Technical Brake Pad Wear Sensor

[SBQ]

2013 Ducato 130 MultiJet done about 60,000 miles. Curious on others how they went about changing the brake pads. Lately i've been seeing random alerts on the display cluster saying "Change Brake Pads". This message appears on odd occasion, say once a week, just after starting the engine. I found this odd as recently I have checked the front disc brakes when I was doing the front strut mounts and it showed plenty of meat left.

In older vehicles, usually the low brake pad wear alerts the driver when you hear a scraping metal to metal sound as the brake pad rubs on the rotor. Do the Fiat Ducatos have this or they rely purely on electronic brake sensing of the pad wear?

Another question, we don't replace the rotors as they do with ceramic brake pad / system?

 

[the green vanper]

Hello,

In my van the both front and rear pads were in theory changed just before I've purchased the van. Of course could not be 100% sure about it, but there was some garbage left suggesting it was done. And after the checkup I could confirm it was. The problem is you can only check the front and rear disc pads is without disassembling the rear. And the rear system contains both disc and drum:

However there was this warning on all the time. I'm not sure if I saw a written warning (like in your case), or there was only a light on.

I couldn't figure out how the wear is controlled. I decided I will take the rear apart to check the drum condition and I discovered that the ABS sensor, which is magnetic, was totally covered with the abrasive dust from the pads and the dust was touching the ABS ring. I've cleaned all the dust from the sensor and the ring, reassembled everything and the warning was no longer there.

Of course this could have been pure coincidence, but the brake pads having no visible wear sensor I assume it was the cause.

 

[SBQ]

Hello,

In my van the both front and rear pads were in theory changed just before I've purchased the van. Of course could not be 100% sure about it, but there was some garbage left suggesting it was done. And after the checkup I could confirm it was. The problem is you can only check the front and rear disc pads is without disassembling the rear. And the rear system contains both disc and drum:

View attachment 459178

However there was this warning on all the time. I'm not sure if I saw a written warning (like in your case), or there was only a light on.

I couldn't figure out how the wear is controlled. I decided I will take the rear apart to check the drum condition and I discovered that the ABS sensor, which is magnetic, was totally covered with the abrasive dust from the pads and the dust was touching the ABS ring. I've cleaned all the dust from the sensor and the ring, reassembled everything and the warning was no longer there.

Of course this could have been pure coincidence, but the brake pads having no visible wear sensor I assume it was the cause.

"The problem is you can only check the front and rear disc pads is without disassembling the rear. And the rear system contains both disc and drum:"

If I recall correctly, the inner hub brake shoes are for the handbrake or emergency brake lever? At random after starting the engine, the display says the brake pad change alert, then goes away. Then after a weeks use or so, the message comes back. What I would like to see is as the pads wear down, then the alert will become more persistent to a point that it just stays on or it will nag me every time I start the engine. I don't feel like taking off all the wheels to look closer at the inside pads. But judging by the front outside pads, peeking through the alloy wheels, I would estimate more than 5mm thickness.

What year is your Fiat Ducato?

 

[the green vanper]

It's a 2011 x250 heavy chassis.

Yes, the drum is for the handbrake only. So the warning is not about the actual wear of the shoes.

In my case the warning was triggered by the dust collected by the ABS magnetic sensor touching the ABS ring, which was closing the electrical circuit. And it was not definitely the dust from the drum shoes, but from the disc pads (mostly the inner one I suppose).

I've found a photo of how it looked. You can even see the signs of the sensor sliding over the dust on the ring:

As far as I remember, the sensor is not reachable with the drum/disc on. But can be totally mistaken here.

That's the right side with the wheel removed:

It was a drity job, so I was not making any other photos during the proces. Try looking on youtube, the shoes adjustment is tricky, so it is likely there are some tutorials on the replacement process.

I can see on the internet both front and rear disc pads have wear sensors. One of the set has a wire + connector.

I have not changed a single piece on the van on both wheels, all I did was removing, cleaning and refitting and the warning problem disappeared. It took me almost 6 hours for the first wheel and like 2 and a half for the second one start to finish (including preparation and cleaning afterwards). I'm not a mechanic and it was the first time since ages I was touching the drum brakes.

And as I wrote before, I can't be sure if it was the warning message on the display, or the warning light on the speedo / tacho. I have some photos of the dash, but only when the van was stationnary, so the handbrake could have been engaged. It was before I've purchased MES, so have not checked for ABS related errors before / after this job.

 

[SBQ]

Just an update, i'm currently on travels and the change brake pad wear sensor has become more of a nag which appears nearly every time I do a drive. So when I get back to home base, I will need to investigate this further.

 

[brokendonkey]

you can find out which one it is by looping out the wire in the plug in the wheel arch.

 

[SBQ]

you can find out which one it is by looping out the wire in the plug in the wheel arch.

My OBDII reader finds nothing. I mean it does not say which wheel is with the intermittent wire sensor.

Another observation during strong rainy weather, the 'check brake pad' notification does not appear. Even after repeat braking on highway driving. So something may point to me that a brake pad sensor may be faulty or simply is worn down.

Hope to look later next week.

 

[brokendonkey]

if you loop it out then it will take that sensor out of the circuit, So you know if that sensor is at fault.

 

[jackwhoo]

Obd 2 does not cover brake pad wear

 

[SBQ]

Obd 2 does not cover brake pad wear

I read somewhere the 'check transmission' alert was tied into with the brake sensor alert but you're right, I may be looking at 2 separate issues.

Had a drive the other day an no check brake pad sensor coming up. Crappy weather lately so have no taken the tires off (still need to get a lift jack)

 

[Communicator]

My only experience with brake wear sensors was many years ago on a Talbot Express with discs on the front wheels only. When a warning light illuminated, I managed to stop in a safe location. A quick inspection revealed adequate pad thickness on both front wheels, so I disconnected the sensor connection on both wheels. When the pads were subsequently replaced, it was quite evident that the sensing wire on one pad was exposed far to close to the braking surface.

 

[SBQ]

My only experience with brake wear sensors was many years ago on a Talbot Express with discs on the front wheels only. When a warning light illuminated, I managed to stop in a safe location. A quick inspection revealed adequate pad thickness on both front wheels, so I disconnected the sensor connection on both wheels. When the pads were subsequently replaced, it was quite evident that the sensing wire on one pad was exposed far to close to the braking surface.

That's the part I don't understand. The brake pads are original to the van and this brake sensor nag has been appearing for the past 2 years. When I had new tires put on I had the tire shop inspect all the brake pads. He said they had plentiful of pad thickness left. Last year I had both front struts taken out to replace the strut tower mount. At that time I again, inspected the front brake pads and plentiful of thickness.

Makes me wonder as it's usually the front pads that do most of the braking (which I have not checked the rear pads). Usually the front brakes does 80% of the braking?

 

[SBQ]

OK just finished changing all the brake pads. The rear wheels do not the sensor wire The front wheels BOTH sides have the sensor wire (inner brake pad). I guess later years the sensor pads were installed on ALL 4 wheels but 2013, my Ducato only has them on the front.

The culprit for the wear sensor was the 1 pad on the driver side that wore down the embedded wire. Inner pad on the rear wheel had the most wear.

May have to re-bleed the brakes again as my dad working the brake pedal while I was opening / closing the bleed nipple, may have introduced air in the line (not keeping the foot down before I closed the value). Will see over a few days as i've the ABS unit may have some air in the line that over time can get purged out.

 

[brokendonkey]

Glad you got to the bottom of it.

 

[SBQ]

Glad you got to the bottom of it.

Yes, so sometimes it's best to "Let the Computer Decide"

But 1 of the rear pads had the lowest wear (far lower than the front pads). I guess that's why in later Ducato models, they included the brake pad sensors on all wheels.

Now i'm letting the van sit for few days to see if the air bubbles have settled. I will need to re-assess if the sponge like braking is the brake pads trying to bed in on the rotors or I really go some air in the line.

 

[The Panda Nut]

computers can not go wrong go wong go wrong go wring go wrong gowrong go wrong