Brake pad’s sensors hole.

[szvook]

Need to replace the front brake pads and the Porterfield R4-S pads (AP847 for SA brakes) I received have the holes for the sensors closer to the backing plate on two pads and two pads have the holes towards the center of the pads. Shouldn’t all four holes be closer to the backing plate? With the holes towards the center of the pads, the length of the sensor wires is too short and the sensors will not be locked in place in the pads. Plus the holes in the middle of the pad will shorten the pad surface life before the pad sensors are triggered. Do all four pads need to have the holes closer to the backing plate, for the four sensors? The below image shows the location on the hole in the middle of the two pads I got and two pads with hole closer to the backing plate.

 

[gsxr]

Steve, I've seen this on multiple brands for this particular brake pad. I don't understand why two would be in the middle of the pad, it makes no sense. And, it's not possible to install the sensors for the 'middle' hole location. What I did was drill a hole in the proper location so you can install all 4 sensors. Or, you can not use 2 sensors... if you pick that option, have the sensors on the inboard pads only (these typically wear slightly faster than the outboard pads).

 

[TerryA]

@szvook,
Steve, my theory is to sell more brake pads. You might want to contact Porterfield. They are in Costa Mesa and ask about their quality control.

The other option is put the pads w/ the holes closer to the backing plate on the inside per Dave’s observation that the inside pads wear faster.

My first thought is to contact Porterfield directly. I bought my pads directly from them in Costa Mesa. I’m interested in what your solution is I’m probably right behind you in needing new pads.

Good Luck

 

[gsxr]

I recall @omegabenz having the same problem 15+ years ago. I suspect they are drilling 2 holes in the center of the pad on purpose, but I can't fathom what the reason is.

On a related note, the late R129 which have these Brembo 334mm calipers as standard equipment from the factory, only use 2 sensors, not 4. So, this is not an issue for vehicles which had these pads from the factory. We are putting them on an older (124) chassis which normally has 4 sensors. Porterfield is likely to tell you to pound sand.

 

[szvook]

@gsxr @TerryA Thank you for the insight and feedback. I have been communicating with Wendy Charlier the General Manager at Porterfield and she mentioned that the pads are spec’d out from the manufacturer to have 2 holes close to the backing plate and 2 holes further out. Poterfield’s only thought was that the Mercedes engineers wanted to alert you when you were halfway through the pads and then again when they needed to be replaced. In the past, I did not have the pads handy to look them over before having them installed, but this time I did. I will use two sensors on the inboard pads and just leave the other two pads with holes in the middle alone.

Btw, this whole thing started when I got new R4-S pads and all four pads had holes in the middle of the pads. I got a hold of Porterfield to let them know and they promptly sent me new pads, as the first ones were already installed. The second set had two holes in center and two hole closer to the backing plates, which made me question the design. So I will run the first set without sensors and visually inspect the pads for now. The upside to this, I got a free set of pads and will install them with sensors when the time comes.

 

[szvook]

Btw, I asked Porterfield if there’s a chance to request the pads with the holes by the backing plates only. Let’s see what they’ll say.

 

[szvook]

Ok, Porterfield said yes, but it may delay the order a week or so. No price change and just request for all 4 sensors holes be drilled near the backing plate

 

[szvook]

The rear AP603 pads are ok as is.