Shimano brakes after riding through puddles

swaz

swaz

Likes Bikes and Dirt
So I rode through some deep and muddy puddles during the week and my brakes (Shimano M445 resin pads) have this grey coating of dust all over it and the braking performance was shyte house. Took the wheels off and cleaned the rotors with metho and the front pads with metho. But they dont seem to work as well as they did. I can pull the lever in hard and still give the bike a shove forward and the wheels move; if that makes sense.

Ive searched it YouTubed it and can't find a solution to this individual issue. Should I get disc brake cleaner for cars and do it that way? Isopropol alcohol for pads and discs?
 
pharmaboy

pharmaboy

Eats Squid
You've returned your brakes to pre bedded in state. You need to now do a bed in procedure which pretty much much means getting upto a decent speed on a flat road and using the brakes hard but not quite to a stop, then repeat 10 times.

You've just washed the brake material off the rotors.
 
swaz

swaz

Likes Bikes and Dirt
Ah ok, that makes sense. So metho is OK to clean resin pads with? I haven't done the rear yet.
What is the grey dust?
 
moorey

moorey

call me Mia
swaz said:
Ah ok, that makes sense. So metho is OK to clean resin pads with? I haven't done the rear yet.
What is the grey dust?
Click to expand...
Metho fine
Acetone better
Isopropyl best.

They shouldn't have got shitty performing in the first place though. I've ridden through all types of mud over the years and haven't had this happen :noidea:
Didn't ride through an oil slick, did you? If the above doesn't work, your pads might be contaminated. Clean rotors again, and cook your pads on a BBQ or stove top, pads upwards, until they stop smoking and stinking. Allow to cool naturally and re-bed them in.
 
R

richie_gt

Likes Bikes and Dirt
swaz said:
Ah ok, that makes sense. So metho is OK to clean resin pads with? I haven't done the rear yet.
What is the grey dust?
Click to expand...
I wouldn't recommend cleaning the rotors or pads with any liquid/solvent - a quick hose of water is enough to get rid of mud/loose dirt. For anything that doesn't budge use a clean dry rag.

Usually braking performance dips after the pads + rotors get wet, after you've cleaned the bike take a quick ride down the street and do half a dozen hard stops from speed, that will get rid of any moisture and then you'll be ready to go next ride out!
 
swaz

swaz

Likes Bikes and Dirt
Is Isocol rubbing alcohol ok to use? Is it pure isopropyl alcohol?

Sent from my GT-I9100 using Tapatalk
 
Urban DH

Urban DH

Likes Bikes and Dirt
in theory and alcohol based solvent SHOULD be ok based on the theory that alcohol evaporates rapidly. How ever a good go on the bbq or with the propane torch should clean All the crap out or rather burn it out, be resin pads might turn to shit, all else fails 600p wet and dry on the braking surface and I mean a good rub, a wipe with metho (or rather I soak mine and then light em up, work much better) and new pads, and if the fails go avid :)
 
swaz

swaz

Likes Bikes and Dirt
I did as suggested and washed them, wiped the rotors over with metho and bedded them back in and they were as good as new. However I think they got some crap on them from the holiday trip away on the back of the car and aren't has good as they were.
I am secretly hoping they stay that way so I can get some slx ones:) but I got some Isocol and thought that might be better than metho.
 
Last edited:
Fatherpaul

Fatherpaul

Likes Bikes
A word of caution, I have read elsewhere that one should NOT cook pads at all (aka BBQ hot plate, oven or propane torch) as it can increase the risk of the the pad material coming away from the backing plate.

I find that cleaning Shimano pads under running water by rubbing the pads together for a couple of minutes cleans them up nicely. Then dry in the sun and just a firm wipe over with a clean rag does the job.
 
You must log in or register to reply here.
Top