It's time for a set on new disc brake pads and was wondering if O.E.M. pads were bonded or riveted. Were they semi-matallic or cerramic or who knows what.

What do most of you purchase and where? NAPA, Auto Zone, Advance, Crown, Quadratec, etc?

 

I'm also getting ready for a brake job. So far I'm planning to go with Napa premium rotors and adaptive one pads.

Good Luck with your search.

 

I buy riveted brakes. In my opinion glue and heat don't get along all that well.
I bought NAPA brakes, the better ones, when I bought my current XJ about 2 years ago and they are still good. It did take a while to break them in but well worth it.

 

If you have a choice, go with rivetted. Heat gets bled off of the pads better, and they take a bit longer to fade than bonded.

I've also had bonding fail - it's supposed to be heat-resistant, but there are occasional problems. Rivets don't care about heat - the only way they'll really "fail" is if they get hot enough to melt (!) or the pad cracks and works out from underneath the rivet heat (nothing you can do about that - but proper run-in does help prevent it.)

Brands? I prefer Bendix or Raybestos (effectively tied for first,) with Wagner running a close second. They're available in the aftermarket, and cost about two-thirds what OEM usually does.

Even if the OEM pads are bonded (not generally with light trucks, but about even odds with pax vehicles,) I'll replace them with rivetted for the reasons given.

If the rotors are wavy, but still otherwise within spec, you're better off having them turned and putting the new pads on them. Heat is a big issue with brake friction parts - and replacing both pads and rotors can cause "heat checking" in the rotors, even if they're run in properly.

The thumb rule for run-in is no hard stops that can't be avoided for about 500 miles. When I do my brakes, I'll do the first drives myself - I'll go on the freeway around 0100 or so (when there's nearly no traffic,) and smoothly stop a couple of times from 60MPH. Don't feather the brakes, don't stamp on the brakes - just a smooth stop that takes 500-600 yards or so to effect.

Why? Because fresh friction material hasn't been heated yet, and will generate gas - "outgassing" the first few times it's heated. It typically takes 300-500 miles of regular service before the friction material stops outgassing routinely and gets properly bedded - it can happen rather more quickly if you do like I did above, since outgassing tends to decline sharply after the first couple of heat cycles (having control over initial heating of the brake friction goes a long way toward brake longevity!)

"Fade" is caused by overheating which causes a recurrence of outgassing - you get a layer of pressurised hot gas between the friction surface and the rotor surface, which forces the friction material away from the rotor. "Heat checking" is caused by the friction material being forced away from the rotor and suddenly clamping back down, which causes "hot spots" in the rotor. If you get into the job and see blue checks on the rotor, replace it outright! You can't "turn away" heat checking, it's usually through, causes stress risers, and the easiest way to salvage the part is melt it down and start over...

Brakes are not something you should play with - you'd be amazed at how much effort I put into the job (moreso if you see me doing it, since it doesn't look like I'm doing anything special...)

 

Hi Jon:

Thanks for the very informative reply RE: front brake pads for the XJ. I've looked over some of your projects and realize that you have been working with the XJ much longer than I have. Keep up the good work and I'll probably be seeing you around here again.

Webb

 

Can't say I care for riveted brake shoes and pads. No matter the brand I have seen the material crack between the rivets. I have heard rivets can become loose.... But never seen it happen myself.

If you are having brake fading issues you either need a better pad/shoe or use a drilled rotor. During normal use either riveted or bonded will be fine.


If you have a modified rig with large tires and/or you tow the only universal advise I can give is don't skimp on the quality of parts. IMO EBC makes great quality pads and rotors. I run their product on my dirt bike and Camaro both applications are for pure performance. Since I have stock tires on my xj I just have O'reilley specials on there. I have converted to disk rear brakes. If I need better stopping power I will upgrade to EBC all around and drilled rotors on the front.

 

That was a very good brake reply from 5-90. All of his facts are quite correct. Well done.

The original pads were bonded. And, yes, riveted have a reputation for being a bit better according to some, but are more difficult to find. The possibility of cracking the pad material at the rivets is a real one. I've seen it, but it is more common for brake shoes to do that after some wear has occurred.

The brand name pads like Raybestos and the others are often a good way to go. I've had good luck with Auto Zone's better pads. I never buy the cheapest pads available. Brake parts are something that never should be cheapened.

I don't know about the rest of you, but I've had fade issues with the XJs on occasion well into the life of the pads. It's usually from repeated hard braking in city driving like going down multiple grades. The best solution I've found is to install slotted rotors. The slotted or drilled & slotted rotors combat fade by allowing the gasses somewhere to go during braking.

Also, an FYI. Make sure to check your caliper sliders carefully. They tend to corrode and bind especially in corrosion prone areas. Clean and lube them well, if not substituting new ones, before replacing them in the caliper with the new pads on your spindle.

 

Very correct on the slider rails - I'll usually hit them with a wire wheel, then use a round-end steel rod (I have a couple) to burnish dry graphite into the surface - best lubricant I've found for that sort of thing. Oils and greases collect dust, adding friction dust to oil/grease ends up creating grinding paste. Bad juju.

I've been thinking of slotted rotors for my XJ, but they're a a pain to find for the 88. I may end up having rotors slotted or drilled myself - I don't like having sharp edges on rotors, since they function at both heat risers and stress risers (the edges of slots and drilled holes should be rounded and blended into the upper surface, and a ball mill should be used to mill the slots for slotted rotors. Sharp corners, paradoxically, will actually decrease the dissipation of heat, and that leads to increased internal stresses in the part. Sharp discontinuities in the metal also function as stress collection points - so it's a double whammy when heat is involved.

(It's like body repair - if a structural member is left with a crease, replace it outright. A crease in a metal panel is like the broken line on an envelope that says "Tear Here.")