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13"x3.5" Rear Drums (1 Ton)

AgDieseler

AgDieseler

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13\"x3.5\" Rear Drums (1 Ton)

I just finished putting on some really big rear brakes. For us subbie owners, it's an easy conversion.

Supposing you have all the brake hardware (drums, backing plates, and rebuild stuff) there are only a few details to be aware of.

1)Make sure that you have the suburban parking brake cables designed for 13"x2.5" drums. LMC sells some great American made cables for $20 a pop.
2)The setup is large enough that the backing plates can be assembled off the vehicle, then installed as a complete assembly.
3)New wheel studs make the conversion Kwality.
4)Make sure you find a shop that can PRESS in the studs. Pounding them in takes a while.
5)Don't wait until 5:45 on a Saturday night to look for a place to press them in!

After I put these on, the brake bias is definately towards the rear. I mean, this beast stops!

I may have left out some stuff, so feel free to email me with any questions.

[email protected]
 
Re: 13\"x3.5\" Rear Drums (1 Ton)

so they are just wider right? would i get the same brakes by throwing a 1-ton 14 bolt FF under my sub?
 
Re: 13\"x3.5\" Rear Drums (1 Ton)

Yes...........

I'll say this tho - a 3/4 ton 14BFF stopped my K5 incredibly well compared to a 12 bolt setup. Can't imagine the one ton brakes being THAT much better than 3/4 ton............but haven't experienced it so can't say for sure. /forums/images/graemlins/burb.gif
 
Re: 13\"x3.5\" Rear Drums (1 Ton)

I can't speak to the improvement from 13"x2.5"s, but I'm coming from having 11"x2"s. I've noticed a big difference.
 
Re: 13\"x3.5\" Rear Drums (1 Ton)

What did you put the brakes on? Did you have a 3/4 ton FF or SF axle to begin with? What are the bigger brakes off of? I have the 3/4 ton FF and I want to put bigger brakes too. I woundering if the 1 ton FF brakes fit. Is this what you did?
 
Re: 13\"x3.5\" Rear Drums (1 Ton)

You could use the 1-ton rear end complete, but you'd need to change the spring perches (40.5" vs 42.5"). Now a 14FF from a 3/4-ton CUCV (73-76) also has these 13x3.5" brakes.

AGdiesler:

In changing the brake cables... what exactly was different? I've seen backing plates with a round hole for the cable, and others with a triangular hole. Also the cables vary if the trucks has both cables up one side, or one up each frame rail. Just curious what you had and what you changed to.
 
Re: 13\"x3.5\" Rear Drums (1 Ton)

Not that it is any help to the conversion, but my Brother just bought a '98 3/4 ton Sub with the 454, and the HD suspension. It came factory with a 14 bolt ff with the 13 inch brakes. It is the new style ff with the drums that slide over the hubs from outside like a sf axle.
 
Re: 13\"x3.5\" Rear Drums (1 Ton)

Those are a nice setup. To use them on our older trucks, you need the hubs and drums for sure. I think the backing plates are the same however.
 
Re: 13\"x3.5\" Rear Drums (1 Ton)

The backing plates are the post '85 style with small holes. That's for the press in cable rather than the bolt on triangle mount.

In '85, they changed the cables so that they ran on the driver side. It is a less problematic design.

The 13x2.5 cables have longer springs for the inside of the drums. That is just to make sure that your p-brake engages properly.
 
Re: 13\"x3.5\" Rear Drums (1 Ton)

True, the triangle shaped holes use 2 bolts to hold the cable to the backing plates. These also use 2 equal length cables which fasten to the mounts at the forward rear spring hanger brackets.

The push in type cables use the smaller round hole. And yes, the passenger side is longer, going over the pinion and to the driver side to fasten to a bracket along with the driver side cable.

But the year split for the different cables is '82 and '83, not '85.
'82 and older used the equal length bolt on cables, while the '83 and newer used the push in type cables. /forums/images/graemlins/wink.gif
 
Re: 13\"x3.5\" Rear Drums (1 Ton)

/forums/images/graemlins/wink.gif /forums/images/graemlins/thumb.gif
 
Re: 13\"x3.5\" Rear Drums (1 Ton)

the only problem I have wiht my 13 inch brakes is new drums are going to cost me more then finishing the rear disc swap. I suppose I could risk it on a set of used drums, if I'm lucky enough to find them at a junkyard... otherwise brakeshops want 250/each for them, and autozone wanted $400 for them...

I figgure I bought the brackets, just need to get the discs ( about $30/each,) the calipers (20-30 each for front calipers, no P-brake) the brake lines, ( no clue ) new studs ( no clue) and about a days worth of time to tear it down, and re assemble it. one of these days...

-Rich
 
Re: 13\"x3.5\" Rear Drums (1 Ton)

I've got a pair of drums and backing plates from an M1008 that had low, low miles on them. There's even brand new shoes on them, too. Drums are very thick and do not need to be turned down as it appears someone already did it. E-brake cables for these backing plates are the push-in type. Are you interested in these instead of paying out the a$$ for new drums? /forums/images/graemlins/wink.gif
 
Re: 13\"x3.5\" Rear Drums (1 Ton)

Hey Wes, do you have a set of push-in style 11 inch backing plates that will work on my 14 ff? I just need the backing plates.
 
Re: 13\"x3.5\" Rear Drums (1 Ton)

Yes! As a matter of fact, I do! And yes, they fit the 11" drums also.
I got them from another member here, for $40 for the pair. I will sell them for the same but you need to pay the shipping, which shouldnt be too high since I package them in the smallest box possible.
 
Re: 13\"x3.5\" Rear Drums (1 Ton)

I'm interested if you still have them... I'll PM you for details and whatnot,

-Rich
 
Re: 13\"x3.5\" Rear Drums (1 Ton)

another quick note: if you put on the larger Brake drums, you really should also get the larger Masterbrake cylender. believe you me, there is a difference, ( I'll ahve to get pictures of my monsterous MBC next to the `little' Standard MBC. ) the cylinder itself isn't too much bigger, ( larger diameter, and longer throw I think) but it helps that much more, as well as having about twice as big a fluid resevior.

-Rich
 
Re: 13\"x3.5\" Rear Drums (1 Ton)

i bought a complete set of 13x3.5 rear drums and backing plates for my 79 k20 but the parking brake cables that are on my 79 now would not work with them . i found this out after i removed mine and tryed to put them on . so i didnt put them on . but i do want too .. so what do i need to do to make them work?
 
Re: 13\"x3.5\" Rear Drums (1 Ton)

Sounds like you got the 83-up backing plates and are trying to use them with 82-older cables.

The only fix I can forsee is to get the right backing plates, or change over to the newer cable assembly (might require everything up to the pedal /forums/images/graemlins/blush.gif )
 
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