Bleeding old shimano m525 brakes
ps4customgamer
Posts: 34
So I have an old pair of shimano m525 brakes and I think theyre really solid except the rear which needs bleeding and new pads. I've checked the instructions and they tell you to do a very old fashioned bleed with a tube and bag but I dont have a bleed block so trying to do this without isnt working all I'm doing is getting air into the system.
http://www.bike-manual.com/brands/trek/ ... 25_eng.pdf
I was hoping to use a syringe to replace the 14yo oil in the system but when I've tried the system seems to be blocked by the levers, with the levers disconnected oil will push through the calipers and brake line but is blocked by the levers.
Does anyome know if its possible to undo a bolt on the levers so oil can bleed through them unrestricted or are they just not compatible with the 5 minute refill method?
https://www.youtube.com/watch?v=DsqlEYJeLQU&t=10s
I dont believe for a second the shimano factory paid workers with a tube, bag and spanner to spend hours bleeding new shimano brakes so I'm clearly missing something.
http://www.bike-manual.com/brands/trek/ ... 25_eng.pdf
I was hoping to use a syringe to replace the 14yo oil in the system but when I've tried the system seems to be blocked by the levers, with the levers disconnected oil will push through the calipers and brake line but is blocked by the levers.
Does anyome know if its possible to undo a bolt on the levers so oil can bleed through them unrestricted or are they just not compatible with the 5 minute refill method?
https://www.youtube.com/watch?v=DsqlEYJeLQU&t=10s
I dont believe for a second the shimano factory paid workers with a tube, bag and spanner to spend hours bleeding new shimano brakes so I'm clearly missing something.
0
Comments
-
You cannot bleed those brakes unless you remove the reservoir cap on the lever, otherwise you are pushing against a closed system.
The instructions you linked to show what to do. You don’t need a bleed block if you leave the wheel in situ. Otherwise just put a suitable sized piece of wood or LEGO between the calliper pistons.“Life has been unfaithful
And it all promised so so much”
Giant Trance 2 27.5 2016 ¦ Sonder Broken Road 2021¦ Giant Revolt Advanced 2 2019 ¦ Giant Toughtroad SLR 1 2019 ¦ Giant Anthem 3 2015 ¦ Specialized Myka Comp FSR 20090 -
JBA wrote:You cannot bleed those brakes unless you remove the reservoir cap on the lever, otherwise you are pushing against a closed system.
The instructions you linked to show what to do. You don’t need a bleed block if you leave the wheel in situ. Otherwise just put a suitable sized piece of wood or LEGO between the calliper pistons.
I tried in situ as you said but it just doesn’t move enough after about an hour no difference in fluid levels in my reservoir, my brake pads and discs are fresh.0 -
If you want to quickly flush the old oil out, you can remove the hose from the lever, push new fluid through from the caliper with a syringe (obviously make sure that the hose is pointing at a suitable receptacle) and empty the lever. Then, when you reconnect the brake hose (which will be full at this point), close the bleed nipple at the caliper, fill the reservoir with fluid and pump the lever while giving it a few taps to get any trapped air to escape. Then, if it still feels a bit spongy, follow the usual bleed instructions.0
-
If the free travel adjust has been wound in too far it blocks the return flow path, you need to wind it back out.
Had this on some old LX brakes (M665) I bought on a bike.Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.0