Upgrading brakes on 84 K10

[Ewhitaker0020]

What's the easiest/best way to upgrade my brakes? I have a fairly stock 84 K10 with a 305 engine. I'm worried about my brakes overheating and failing while hauling a trailer or firewood. I don't know if that's likely to happen because I'm not overloading the truck, but I would like to be able to have extra assurance that I'll be able to stop the truck.



How can I upgrade the brakes without getting into a big mess or big money? Do I change the calipers? Or the rotors?

 

[1987 GMC Jimmy]

It depends on how much you want to spend. The gold standard for brake upgrades is going with rear discs, but I don’t think that would ever be necessary even hauling the box full volume, high mass or keeping the trailers at or below 5K pounds gross. If you hauled a 5000 pound trailer, I think the 305 would be the biggest loser in that case, not the brakes as much. I daily an L69 HO 305, essentially what you have, and I can’t ever see it pulling 2.5 tons in it’s mostly stock form.

Nah, what I would recommend is when you go to do your new pads and shoes is that you don’t skimp there. Organic pads are tantalizing because they’re cheap, and they do the job, don’t kill your rotors/drums, and they’re fairly quiet, but their performance leaves plenty to be desired. I would weigh the differences between ceramic and semi-metallic pads. I went with ceramic everything on another vehicle, and they perform very well. I like them over semi-metallics because even though they perform arguably the best, it gives me anxiety to think about my rotors and drums being more rapidly chewed up by the semi-metal on metal.

Two, make sure you turn your rotors and drums when you do the job, and that they’re within spec thickness. That way you have the greatest contact surface possible. And three, flush your brakes if you haven’t done so already. Unless the PO was Good Housekeeping‘s Car Owner of the Year, I’ll bet that fluid is nasty and moisture laden, which is quite problematic.

 

[Ewhitaker0020]

It depends on how much you want to spend. The gold standard for brake upgrades is going with rear discs, but I don’t think that would ever be necessary even hauling the box full volume, high mass or keeping the trailers at or below 5K pounds gross. If you hauled a 5000 pound trailer, I think the 305 would be the biggest loser in that case, not the brakes as much. I daily an L69 HO 305, essentially what you have, and I can’t ever see it pulling 2.5 tons in it’s mostly stock form.

Nah, what I would recommend is when you go to do your new pads and shoes is that you don’t skimp there. Organic pads are tantalizing because they’re cheap, and they do the job, don’t kill your rotors/drums, and they’re fairly quiet, but their performance leaves plenty to be desired. I would weigh the differences between ceramic and semi-metallic pads. I went with ceramic everything on another vehicle, and they perform very well. I like them over semi-metallics because even though they perform arguably the best, it gives me anxiety to think about my rotors and drums being more rapidly chewed up by the semi-metal on metal.

Two, make sure you turn your rotors and drums when you do the job, and that they’re within spec thickness. That way you have the greatest contact surface possible. And three, flush your brakes if you haven’t done so already. Unless the PO was Good Housekeeping‘s Car Owner of the Year, I’ll bet that fluid is nasty and moisture laden, which is quite problematic.

Thanks for the tips. I recently changed my brake pads with acdelco OE semi-metallic pads. But, I skimped and didn't resurface the heavily scored rotors because I don't have the know how to take apart the hubs to get the rotor off. Since then I've found a shop that will resurface them on the truck if they're not too bad. I'm thinking about taking it back and having them resurface the rotors and change the pads again.

I don't know why I'm worrying about it so much on this vehicle. I guess it's just because it's older. Maybe I'll go with some ceramic pads on this next brake change.

I did see a kit online to change the back brakes to disc. But man, it's expensive.

 

[1987 GMC Jimmy]

That might be worth considering. It boils down to you looking at how much interface between the pads and rotors is occurring and deciding whether or not you’re satisfied with it. The fronts do approximately 70% of the braking, which is why it’s been the industry standard for 55-ish years to have discs in the front and the poorer performing, more fade-prone, and more lock-prone drums and shoes in the back. Plus, it’s very simple (and cheap) to just run a cable back there to mechanically engage the parking brake.

It is expensive. There’s an old thread on here where they talk about using Chevy Astro calipers and rotors, but I don’t know what they came up with on the proportioning valve besides bypassing and chunking it since it’s unnecessary to meter fluid with four wheel disc brakes. And then rigging the e-brake. I don’t see a world where four wheel discs are necessary on a half tonner, except if you just hate working on drum brakes or you’re drag racing an SWB.

With all due respect, I do agree you’re worrying a little too much about it, at least with regard to engine cooling and the brakes. A seventy or more year old truck lacks a lot of even rudimentary technology and can benefit from certain modernizations, but the OEM systems on these trucks are pretty ironclad without being overcomplicated as they would be later on. The simplicity is the Hail Mary of an older vehicle, and if it wears out, I’ll happily maintain the status quo. I’ll take the few horses a thermal clutch fan leeches in exchange for not having to worry about fan relays, thermostatic controls, a wiring harness, and two motors.

 

[HotRodPC]

I'd be thinking about looking into Wilwood if I was worried about it. Crossdrilled rotors cool quicker and Wilwood Calipers are usually dual piston and give more clamping force on the rotor not to mention more even clamping at both ends and center of your pad rather than just the center.

 

[bucket]

The factory K10 brakes, imho, are very good for what the truck should be able to handle. Assuming they are working properly of course. Any decent trailer load should have it's own set of brakes.

 

[Grit dog]

Thanks for the tips. I recently changed my brake pads with acdelco OE semi-metallic pads. But, I skimped and didn't resurface the heavily scored rotors because I don't have the know how to take apart the hubs to get the rotor off. Since then I've found a shop that will resurface them on the truck if they're not too bad. I'm thinking about taking it back and having them resurface the rotors and change the pads again.

If the old rotors are grooved, the pads have already taken the shape of the rotor profile. If you get them turned, either be careful at first as the new used pads wont bite the whole rotor until you wear them down. Not really safe until you get the pads flat again, beware. And your brake pads won't really be 100% ever after going through getting overheated on the high spots. I've let the rotors grind down grooved pads before but not recommending it....

 

[RoryH19]

Other than the above mentioned, I've heard hydroboost is a good option.
They were factory available on 1/2 tons if equipped with a diesel. 1 tons had them standard.

I pulled one from a c30 recently to install in my 82 k5.
No concerns with factory vacuum assist brakes but I wanted an upgrade too.