Shimano 105 7020 hydraulic brakes stopped working

[bogatirj]

Hi.I have an issue with my Shimano 105 7020 hydraulic brakes.Last time i was riding for 60 miles they was working absolutely fine and braking sharply .Yeasterday i wanted go for a ride but after 2 minutes i realised what breakes was squeeling really bad and almost wouldnt stop at all.I went home and inspected them ,then i ve seen what the front rotor was slightly covered with something.I took the wheel off cleaned everything with degreaser and couldnt find any leaks from caliper .At the back everything was clean but same situation squelling when you apply just a bit of pover while holding leaver. I can still feel good tension in the leavers.I ve used that bike only 4 times times so its nearly new.( I bought bike from ebay and the last owner was only using frame of that bike and before sell put all new parts back) Brake pads are Shimano Resin and rotors are 160mm with Ice technology. Bike was standing at home for a month and a half at home since my last proper ride. Maybe anyone have any thoughts on that or experienced similar issue?

[Eyebrox]

You'll need to provide more precise info. What was the "something" on the rotors - dirt or oily looking substance? When you say the lever pressure is good, was it like this previously or has it deteriorated? What state are the pads in - have you removed them to check? Bit by bit you'll get help with this.

[joeegg]

I had a squealing/shrieking problem from new with 105 discs. The only thing that would stop it was cleaning both the pads and discs more or less after every ride. It seemed as if they were picking something up from the road and becoming contaminated. Made the same noise with aftermarket pads.
The squealing isn't unusual because if you watch races or go for a club ride then some discs are noisy.
It got tiresome cleaning them repeatedly so got rid of the bike and went back to old fashioned rim brakes.

[bogatirj]

I would say it was oilish substance at the fron caliper.But after i cleaned it and pressed brake many times no oil was coming out.Also rear caliper was dry and clean but wheel doesnt brake at all also.i thought it might be lose of oil in the system or air but brake handles ar quite stiff when u press them.Many thanks again for your replies

[DevonDamo]

I would say it was oilish substance at the fron caliper.But after i cleaned it and pressed brake many times no oil was coming out.Also rear caliper was dry and clean but wheel doesnt brake at all also.i thought it might be lose of oil in the system or air but brake handles ar quite stiff when u press them.Many thanks again for your replies

If you're feeling good pressure through your levers, but getting no braking, then you've almost certainly got contaminated pads. Don't underestimate how much effect this has - when I've managed to get chain lube on my pads, the brakes have faded away to nothing. You will find instructions online for decontaminating pads, using heat, solvents and/or abrasives, but I've only ever had very short-term results from this - the brakes will fade away again eventually (although you usually find that if you ride down a very long hill whilst dragging the affected brake, it will come back to life, presumably because the generated heat is boiling off the contaminant from the friction surface.)

If I were you, I'd do an online search for cheap online suppliers of quality brake pads, and get a few pairs. Clean the caliper and disc thoroughly with generous amounts of brake cleaner before installing the new pad, and make sure you don't risk any further contamination whilst testing it out - i.e. hold off on lubing your chain etc. If the new pad does the same thing, the most likely explanation is that brake oil is leaking from your caliper(s) which you'll need to replace.

[slowster]

I would say it was oilish substance at the fron caliper.But after i cleaned it and pressed brake many times no oil was coming out.Also rear caliper was dry and clean but wheel doesnt brake at all also.i thought it might be lose of oil in the system or air but brake handles ar quite stiff when u press them.

I suggest you follow the procedure detailed by Brucey in this post: viewtopic.php?p=1369700#p1369700, to confirm definitively whether either - or both - of the calipers are leaking.

[bogatirj]

Thank you very much everyone for your replies ! I will go trough your advices and hopefully get it fixed .Many thanks !