Brake Pad Sensor didn't do anything, caliper bad?
Thread Starter
Member
Joined: Nov 2015
Posts: 133
Likes: 11
From: Campbell, CA (San Francisco Bay Area)
2013 GLK250, 2022 Tesla MYLR, 1997 Correct Craft Ski Nautique
Brake Pad Sensor didn't do anything, caliper bad?
So, I ground into the front right with no warning of any kind. I was thinking that maybe my model didn't have pad wear sensors, but I found it does on one pad of each front wheel (didn't look at the rears but assume the same). However, the pad with the sensor wore more slowly than the pad without a sensor, so I started grinding before the sensor would have done anything. I heard that calipers might be under warranty. I saved the pads and rotors so I could take them to the dealer. I'd love to have them give me new calipers since it cost me new rotors (rather than having them turned). Anyone else have this problem? Kinda dumb to have wear sensors only on one side unless you're absolutely positive they will wear the same speed.
Gordon
Gordon
Super Member
Joined: Aug 2011
Posts: 861
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From: Philly area
350 GLK, C280
Weird that the pads didn't wear evenly. When you say pad with sensor, do you mean the left wheel pads wore down quicker than the right wheel's or that the outer wore quicker than the inner on the one wheel?
There is usually quite a bit of material left on all pads when the sensor is cut. If the two wheels wore that much differently, I would look for a problem in the brake lines or master cylinder. Check to see if the opposite rear pads are much smaller than the other rear, although the rears wear much slower. If so you are only using one circuit to do most of the stopping. Could be a problem with the master cylinder of equalizer.
If the two pads on the same wheel are wearing differently, I would suspect that the caliper is hanging up. Did you replace it or have it rebuilt?
Sensors on one pad for the front and the back has been a very successful system for many years. Although the cost of the sensor is less than a buck, saving 2 per car, for a million cars per year adds $2 million to the bottom line per year.
Ford took the electrical contacts out of the radio on-off switch back in the '70's. The knob turned the volume to zero and the radio went off with the ignition key. Save 20 cents per car. Two million cars per year, $400k savings. No Harm done, the guy who suggested it got ???.
There is usually quite a bit of material left on all pads when the sensor is cut. If the two wheels wore that much differently, I would look for a problem in the brake lines or master cylinder. Check to see if the opposite rear pads are much smaller than the other rear, although the rears wear much slower. If so you are only using one circuit to do most of the stopping. Could be a problem with the master cylinder of equalizer.
If the two pads on the same wheel are wearing differently, I would suspect that the caliper is hanging up. Did you replace it or have it rebuilt?
Sensors on one pad for the front and the back has been a very successful system for many years. Although the cost of the sensor is less than a buck, saving 2 per car, for a million cars per year adds $2 million to the bottom line per year.
Ford took the electrical contacts out of the radio on-off switch back in the '70's. The knob turned the volume to zero and the radio went off with the ignition key. Save 20 cents per car. Two million cars per year, $400k savings. No Harm done, the guy who suggested it got ???.
Thread Starter
Member
Joined: Nov 2015
Posts: 133
Likes: 11
From: Campbell, CA (San Francisco Bay Area)
2013 GLK250, 2022 Tesla MYLR, 1997 Correct Craft Ski Nautique
Sorry, I didn't explain very well.
The outboard pad on my front right caliper wore faster than the inboard pad. The pad sensor is mounted only on the inboard pad. So I started grinding on the outboard pad while the inboard pad still had sufficient pad that the sensor didn't do anything. Had they both worn equally, I would have gotten a warning before I ground the rotors.
As for left vs right, overall the same although on the left side, both the inbound and outbound pads wore evenly. So I see a problem with the right front caliper since I'm not getting even wear. Based on how it is mounted, I wouldn't think there is a binding issue where the caliper is not moving freely. But I could be wrong. There are no caliper pins to grease/lube. On other cars, that has been what has caused uneven wear between the outboard and inboard pads.
The outboard pad on my front right caliper wore faster than the inboard pad. The pad sensor is mounted only on the inboard pad. So I started grinding on the outboard pad while the inboard pad still had sufficient pad that the sensor didn't do anything. Had they both worn equally, I would have gotten a warning before I ground the rotors.
As for left vs right, overall the same although on the left side, both the inbound and outbound pads wore evenly. So I see a problem with the right front caliper since I'm not getting even wear. Based on how it is mounted, I wouldn't think there is a binding issue where the caliper is not moving freely. But I could be wrong. There are no caliper pins to grease/lube. On other cars, that has been what has caused uneven wear between the outboard and inboard pads.
