Does grease kill a rim brake pad?
 

If you get grease on a rim brake pad is it ruined? I just heard that it is, that nothing can save it. I never knew that. I'd think you could just wipe it off and wash it then use it a bit and it would come around. I assume that I've gotten WD40 and other lubes on my pads before. Hmmm... never knew grease could kill a pad. ??

That kind of applies to disc pads,

but all of my rim brake pads have survived all manner of stuff for many years.

Agree. There's so much road contaminate of the liquid type that drips off cars and trucks and the rims are so close to the road surface that if this was a real issue it would have been made known a long time ago. I've worked in shops that clean the repairs with WD40, rims and all. Their customers were able to stop and their pads didn't seem to be bothered long term by this cleaning.

What's motivating your to question the pads and grease? Of course if you lube the braking interface the friction will drop down big time for a little while at least. But cleaning with a true solvent removes any lube and pretty much restores the friction. Andy

Rubber based rim brake pads have a pretty good tolerance to being rehabilitated after having been exposed to greasy contaminants unlike disc brake pads. Clean them off using a product that doesn't leave an oily residue and they will be fine

It’s the materials of construction that matters. Brake pads for rim brakes are made of rubber and nonporous. Any grease that gets on it is only on the surface and will usually just wear off with braking. You might be able to get grease to migrate into the pad with a lot...a lot...of time but, for the most part, it will come right off.

Disc brake pads are a phenol/formaldehyde resin that is also sintered. That means the pad is much more porous. Grease that gets into the pad gets sucked into the inner part of the pad and never really wears off. You can use solvents to remove the grease from rubber but solvents would just drive the grease deeper into the disc pad.

Agree with all the previous posters. It may be a problem with some pads and using them on a mountain descent on a hot day but if cleaning the pads and rim doesn't work just sand down the pad surface to fresh material.

If you REALLY want to be sure there's no residual contamination, do this:
1. Wipe the brake pad off with liberal amounts of isopropyl alcohol on a clean rag.
2. Sand or grind the surface of the brake pad enough to expose fresh, unadulterated (UV light, ozone) brake pad compound.

This advice applies best to road or cantilever pads with adequate material. "Slim" v-brake pads may not apply. This DOES NOT APPLY to any disc brake pads!!!!
I sand or grind brake pads when servicing bikes. Easiest way to renew the pads to as "new" a condition as you can.

This, however, assumes there's enough material there to start with. AND that you do so sensibly. Make sure the surface stays flat and perpendicular to the mounting post/bolt. And that you preserve any "pre-toe" the pad may have (KoolStop). Observe and heed any "maximum wear" lines that may be printed on the pad.

If you can't do this to a pair of pads because they have so little remaining material left, then they're too toast to use in the first place.

Use this advice only if you know what you're doing.