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Swapped the pads in my Code R's yesterday and the brakes are now super spongy. All I did was push the pistons back into the caliper and change the pads. Despite not opening the closed system, do they now need a bleed?
Sounds like it...pushing the pads back would have forced fluid to push any air around and it has now moved...a 'quick' cheat would be to lock the brakes on overnight...the air tends to then moved up to the lever where it doesn't feel as spongey (and is easier to fill the reservoir to remove the air if you don't want to do a full bleed. It isn't a total solution but it does tend ton work for a bit.
Yes, they need a bleed. Quite likely the seals in the calipers were dry and needed lubing. When that happens, air can get past the seals. A film of brake fluid on the seals helps them to seal properly.
Remove the pads and carefully squeeze the lever to move the pistons out. Clean the pistons with dish detergent and a toothbrush, then wash off with hot water. After that, put a few drops of brake fluid on each piston so that it's fully coated and then carefully push the pistons back in. Then wash the calipers with dish detergent and hot water again to get rid of any excess brake fluid.
Once you've done that, bleed them and refit your brake pads.
Not saying the above are wrong but in my experience new pads* can create a spongy feel until they are bedded in.
*Not all of them, just some.
I haven't even ridden it yet! I can pull the levers back to the bars and push the bike forwards.
Did you turn it upside down to replace the pads? Good chance there was air in the reservoir and that got into the master cylinder. Whatever the case, bleeding is the first thing to do.
If you fully retracted the pistons and put the new pads in, it will take a few lever pulls to get everything reset and working again - so the levers are likely to hit the bar for 4 or 5 pulls until the pistons move out and stay where they are meant to be.
Yeah, I've done the old pumping the lever thing. I'll try locking the brakes on tonight and see what they're like tomorrow.
Sound like the brakes need a full bleed...very lazy way, attach fully loaded syringe at caliper end, and then attach a 1/5th filled syringe at lever end, push full syringe with a bit of effort at caliper and watch the syringe at lever end rise...it should also have plenty air bubbles in it.
Once it has been filled, leave the lever syringe in place and close off the caliper bleed nipple. Then pull the syringe plunger upwards...any more air will be drawn up into the syringe. Once done, remove syringe and reattach bleed nipple.
Not really a proper bleed but a quick way to get a lot (if not all) the air out the system and fresh fluid in. Plenty companies suggest not doing this as it can force dirt up the system, but I've found if it does, then the dirt quickly ends up in the upper syringe.
Did you open the span adjuster of the lever before pushing the pistons back and pads in? For some reason it does make a difference when I fit new pads to Guides.
I'm sure you know the what and how but I found this YouTube guide by Doddy great with some small details at the lever end that made a difference when I bled the brakes. Oh and isn't the Bleed-a-ma-jig fabby....
Yeah, I like that video...I consider that a full and proper bleed and I tend to take my time with it...but a quick bleed can help get the worst of the air ot the system and a quick flush with fresh fluid always helps.
A full bleed is the right thing to do, but it takes a bit longer.
It turns out that one of my mates has the Epic bleed kit so I bled the brakes last night. The Front is now OK but I'm not happy with the rear after two attempts; it's better, but I'm not sure that it's good enough for a BPW trip and I'm not riding before then to test them out.
Rear brake always seems to take a bit more time and effort, I'm sure it is down to the length of the hose. Did you remove the brake from the bike so the hose was a vertical as possible? I suspect that also helps get rid of all the air.