Just picked up a GT for a winter hack - the hydrolic breaks were not too hot - though the previous owner had soaked the bike in wd40
So I slipped them out - light sanding and cleaned everything with isopropyl alcohol- on reassembly they are just rubbish and don’t even bring the wheel to a stop
Have I made a school boy error?
Ta
Untitled by biglewie, on Flickr
Untitled by biglewie, on Flickr
Last edited by lewie; 15th February 2019 at 16:18.
If the pads have had WD 40 on for any period of time them the pads will be toast. You sound fairly practical since you have removed them, I would just do two further checks.
1) Have you wipedthe disks down with Ipa. Start at the edge of the rota and work in, so non of the axle grease gets on the braking surface.
2) Are the hydraulics working, eg are the pads touching and then squeezing the rota? A bright light pointed down by the caliper will show this.
3) I the pads dont move with much force then its good old fashioned brake bleeding which is painful on a bicycle as they only have about 2cc of fluid in the reservoir.
If 1&2 are OK I would invest in new pads. Often Halfords ON LINE is as cheap as Chain Reaction and Wiggle. If you cant work out the make or model of the pads , pop along to a local bike store
Hth
agreed. If WD40 or GT85 have been near the pads they'll be dead.Originally Posted by higham5
You could try cooking the pads on an oven ring, it's worked in the past for me.
If you need new pads make sure the rotors aren't 'resin only' before making the mistake of mating the rotors with sintered pads.... I've done that before and wondered why the brakes feel wooden.
Last edited by RD200; 5th February 2019 at 19:58.
I use a large syringe to slowly push the fluid up from the bleed nipple, don’t even need to bleed them afterwards.
Good tip, I come from a motorcycle background so I have bled them like that, nice touch to start from the bottom as they have bugger all at the top.
Steve
I don't have much experience of push bike disc brakes but saw this article recently and bookmarked it for future reference as I have bought a bike with disc brakes..
https://road.cc/content/feature/2330...mance-out-them
Discs and electronic gears...the two things concerning bikes that I know nothing about.
I bled my shimanos from top to bottom and back to top again with a burp to finish off.
As has been said, bin the pads and fit new ones (you could always replace the discs as well if they look a bit rough as they're not that expensive). Make sure to bed them in before you go off for the first ride.
What brakes are they by the way?
Thanks all - I’ll check it out tomorrow- I’ll start by bleeding them as they seem very spongy then take it from there
Thanks
everything looks in good conditon - and after a ride in to work this morning they are working(sort of) but the leaver needs to be pulled right to the bar- cold it just be a case of needing to be bled?
Simple tip, on the principle air rises through the oil, today at work or overnight, pull the lever on as much as it will go. In you case back to the bars. Then hold it there with an elastc band around the bars or tape. This opens up all the valves and allows air to percolate up into the reservoir
When you return to it tonight , take the tape elastic off, et voila
Last edited by higham5; 6th February 2019 at 08:50.
Yes. Sounds like they just need bled. Check what type of fluid they need and buy the appropriate bleed kit from a bike store or eBay (usually just a few syringes and hoses sometimes with specific fittings).
I've found different manufacturers brakes often need different techniques for bleeding. Loads of tips here so I'm sure you'll figure what works.
Last edited by mowflow; 6th February 2019 at 11:03.
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