Thanks for your help

 

If this is a version of the usual make/break wire circuit then putting a jumper across the connector after removing and discarding the worn sensor should bypass the warning light. Of course you'd have no wear sensor either. The plastic slug presumably just has a loop of copper wire embedded in it which breaks circuit when it wears through. The dash light then goes on.

 

I unintentionally miss spoke when I suggested the pad wear sensors could be had for $ 20. The most recent sensors I have purchased where for a Porsche. I assumed the parts for a modern Porsche were as costly as any so that's where I got the $20 figure which is accurate for The Porsche sensors.Must admit I'm impressed with the $70 cost for the Jaguar version considering the simplicity of a pad wear sensor. My appologies for misleading the group on that point.

 

I can confirm that jumping the sensor wires removes the low pad warning state. I did my rear pads and hadn't ordered a new sensor. Cut the old end off the sensor, stripped the wires and twisted them...heat shrink and voila.

Happy with Porterfield pads btw

 

2010 onwards have the 2 sensor wires, as others have mentioned. The light can come on for more than one reason...

1. obviously worn wires that are telling us to replace the pads
2. a faulty wire
3. one or both sensor wires have come 'loose', or altogether disengaged from where they plug in due to - a shop not putting them back where they go, or even a strong automatic car-wash can get them loose enough to send off the low brake warning (which for me has happened twice so far)

 

Pad sensors are there so non-car people know when to get their brake pads changed.

For car people, you will notice when your pads need replacing as part of your routine maintenance, when the pads start to get low you will install better pads that don't dust and don't eat the rotors, and you will replace the pads before the sensor touches the rotor, so your sensors will be reusable forever, and you won't get soaked for $70/sensor.

 

Spot on!
When I replaced all four sets of pads a bit over a year ago I could not get the blasted rear wear sensor to stay in it's little slot (it had not been triggered, the rear pads were still near new but were the horribly dusty stock pads so I replaced them anyway). So I simply used a couple of zip ties to secure it up out of the way.
For many reasons I regularly remove the wheels (tyre swap, calliper painting etc), and whenever I do I check out the brake pad wear and condition.

 

It's a little tricky, but if it's not staying in, it's because you aren't seating the mounting pin all the way into the spring clip before inserting the spring clip into the brake pad grove.

If you do it right, you can't pull it out without breaking it. If you do it wrong, it just pops out with the slightest touch.

 

Hi Gents
I am new member here and I have 2013 Jaguar XF
same issue brake massage low rear brake pad appear in my data information center (dash board) and car run only 14000 miles only.
so I ordered new pad but do I need to order the sensor as well??
thanks

 

Yes - the pad sensor is a consumable part. When it is triggered it means the wire end has been worn through (intentionally). So yes - you need a new one. Seem to run around $50 or so if you find a dealer who sells online. Note you should check rotors as well - 14k is perhaps early, but split views whether rotors need to be replaced with each set of pads, or each couple of times. I'd suggest measuring them and checking against spec to see what's needed in your specific case.

 

Here's my two cents' worth. I understand from the Jaguar dealership parts counterperson that the brake wear sensors are quite brittle and almost always broken when they're removed to replace the pads. So, most likely, yours broke when the pad was replaced. The list price for a Jaguar OEM sensor is around $80+. That being said, I had my rear pads replaced twice and the fronts replaced once without replacing the sensors. But I did tell the mechanic to be very careful not to break the sensors because they're expensive (unlike BMW, Mercedes, etc. sensors, which are usually under $20 each).


As to pricing, I've seen sensors for Jaguar XF's under $22 at Rockauto and Autopartswarehouse but they're not OEM. I've also seen Jaguar OEM sensors for $65 shipped at Partsgeek.com.


If anyone has experience with a particular brand of aftermarket sensor, please let us know what your experience has been.

 

Just want to add some first-hand knowledge and demystify what some mechanic blows up your you-know-what as I always do my own brakes because I want that done right. I have 2 XF's that I have changed the front and rear pads already on both of them, so I know about these cars.

The sensors are not brittle unless the car is really really old. No XF is really really old at this point, so that's BS.

If they break the sensors, they are idiots because they are very easy to take out without damaging unless you try to remove the calipers before removing the sensors.

The sensor is literally a loop of a wire that when it rubs on the brake discs it breaks the connection. So there's no big computer thingy in there that needs to be compatible with the car. Any aftermarket one will work. In a pinch, you could just strip the wires and connect them together.

The sensors should never need to be replaced by anyone following normal routine inspection methods on their car. If the pads are changed before the light comes on, you can always reuse them unless you don't know what you're doing and break them on remove.

 

Thanks, that is useful information. When the time comes to replace my front pads, I think I'll just order an aftermarket sensor with the pads and have it on hand just in case the original one breaks. Cheap insurance to prevent a return trip to the mechanic.

 

So, for us "non car people", what do you believe the minimum pad thickness should be before replacement? I ask, because my rear sensor lit up when there was still 4mm left on the pad. And, BTW, the OEM pads will just about wear the rear rotor to the minimum specified thickness (24mm) after one set of pads.

 

Same my rear brake thicness about 3-4mm.and light up.

 

Well, cutting through the hyperbole about "car guys" not having their wear sensors cut, I looked up the specs for minimum pad thickness for my XFR rear brake. It is specified to be 2 mm, which is a good bit thinner that the 4mm thickness where my brake wear sensor had the wire cut.

I would contend that both car guys and non car guys would expect the wear sensor to open after the pads reached the minimum specified thickness and not before, but that is apparently not the case.

A little math might be in order:
If we know the rear new pad nominal thickness is 10.8 mm, and the sensor is cut by 4mm, then to prevent sensor cut, we should probably try to change brakes when the pad thickness is about 5.8 mm because we would not ant to be mic-ing it every month, so we would effectively use 5 mm of pad. (10.8mm-5.8mm)
If we use the brakes to the 4mm thickness when the warning comes on, we destroy the sensors. In this case, we use 6.8mm of pad

The ratio of 5/6.8 is about 75% of the pad. So, assuming we have someone else change the brakes, and they use good pads and either face or replace the rotors, we are talking about $350.00 to $500.00 for a brake job minimum. If we change the pad at 75% of the life, the excess cost is about ($350. / .75)- $350. which is the about $115.00 wasted, which is the cost of replacement sensors.

And, good luck on getting a $350.00 brake job, so I see absolutely no reason to worry about changing the pads early to save the sensors.

 

Car guys don't pay people to change their pads.

Your advice is good for the average Joe, and housewife.

 

Well, I always change mine myself, too, but it still takes time. And the parts cost $350. if you change the rear rotors, like Jag recommends.

 

If you guys want to run aftermarket pads that don't have sensors, or even if you don't want to pay for replacement sensors, it is possible to turn off the pad wear sensing system, although a dealer won't do it for you.

 

When/where does Jag recommend to replace the rotor?