I think it's about time I split my calipers and gave everything a good clean out.

My only concern is bleeding the system again afterwards. I've seen it done several times before but it's not something I've done myself, but I've got the time and patience so I figured it's time to save some money and do it myself.

I'm fine with stripping and splitting the calipers, replacing seals if necessary, and rebuilding, etc... It's just making sure there's no air in the calipers afterwards that worries me because I can't see how the channelling works until I've split them. Should doing a straight forward bleed with the appropriate Hayes bleed kit be enough to make sure I've done it right or can anyone offer any advice?

Cheers

Kristian

EDIT: Brakes are Hayes Stroker Ryde

nicklouse

dont be worried just follow the bleed instructions.

portland_bill

Ok, cheers man!

jairaj

Yup as Nick says follow the instructions the process isn't terribly hard. You just need to take your time and do things methodically and you should end up with a good bleed. There are lots of videos online too for various different brake manufacturers.

Also you'll know straight away if the bleed is good or not. so little chance of your brakes not working just when you really need them too.

portland_bill

Ok, so I've followed the instructions and done as the videos suggested and I'm just tidying up. It could be because of the clip my calipers were in beforehand but the brakes feel completely different now. I know that's a bit obvious since I've put new bads and discs on, cleaned the calipers and bled the brakes, but there seems to be a little too much play in the levers before the brakes bite.

How much play should there be before they start to bite? I honestly can't remember what the brakes were like when I first got the bike.

nicklouse

So have you been to bed them in yet? No. Just go and use them.

portland_bill

Yeah but my point is, the levers are coming pretty close to the bars. I would have thought with new pads, they should have bitten further away from the bars. As they bed in, surely I'll get even more play on the levers?

I've had to wind the adjusters back out from where I normally keep the levers so that they can be used.

nicklouse

As the pistons settle the levers will move less.

If the Evers are moving and the pistons ate not then you have not got the air out.

portland_bill

Ok, thanks.

Bout time someone developed transparent hydraulic brakes so you can see if there's air trapped in them. I flicked the levers, moved the calipers around and used a canny bit of fluid just to make sure it was a solid stream coming through before I decided I was done so theoretically, the air should be out. I'll maybe give them a week or two to let any remaining air make it's way up the hoses and bleed them again just on the basis that I've split the calipers. It's only a bit of nasty brake fluid at the end of the day compared the risk of another missed season with a bunch of broken ribs.

green room

nicklouse wrote:

So have you been to bed them in yet? No. Just go and use them.

Misread that as have you been to bed in them yet!

If you still have air, take the whole system off the bike, get an old handlebar and clamp it in your vice or workstand, put the lever on the bar, put the caliper on the ground, and bleed caliper up. Give everything a good rattle and shoogle and knock to help the air move. The idea is that if you bleed from caliper up to master then the air will flow upwards naturally. Keep doing this. Knock the caliper all over with an allen key, rotating it around in your hand in such a way that the air is able to move up through the caliper from behind the piston, through port seal, and from behind the other piston and up the line. I have a big syringe with a hayes bleed fitting glued on for the master cylinder fitting to help extract.

If you still have air bleed it the other way up master on the floor and caliper in vice, and then suspect a leak.

portland_bill

Cheers Green Room! I'm going to try that.

I've been using the brakes over the last week or so and they're starting to bed in nicely and get a good bit of bite about them. There still seems to be quite a bit of play in the lever though so I'm hoping all the air should have made it's way up to the master cylinders by now so I'm going to try bleeding them through again but I'll probably try your method off the bike so I don't have to fanny about propping the bike up (not everyone has a workstand!).

Thanks again for your advice!