Depends on the level of contamination but you will probably get way with a good clean with solvent as David suggests
Having said that, I recently changed a set of brake shoes which had been contaminated as a result of a hub seal failing. Shoes didn't seem too bad, cleaned them up perfectly and went in for a brew. Came back after 10 mins, they were as filthy as before. Cleaned them off again and you could see the oil seeping out of the friction material. Bought a new set in the end!
Arwyn
