Reality Check: Brake Pad Wear, Normal or Not?

Dan Sarandrea (Phila)

Waitin' On Parts...
What's the sense of the forum regarding brake pad wear relative to front vs rear?

Here's why I am asking. I disassembled my brakes today to repaint the caliper brackets. I could not help but notice that the front brake pads are still very very meaty, as in you would have a hard time telling them from brand new thickness. On the other hand, the rear brake pads were very well worn, probably at 25% remaining friction material thickness.

I will post actual dimensions later for reference.

Items of note:
1. All pads have the same mileage on them, approx. 4,500 miles.
2. All pads show even wear, inner vs outer.
3. Brake pedal is firm.
4. The car "feels" like it does more of its braking at the rear, based on how much nose dive happens in various braking situations.
5. The front tires can be locked up with the needed pedal pressure.
6. Brake pedal travel seems a bit longer lately, which now makes sense looking at how much the rears are worn.
7. No signs of system external leakage.
8. Just a hint of pedal pulsation on lighter braking which is probably a little bit of rotor warpage; spin testing all four corners shows that the left front is probably the one that's mildly warped.
 
I find this wear pattern surprising - mine are generally much more uniform fore and aft.

I'm not sure what to make of the observation that the car feels as if is braking more from the rear because that's a bit subjective - but that's not how I think any of mine feel.

Have you done anything to the suspension that might reduce forward weight transfer when braking? I've known master cylinders to stick in such a way that they keep pressure on the pads, but that's always been enough to completely lock the wheels on the affected circuit.
 
In case you aren't aware, the rear pads have a lot less material vs. the front when new. At least half the thickness of material.
 
Front: 17mm thick
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Rear: 10mm thick
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As noted, the rear pad material is much thinner when new so the only real comparison is how much thinner the rear pads are from stock thickness. Guess you will have to do another 4,500 with new pads front and rear and check back again. My experience with Fiats is that they are pretty easy on pads front and rear (Xs and spiders) with normal driving. Your observations seem to indicate all is normal with your brakes.
 
:)

Anytime, I try and help out when and where I can!

My experience is that the X1/9 is pretty easy on brakes as well (mostly because I never use them, they only slow you down!)
 
I find this wear pattern surprising - mine are generally much more uniform fore and aft.

I'm not sure what to make of the observation that the car feels as if is braking more from the rear because that's a bit subjective - but that's not how I think any of mine feel.

Have you done anything to the suspension that might reduce forward weight transfer when braking? I've known master cylinders to stick in such a way that they keep pressure on the pads, but that's always been enough to completely lock the wheels on the affected circuit.

Myron figured it out for me.....friction material thickness of the rears starts out being a lot less than the front.
 
Hmm. We just bought a complete set (front and rear) from Bayless and I was VERY surprised at how small the rear's were (but after installing them in the caliper there is NO way they could have been any thicker and still fit).

After Driving both my yellow X and my wife's blue X I notice her car stop's (Max, right at tire lock up breaking) her car stop's faster with a lot less front tire lock up. But both car's will lock up the front first.

(just for reference other than bleeding the only break work we have done on either car is her rear pad's and rotors)
 
Hmm. We just bought a complete set (front and rear) from Bayless and I was VERY surprised at how small the rear's were (but after installing them in the caliper there is NO way they could have been any thicker and still fit).

I'm using the basic MWB pads at all four corners of my car. The car stops well, with some brake dust - nothing major though. They're very quiet as well. They did have shims on them, but I had to remove them as they wouldn't fit into the caliper! I called MWB, and they recommended pulling them off.

These pads will probably last my lifetime!! :)
 
These pads will probably last my lifetime!! :)[/QUOTE]

Yep, you can just about bet on that!!
I have owned my '78 1300 X for 18 years now - (wow, hard to believe!)
I replaced all brake pads soon after buying the car, thinking like you that the rears were (appeared anyway) much more worn than the fronts!
When the new pads arrived, the first thing that was apparent was that the new rear pads were so much thinner than the new fronts! When then comparing with the old pads, it became clear that was normal, and the "old pads" actually were still good!
So, having bought the new pads, I thought "bugger it, I have paid for them", so I fitted them into my X.
That was about 16 years ago (15,000 miles maybe :rolleyes:) and they still look almost new!

cheers, IanL - NZ
 
With my older Volvo (1970) you could wear down the front (ATE) pads, then transfer them to the rear for a few more years.
 
OK that makes much more sense, thanks Myron!

Here are my measurements of the friction material only, not the backing plate+friction material:
RR: 4.35/4/33 10 - 4.35 = 5.65
LR: 4.32/4.37 " = 5.68
RF: 10.89/10.94 17-10.89 = 6.11
LF: 10.76/10.71 " = 6.24

Using myronx19's specs, your numbers say the pads are wearing Evenly. My thinking is: The Front pads are Thicker, but Softer material, to prevent Premature Lock Up. The Rears are Harder because the engine weight is going to help keep traction, making them harder to stop, without Downshifting. I must agree. These cars seem to Brake most from the rear. Anyone that's REALLY Driven these cars knows full well. You STAB the Brake pedal at Any speed, the Fronts Lock Up and you're just along for the ride until you come to your senses, back off the pedal and STEER your way out of trouble.
 
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Using myronx19's specs, your numbers say the pads are wearing Evenly. My thinking is: The Front pads are Thicker, but Softer material, to prevent Premature Lock Up. The Rears are Harder because the engine weight is going to help keep traction, making them harder to stop, without Downshifting. I must agree. These cars seem to Brake most from the rear. Anyone that's REALLY Driven these cars knows full well. You STAB the Brake pedal at Any speed, the Fronts Lock Up and you're just along for the ride until you come to your senses, back off the pedal and STEER your way out of trouble.

Actually, I don't think the formulation of the pad is any different front to rear - what really affects the bias (and therefore wear) is the piston size. The rears are smaller, so less clamp force = essentially less wear. Also, the weight transfers forward when you brake, so the fronts do a lot more work. The rears just keep the car going straight IMHO. My race car had four front calipers all the way around, and immediately I had to adjust the brake bias to have more front vs. rear (only thing that changed was I had four front pads and calipers), as the piston is larger in the front caliper.

My 2006 Pontiac Vibe has 300K kms on it now (187K miles), and it still has the original rear drums and shoes! The rears do nothing :) heh, I can squeeze another 16K miles out of the rears.. how is that even possible!??! hehe.
 
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