Hi any advice would be most gratefull.

My back brake leaver was very sponge and would go all the way to the bar and would hardly stop me at all.

So thought would try bleed first time. watched videos on Youtube and seemed quite straightforwd.

Took out pads was going to replace them but almost looked identical to the new ones so thought would leave them.

1 pushed back the pistons with tyre leaver.

then as i did not have shimano bleed spacer i used a 10 m allen key.

I did what they said on you tube with squese brake open bleed valve let fluid out , close refill with fluid and repeat.

I did this a few times till my brake leaver was very hard/stiff .

I have now put the origanl pads back in, but they still feel the same with no braking power and brake leaver goes all the way back to the bar .
Also thought would try adjust the caliper , by loseing it spinning wheel then brake and then tighten, but still no luck .

Any advice ? apart from changing pads , as this would still not result in leaver going back to the bar ?

pump the pistons out as far as you can without them dropping out then rebleed

Thanks , so pump them out with no spacer in , then push them back in and rebleed ?

pump them out, say 3 mm or as far as you dare, then slot an allen key smaller than 10mm in there – for example a 6mm or 5mm – to hold it still and bleed with that in place.

I had the same symptoms as you and that fixed it – i think it was air stuck in the pistons

the other thing worth trying is a bottom up bleed using a syringe. Try pushing and pulling gently on the plunger to see if any air bubbles plop out, it’s oddly satisfy 🙂

As the pistons are ceramic if you use metal to wedge them / prize them back, just go easy on them or use something plastic

It’s quite easy to crack the pistons. Check you havent already got a leak!

If bleeding top down (sounds like you are) make sure fluid doesn’t drop too far otherwise you push air through.
Are you closing the bleed nipple before releasing the lever – if not air will be going back in that you just expelled.
With reservoir topped up rapidly release and tighten the bleed nipple ten times
Tap the caliper with a spanner r or screwdriver to release air bubbles
Pressure bleeding from the bottom works great for really air filled brakes
Tenacity, patience, a brew and Donnie Darko on the garage telly are your friends

One more thing keep bleeding after the lever gets hard as its no guarantee all the air is out.
My money is on air in pistons so keep at it

Many thanks guys for advice well try sort it out when got a spare hour or so.

Syringe full of fluid, lever top caps off, fill brakes from bleed end instead. Works fantastically on old single pot shimanos like the lx585’s. I take it the design hadn’t changed much over time has it?

I fill from the caliper, tap the caliper with the plastic handle of a screwdriver to dislodge bubbles, flick hoses for the same reason, lean/tilt/hang bike to create a continuous slope for the bubbles to rise from caliper through the hose and out of the lever, and leave it in that position overnight – always find a few more little bubbles in the morning when the lever is very lightly pulled.

Hope that helps 🙂

Did you top up the reservoir to the brim before reinstalling the rubber diaphragm and reservoir cap?

I would recommend a re-bleed with the syringe method, like the other guys have already suggested. I feel it is a much more efficient method.

So i managed to find a spare hour to get to my cave to try sort out the brakes, not 100 % sure if this correct , i read as the pads where the calipers push the pistons out further to compensate for this.

But I noticed only one side would compensate is this correct ? as one would still move in and out but not really come out well the far side caliper would come out almost 7mm.

Also managed to get the brakes bleed (I Think) as when I pull leaver it very firm , Like how it used to be when new, but still no braking power it a lot better that it was before BUT now it makes a horrible squeaking sound , ( may this be the result of contaminated pads ?)

Both pistons should move evenly, and not retract by large amounts when you release the lever. My first thought was this when I read your original post, if the piston isn’t self adjusting, then you’ll be using most of your lever travel trying to close the gap to the rotor, squeal may just be down to distorting the rotor because of the unequal pad pressure on it.Sounds like your caliper seals and pistons could do with a clean and lube to get them moving freely.

Sorry to bump this but after this dont think i am goin to take any thing to my bike apart from a hosepipe.

I manged to bleed the brakes again , and cahnged the pads which sorted out the squealing and all was fine , but since taking it for a proper ride i found if i was to brake quite frequently that the stopping power was getting worse and worse. So I decided to Bleed AGAIN. Here where it all went wrong again.

I still noticed that only one piston would come out and keep coming out (with no pads in there ) well the other one would come out and then go back in and not adjust. So i pushed them both in to start the bleed, but I think i may have pushed them into far and posibly broken them as when i pullled the brake leaver the pistons did not move at all and strange thing is that bubbles came up out the top of the brake . I then manged to get one piston to start working and stupidly pumped the whole thing out, and shits load of fluid came out from the caliper , after a bit of hassle manged to get psiton back in.

But when i started to pull brake leaver nothing happpens with pistons, Also weird thing was that if i pumped brake leaver and open the valve on the caliper no fluid would come out at all.

Sorry gramer not the greatest , and a lot of waffle . Hopefully you almost get waht i am talking about.

Basically is there any thing i can do or just bite the bullet and buy new brakes ? As dont think pistons working.