Feedback Loop

FeedbackLoop

Q In reading your Service column in my back issues of Cycle World, I came across your reply to Martin Katz ("Ghost in the machine," September, 2010), who had an unprovoked rear-brake lockup when riding his KTM. You gave a very good explanation as to the probable cause, but I'd like to add something that I had never before seen in all my years of "pulling wrenches."

I own a GMC pickup that did a similar thing, i.e., the right-front brake stuck on. I changed the caliper, and while bleeding the system, I noticed very little flow to that caliper. Upon further investigation, I discovered that the rubber brake hose had an internal problem. The hose showed no exterior cracking, and when I went to my parts store to order a new hose, the boys there said that the rep from Bendix and Raybestos had been

at the shop a week prior and told them this was something to watch for. The inner hose deteriorates, and neoprene particles then clog the hose internally. I replaced all the hoses on the vehicle and the problem never again surfaced. I probably could've saved myself the cost of a caliper had I looked a little closer. Rod Roberts

Posted on America Online

AI never found out if my diagnosis was on the mark or missed it entirely, and I also have no clue if the material used in KTM rear brake lines is similar to that in GMC pickups or, for that matter, any other car or truck. But regardless, your explanation certainly seems plausible, and I will remember it for future reference. Thank you very much for the hands-on input.