PSA: Choose the lubricant for the rear brake caliper slide pins carefully

Sep 19, 2018
New York
About 2 months ago, I did a rear brake job on my LX. About 6 weeks later, a grinding noise had started in the rear. I checked it out, and the inner pad on the passenger's side rear caliper was worn down to the backing plate. The outer pad still had full thickness. The rotor had deep gouges on the inside face as a result. I figured that my brake job, specifically when I compressed the calipers, had kicked loose some rust in the caliper, causing it to stick or freeze. As a temporary measure, I installed some cheap pads, and then I ordered 2 remanufactured calipers for the rear, along with brake lines and pads, as well as a rotor for the one that was wrecked. Yesterday, I went to swap those parts on. Some time in the last 2 weeks, the driver's side rear caliper also began sticking. I replaced the calipers, soft brake lines, pads, and rotors, but in doing so, I realized that the calipers and lines were actually okay, though I don't regret swapping 25 year old parts for new, especially when it comes to brakes. What has happened was the brake parts lubricant that I used on the slide pins had reacted with the rubber boots for the slide pins, causing the boots to swell, freezing the calipers in place. I had been using Permatex 24125 Ceramic Extreme Brake Parts Lubricant for years without issue, but I've never used it on a vehicle with slide pins before. I did a little research, and that lubricant has a known reaction to rubber, even though Permatex says you can use it on slide pins. The "correct" lubricant which doesn't react with rubber is Permatex 80653 Silicon Extreme Brake Parts Lubricant. I installed everything yesterday and used that lubricant on the caliper hardware and slide pins. So far, everything works beautifully. I'll continue to monitor the status of the rear brakes though.

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