Brake Repair: Slotted/Drilled Rotors worth the cost?

[swissarmychainsaw]

My k10 Suburban is under-braked!

I'm replacing the master cyclinder, and brake lines, and considering disks as well.
Replacements are $25, or you can get drilled and slotted for 65-95$ (each)

Anyone done it? Worth the trouble and expense?

Thanks!
Nick

[bdiamond]

You get what you pay for. The baer rotors are pricey but well worth the money. The cheapy ones on ebay are softer than the box they come in and will warp up and wear horribly if you use any kind of decent pad.

[SkinnyG]

Try a better brake pad, like a Hawk HP+ if one is available for your truck.

[SCOTI]

Drilled & slotted OE rotors are for looks only.

The more surface area, the more friction contact there is, the more stopping power available.

Larger diameter helps w/more leverage & surface area.
Better brake pads help to increase the friction.
Larger caliper/ greater piston area equal large distribution area of force applied.

[Just call me Sean]

Originally Posted by SCOTI

Drilled & slotted OE rotors are for looks only.

The more surface area, the more friction contact there is, the more stopping power available.

I'm not sure if anybody saw this, doesn't seem like it. Drilled and slotted stock sized rotors will show reduced braking efficiency because there is now less friction area for the pads to contact. The only way to gain with them is to increase rotor diameter.

[swissarmychainsaw]

Interesting...

I guess the problem I'm trying to address is that on about three occasions I have "cooked" my brakes. Off-road going down a very long and steep hill(s). Meaning they heated up until they were literally smoking. Another time I lost the pedal (lucky I was off the hill by then) and just waited until they cooled off.

I'm looking to fix that.
Thought the drilled and slotted might help dissipate heat a little better.

(I'm also replacing the rubber lines and Master)

[SCOTI]

What size truck?
What size (dia & width) current brakes?
What size loads?

[swissarmychainsaw]

Originally Posted by SCOTI

What size truck?
What size (dia & width) current brakes?
What size loads?

K10 Suburban 1973, as far as I know it's stock rotor size.
I'll measure it when I get home this evening.

Loads are: Family of three with camping gear. Not exactly a "truckload".

thanks for the responses!
Nick

[SCOTI]

Originally Posted by swissarmychainsaw

K10 Suburban 1973, as far as I know it's stock rotor size.
I'll measure it when I get home this evening.

Loads are: Family of three with camping gear. Not exactly a "truckload".

thanks for the responses!
Nick

So that truck would have 1.25" x 12" rotors w/D52 calipers. K = 4x4 right? Does someone even make a drilled/slotted 4x4 rotor?

[DBLSPRT68]

I bought my BMW with drilled/slotted rotors on the front. I warped one some how, and can not find a shop that will turn them.. I just bought new regular rotors. Look into what the guys have posted before me, that sounds better to me also.

[Tucson38]

I'm under the impression that the slotted rotors were more efficient because the slots allowed for cooling and the release of the gases and dust created by braking. But I don't really know.

[SCOTI]

Originally Posted by Tucson38

I'm under the impression that the slotted rotors were more efficient because the slots allowed for cooling and the release of the gases and dust created by braking. But I don't really know.

Slotted rotors have less stress related failures (cracking) vs drilled rotors. In a racing application you prob will notice a diff. In a street environment, not so much because normal street use just doesn't heat-up/gas off like a race car would.

It's rare to see a braking comparison where the solid OE rotors were swapped for drilled/slotted version of the same size w/no other changes (same pads & calipers) w/a notable difference.

Larger diameter rotors for better leverage (& heat disappation) & bigger calipers w/greater clamping (more consistent contact area) would work better.

[wilkin250r]

I would LOVE to get bigger rotors, and I spent a couple hours searching for a kit about a year ago, couldn't find anything. I've got 40" tires, I'd really like to have a little extra leverage from the brakes to counteract the extra leverage from the larger tires.

I saw some homemade jobs, and my fab skills aren't bad, but I don't trust them to anything that critical.

I've seen big-brake kits for lots of sports cars, but have never been able to find anything for our trucks other than OEM-style replacement.

[1977cheyenne_C10]

Have you tried Brake perfomance.com? The have dimple and slotted rotors with lifetime warranty and i believe they come with brake pads.I never tried them but seems good for dimpled rotors rather than getting drill rotors.

[86c20]

how long are these hills? i mean damn you are cooking the brakes going down the hills off road at what speed? i pull trailers with my c 20 and never but maybe once have i cooked the brakes. and that was with 20k at 45 down hill when a dummy pulled out last min. how are you braking? just holding the peddle down? if so thats wrong. need to roll brake alittle harded till you slow down a bit lower then you want and reless them. same way we do in semis. works for them works for you. also better pads. i just put in wagner power stops not what i wanted but so far are 10x better then the cheap autofail pads i ran. and they where 28 bucks at rockauto.

[willett]

You can't turn slotted/ drilled rotors.

I hate the damn things

[SCOTI]

I guess my point was the drilled/slotted rotors are always advertised as an improvement but seldom is there testing to prove the benefits.

[dieseldawg142]

Originally Posted by SCOTI

I guess my point was the drilled/slotted rotors are always advertised as an improvement but seldom is there testing to prove the benefits.

so true, dont have them on my square, but i have drilled rotors on my '90 K1500, made not one bit of difference. i got much better results using ceramic type pads, seems like the hotter they get, the better they grab. put some on the wifey's envoy as well, feels better than the stockers

i'm with 86c20, just HOW big are these hills? when we go camping we're loaded at 15 thousand & i have the "smasher", a 10% grade hill for 9 or 10 miles just down the road from me & i've never had the brakes on my crew "cook" or fade, use your gears to keep your speed under control.
i did the brakes on my crew 5yrs ago, everything new, lines, calipers, rotors, drums, springs, etc, front disc, rear drum, stock set-up but used "premium" parts. stops pretty impressive for a 4 ton truck.

[smashingchuck]

Originally Posted by SCOTI

I guess my point was the drilled/slotted rotors are always advertised as an improvement but seldom is there testing to prove the benefits.

I agree, and usually they just look out of place. Raybestous sells some nice quality slotted/drilled rotors through rockauto. Best bang for the buck if you're going for the "look".

[donut]

I was just appreciating the education, not had a problem with the brakes that couldn't be corrected with driving habits, so didn't know a thing about upgraded components.

I questioned riding of the brakes, but when you learned on 4 wheel drum brakes and know what it's like for them to fade out before the bottom of the hill. And by fade, that's both feet on a hard brake pedal and nothing happening.

[79Betty]

I took my slotted n drilled k10 rotors to o'reillu's n turned em. Turned out fine.

[franken]

I think the rear drums will fade in the OPs case so a rear disk swap may be in order. Autocross folks say the rear disks don't change normal performance much but drums fade.

BTW, braking is about 75% front and 25% rear, which explains why front disks appeared 1st. That said I've driven stuff w/ bad brakes and while not fun, its less bad when the rears don't work.

Maybe a semimetalic pad in the front as well?
If you're fourwheeling I doubt the drilled slotted will get air to cool either.

[homemade87]

Rear drum brakes are pretty efficient vs disc. The problem with drum is they do not get rid of the heat very well under heavy long braking . The drums will fade away like the op had happen. The disc can get rid of the heat much more efficiently. That's the biggest argument to change to disc. As for the drilled and slotted, what they do is get rid of the gasses under the brake pad under heavy braking. When you heat something that fast it will build gasses. Under normal braking you will not notice any difference and that's what most of us experience.That why most of use have said I seen no difference. Under panic , hard or long hard braking when you build the most heat is where you see the most improvement . If you can get rid of the gasses under the pad you will have more clamping power.

As for are they worth it. If you just do reg driving then no. You will not see any difference. If you do hauling or any heavy braking ( performance) you will benefit from drilled or slotted or both. They will dissipate the heat and gasses for better pad to rotor contact.

From the problem you have posted my vote would be yes. I do believe you would benefit from the drilled/slotted disc.

Note, I have had drilled and slotted turned.

[cadillac_al]

I dunno, it seems if you are using that much brakes then you may be in too high a gear. If you are in low range and low gear and still cooking the brakes then you have reached their limits and could use an upgrade.

[68Timber]

To me it sounds like a good excuse to upgrade to 3/4 ton or 1 ton axles and get the bigger brakes that come with them.