The Stovebolt Site Forums The Parking Lot Big Bolts Disc brakes for 1.5, and 2 ton trucks

ehh Philippe, you're on it. this is now page 13.

He’s referring to Stovebolt.com

After reading this & other disc brake conversions my brain hurts & am now more confused then ever how to do a front axle 1 ton conversion for a 1 ton panel. Unless someone has a condensed version of how to do it??? Or is there a way to change it over to a 6 bolt disc brake set up??? Mean while I figured I'd google it & see what popped up. Anybody heard of these folks or have used their kits???? https://www.tsmmfg.net/chevy-gmc-8-lug-truck-complete-front-disc-brake-kit-1847.html Thanks......joe

Turns out the P-30 stuff doesn't really fit (overall axle width) for the 8 lug single wheels trucks. Didn't know that from the start.

This thread did result in a good solution for the 2 ton with 5/10 lugs.

For 1.5 ton, it looks like adapters exist to convert 8 lug to 5 lug, so a f450 or 4500 front axle may be a good option.
https://www.airbagit.com/mobile/Category.aspx?id=1591

I wanted to add this to the mix..

I mainly found this information as it pertains to my 1968 C50 but it may be usefully for our other fellow members. This information came from user rkn463 over at the chevy 67-72 forum. http://67-72chevytrucks.com/vboard/showthread.php?t=704713

It seems that he discovered that the disc brake spindles from an 1989 C60 box truck could be adapted to the 67-72 medium duty F050 5000lbs front axle. rkn463's plan was to transfer 1968 truck body onto the 1989 chassis. To have the wheels still tucked under the fender, he chose to adapt the new spindles to the older, narrower axle. See below for more details.

"A few months back my attention came back around to the truck. As much as I like the 327 in the 68 this will be a working truck and the 366 from the 89 is a better option. Plus it already has all of the accessories like power steering/hydroboost pump ans A/C compressor already mounted. Further measuring looks like the hydroboost will bolt up to the 68. That front axle thing is killing me so I get to looking at the SPIDs on both trucks, they both have an F050 (5000lb) front axle, it is just that the 89 is 6 inches too wide. More measuring and it looks like the 89 spindles might fit the 68 axle. I researched on the internet and found this:

http://www.stemco.com/f/qbin/STEMCO_Kaiser_2013.pdf

I found that the bore in the older axle needed to be enlarged by .0070 and I could put the 89 spindles on the 68 axle. That was the deciding factor, I'd just go ahead and use the entire 89 frame and drivetrain in the 68 but with a narrower axle.

Rather than pull apart the 68, I pulled the front axle from the 70 GMC frame that I had acquired and took it to a local machine shop to have it bored out. I also ordered a set of kingpins online. This was December 2015. After a few weeks of waiting to get that axle back I pulled the 89 in the shop and removed the brakes, spindles and axle. Things got held up at the machine shop and I finally got the 70 front axle back in early March 2016. I cleaned it up, repainted it and reinstalled the 70 axle in the 89 truck with the 89 spindles. It went smooth except that the stops on the steering linkage did not line up with the stops on the axle so I had to drill and tap a new hole."


I'm not sure if this helps those with older models but I hope this helps someone.

Grigg,

Would you mind helping me out - I cannot find NAPA # 262-1016 online. Will the guy behind the counter be able to look this up?

Grigg probably knows a source.

Here are some "hits" from a Google search. Maybe one of them sell that part?

Added later: I could not find a seller for that part - sorry.

The source is NAPA, that's their part number.
I just called and ordered a kit myself, 70 some dollars and no shipping if willing to wait a few weeks for the normal NAPA trucks to bring it. As of today, 6-25-19 They have one in Atlanta, Memphis, Oklahoma, LA, and Utah among other places I assume, and 5 kits at the manufacturer's distribution warehouse.
It is still a good part number and when those are gone more will be available. My parts guy at NAPA recalled that part number was (in past years) a very common kit, even before looking it up in the computer.

Thanks Grigg! Perhaps NAPAs website isn't user friendly =P

I'm green when it comes to big bolt trucks and am looking to put disc brakes on my 1930 1 1/2 ton. Am I correct in my initial reading that this thread covers later models? If so, can anyone point me in the right direction?
Thanks.

I also am interested to know if anyone has any experience with the website Joe refers to. I looked at the website and it appears that they are using 78-85 Monte Carlo calipers rather than pickup calipers. I wonder it those could handle the heat dissapation required of a bigger vehicle like my nearly always loaded 8800lb 1-ton,

It probably has to do with size. I used C1500 calipers and had to do some grinding to make 16 inch wheels fit.

Most of the heat capacity is in the rotor/drum. The lining is a relatively good insulator compared to the iron of the rotor, even semi and full metallic linings. The swept area of the rotor, that area the width of the pad x the circumference of the rotor, is one of the main determining factors in brake rating. The size of the caliper determines the clamping force and thus the deceleration rate that can be applied to a given gross weight. If you can clamp tighter, you can stop faster. If you have big rotors, you have more time available before overheating and you have more leverage against the turning wheel.

Sweepleader, I have no doubt that what you say is correct; It's just that I have brake heating problems on the front as it is and boiling brake fluid makes the brakes really erratic. Think of repeated stops from 60 mph for the lights on Bangerter Hiway in Salt Lake City. I need to do something soon as the drums are pretty thin. Rears are OK.

I did not mean that you should not use discs, only that the caliper does not determine the heat capacity of the brake, the rotor does for the most part. If the drums are not doing it for you, for sure, switch to discs. I put discs on my '62 K10 and they are great. I was able to swap from a '72 K10, they are easily 3x the brakes as far as heat goes. When a disc heats up it expands toward the caliper, not away from the shoes as a drum does.

I also am interested to know if anyone has any experience with the website Joe refers to. I looked at the website and it appears that they are using 78-85 Monte Carlo calipers rather than pickup calipers. I wonder it those could handle the heat dissapation required of a bigger vehicle like my nearly always loaded 8800lb 1-ton,[/quote]

Good afternoon,

The calipers we use for this kit, are actually from a K20.

Reminder,

This thread is about using P-30 parts to adapt disc brakes.

It is not a catch all thread for any sort of disc brake conversion. If it were it'd be less helpful and very hard to search and make sense of. (not that it's easy keeping you head wrapped around just the P-30 details and possibilities)

Please start a new thread or find an existing thread to discuss various other disc brake kits or conversions.