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Use an old sensor wire for future testing of circuit
Hello, I know this is a slightly older thread, but I just wanted to share: for those of you who are going to replace a brake pad wear indicator sensor, do not throw away the old one. Instead, cut the wires above the first sensor point and solder the two ends together and cover with heat shrink. This can then be used in the future to test for any faulty wear indicators and will also act as a temporary fix until you have time to fit a new one. Here’s a photo of the one I made:
I do this on one side per axle, so that I only have to replace one sensor per axle. They have so much safety margin I really don't see the point in the redundancy of two.
Sorry I have to weigh in on the above two posts.
I'm all for bypassing a useless alert but not on brake pad wear indicators, and not on these heavy SUV's.
Each sensor covers 2 pads not one so you are blind to the whole side if you purposely disable. And one side can easily wear through, uneven wear is the norm both across pads and between sides. Then you can have one side stopping and the other side not (especially in front) is a recipe for disaster. Not sure your insurance will cover you if you have purposely circumvented the safety system. Something to think about.
And these sensors are cheap, especially because you only need to buy one. When one does trigger you need to find out which side is still good so you can keep that. To unit test these all you need to is complete a circuit, so unplug the connector on the shock tower and connect two leads of an ohmmeter testing resistance. If the screen changes and shows ANY resistance at all then you have a circuit and you can reuse that sensor when you change pads even if it started to wear a little - just be careful removing it, I swear they use bakelite on the pad sensor part that crumbles if you squeeze too hard.
One more thought. If someone brought their car to me with that soldered bypass I would probably refuse to let them go without fixing it or make them sign a liability waiver and ask them not to return. So you may wind up spending much more to have a pro do it or burn a bridge by refusing. If you order new pads now and change based on the groove in the pad (before the sensor triggers) you can save that expense too and take advantage of sales on pads so you are ready.
Sorry I have to weigh in on the above two posts.
I'm all for bypassing a useless alert but not on brake pad wear indicators, and not on these heavy SUV's.
Each sensor covers 2 pads not one so you are blind to the whole side if you purposely disable. And one side can easily wear through, uneven wear is the norm both across pads and between sides. Then you can have one side stopping and the other side not (especially in front) is a recipe for disaster. Not sure your insurance will cover you if you have purposely circumvented the safety system. Something to think about.
And these sensors are cheap, especially because you only need to buy one. When one does trigger you need to find out which side is still good so you can keep that. To unit test these all you need to is complete a circuit, so unplug the connector on the shock tower and connect two leads of an ohmmeter testing resistance. If the screen changes and shows ANY resistance at all then you have a circuit and you can reuse that sensor when you change pads even if it started to wear a little - just be careful removing it, I swear they use bakelite on the pad sensor part that crumbles if you squeeze too hard.
One more thought. If someone brought their car to me with that soldered bypass I would probably refuse to let them go without fixing it or make them sign a liability waiver and ask them not to return. So you may wind up spending much more to have a pro do it or burn a bridge by refusing. If you order new pads now and change based on the groove in the pad (before the sensor triggers) you can save that expense too and take advantage of sales on pads so you are ready.
I can agree to this to an extent. For the average every day driver that drives their Cayenne S to and from work, soccer, etc. and doesn't turn their own wrench, then yes I agree and disabling the brake pad wear sensors does more harm than good. However, for most of the users on this forum. I don't feel that we as enthusiasts need a sensor to tell us when our brake pads are low. We are "in tune" with our car and know when its due for service, etc. I put a big 8 pot PB Brake kit on my 09 Turbo S and I yanked all of the brake pad sensors off because they were useless with aftermarket anyways. I know my car well enough to know when the pads are getting low and I will be putting this trick to use when I put new pads on. I have the sensors and I'm just going to solder them together and close it off to shut off the alert light on the dash. I can see this both ways; depends on the application and who is driving!
My old 911 only has wear sensors on the inner pads of each caliper. My BMW X5 only has wear sensors on one pad on one wheel in the front and one wheel in the rear. I consider those both safe, as well as the suggestions above. I've even driven cars without any wear sensors at all, except for the metal tang that scrapes the rotor.
Safety is important, but at some point it's important to consider the safety level of everything else in the system (like other cars) before making one thing perfect.
I realize people who fix cars professionally have other factors to consider here.
I expect that anyone who knows what a wear sensor is, and knows how to circumvent it is sufficiently in-tune with their vehicle that it is safe to do.
I can see your points.
If you bring your car for race prep/inspection they should change pads at 40% and that to me is overkill for street use.
Next level is the groove in the pads.
Third is the sensor warning. If you blow past those and disable the warning then lets agree you are really going past the safety margin set by both manufacturers. I get different people have different levels of maintenance but come on people, these are Porsches.
Also does depend on who is driving, that was another good point. I'm not the only one who drives my cars so I have that to consider that others might not. But the joke about mechanics having the worst maintained cars has some truth to it and if you need that post to know how to turn off the warning, you should probably think hard about doing it.
My old 911 only has wear sensors on the inner pads of each caliper. My BMW X5 only has wear sensors on one pad on one wheel in the front and one wheel in the rear. I consider those both safe, as well as the suggestions above. I've even driven cars without any wear sensors at all, except for the metal tang that scrapes the rotor.
Safety is important, but at some point it's important to consider the safety level of everything else in the system (like other cars) before making one thing perfect.
I realize people who fix cars professionally have other factors to consider here.
I expect that anyone who knows what a wear sensor is, and knows how to circumvent it is sufficiently in-tune with their vehicle that it is safe to do.
Exactly. I neither the most conservative or riskiest person on here when it comes to machines. I calculate all my driving and mechanical risks and part of it comes from both motorcycle and flight training (and wrenching on those machines as well.) We are not recommending this to people who are bringing their car to the shop to do their brake pads and I believe it is only a safety issue for completely clueless drivers, not the enthusiasts on this forum who check their brakes 4 or more times per year and will jump on fixing any issue that comes up.
My further thoughts:
1. The brake sensors are way conservative. The last set I changed I had put more than 3k miles since the sensor tripped and there was at least another 3-5k miles left on the thinnest pad after that.
2. The brakes will start making a horrendous noise if you start getting the edge of the pad backing scraping the rotor before you lose much braking capacity - should you be unfortunate enough to have a stuck cylinder or another issue right at the end of the pad life. My experience with stuck calipers is that it tends to happen much more often with fresh pads and not at the end of pad life when the cylinder is further extended. Most of us would probably detect that anyways since we are not the average genpop fools.
3. It is common practice in the enthusiast community to remove all of them. I can't count how many 911 drivers I have seen who have done this to save time/effort/money at the track.
03-18-2018, 03:14 PM
Use an old sensor wire for future testing of circuit
