286bhp

iTrader: (1)

Hi guys,

At my last HPDE, I had my front-left inside brake pad (Ferodo DS2500) wear all the way to the backing plate. Looking at the amount of pad material on the other front pads, and I wonder if I experienced pad failure on that one pad.

Am I seeing normal differences in pad wear or did I experience a failure?










My last 4 HPDE days were at clockwise tracks. I know this puts more wear on the front left tire. Maybe it also puts more wear on the front left brake pads?

You can also see that in general my inside pads are more worn than the outside ones - is this unusual?

Thanks!

PVD04

iTrader: (23)

I'd say that is probably normal. My inside pads always wear faster than the outside. Also, if you were on a clockwise track and staying on the brakes as you started to turn you would wear the left brakes faster. It also appears all your other pads were nearly completely worn, so it's entirely reasonable that you wore the left inside pad down to the backing plate.

-Paul

286bhp

iTrader: (1)

For street use, I presume that when the center groove is no longer visible it is time to change the pads. (Like the way my front-right inside pad looks.) Is the purpose of the groove to be an end-of-life indicator?

PVD04

iTrader: (23)

I would guess so. I usually go by the rule that when the pad material is the same thickness as the backing it's time to replace. That would only be for street driving. I won't start a track day with more than 50% wear.

-Paul

286bhp

iTrader: (1)

Ok, thanks!

Smike

iTrader: (8)

Those are not track pads either. The MOT is only 1000F. Not high enough for HPDE. Looks more like they melted off. Or at the least hurried the wear rate.

286bhp

iTrader: (1)

You may be right... I got about 7 days out of the pads and from the 3rd day on I was experiencing some pad transfer during my events.

xtnct

iTrader: (33)

Appears to be normal on the Brembos, no matter what the pad. So a search. Here is one thread as an example for you:
https://www.evolutionm.net/forums/sh...d.php?t=370172

The pad crumbling on your pics is due to overheating (ie, getting your pads outside their designated temp range)

For your reference, here is what my pad wear looks like (DTC-60's), also the drivers side (left) on a clockwise track.

286bhp

iTrader: (1)

Thanks xtnct.

I did see some other threads about inside wearing quicker than the outside, however I was just surprised by the difference in thickness. So, I decided to post some picts .

286bhp

iTrader: (1)

I take it that the left-side pad is the inside pad?

Do you swap the pad sides mid-season to extend the life of your pads?

Finally, are those broken dust boots around the top most pistons? Any performance problems related to the broken dust boots?

xtnct

iTrader: (33)

Picture is of the drivers side (left) caliper on a clockwise track. The more worn pad is the inside ofcourse. Also note more wear at the top of the pad (despite the caliper having a design to fight that ie, smaller piston size up top)

My plan was to swap between events (thinking I was going to get 2-3 weekends out of a set), but this pic is only after 1 weekend. So, I'll have to rotate the pads after one day of use next time....


If you look closer, the dust boots are cracked around every piston. That is what happens with race pads and the temps generated. The caliper also is no longer red either, but I assume you know that already. The dust boots just keep dirt out away from the seals, they have nothing to do with performance. You just have to be aware to rebuild the calipers with new seals more often.

286bhp

iTrader: (1)

By performance I was thinking about stuck pistons rather than braking distances. Are you more likely to get a stuck piston with the broken boots? How frequently do you rebuild the calipers (and what does it cost?)?

xtnct

iTrader: (33)

Think of what the dust boot is there for. Why (and how) would a broken dust boot make a piston get stuck? Most calipers that seize are floating ones and not fixed ones. If a fixed one does seize (Brembos are fixed BTW), it is usually from some kind of issues internal to the caliper (like too much water in fluid leading to rust) and not enough use to keep things going back and forth. Now, the dust boot could play a role in having a piston seize if you do not use your car. If enough water & metallic grime get in between the seal and the dust boot, that could eventually lead to having a piston seize (rust) if you hardly ever use the brakes.

In most cases, broken boots lead to faster wear of the seals and possible piston damage. Think of what the seal does. It prevents the brake fluid from squirting out past the pistons. If you damage the seal (by having grime, salt or whatever rip it, or eat away at the rubber, or damage the smooth piston surface that leads to seal damage), then you will basically notice brake fluid disappear over time or you will get an instant failure with brake fluid squirt out past a piston onto the rotor while trying to stop (had that happen on another car).

Anyway, race calipers do not even have dust boots. When you should rebuild the calipers depends on the combination of what you use the car for, how many miles between rebuilds, your road conditions and other factors. Check with some race teams or ask Brembo what they suggest on their race calipers that have no boots. With the way I use my car, I end up doing it every 2 years or so, but I inspect very thoroughly a few times a year. I check for any brake fluid leaks, brake fluid residue on piston, on inside caliper & rotor & pads, keep a constant eye on brake fluid level (but note level goes down as your pads wear also) and check for any odd piston abrasions and any abnormal accumulation of moist dirt & gunk near the pistons (that is a sign that you have a slow leak). Similar to the gunk you see on old engines with slow oil leaks in the engine. If it is not dry enough to where you can just blow the dust away with a puff to see condition of piston and surrounding area, you probably need to rebuild. Also checking the amount of play in the piston is another indicator of a seal condition.

Don't know the labor costs as I do it myself. I think the seals are around $100. Not sure of the pistons cost if you need them. There are threads with that info already so just do some more searching

286bhp

iTrader: (1)

xtnct, you are a wealth of information! Many thanks!

SoCal Rally

You can use titanium backing plates to help reduce heat transfer from the pads into the caliper pistons and piston seals.

xtnct - that seems like a lot of wear for a dedicated race pad for 2 days of use ... $300 is a lot to spend for new front pads every track/race weekend ... what type of track days/racing are you doing? What type of rotors, fluid and tires are you using? Any other factors that you can think of that can explain that amount of pad wear?