GM 1-ton brake cylinders

[Yeret]

I've been doing some reading on improving the stopping power in my 1500 and a common thing that pops up is swapping the OEM rear brake cylinders with GM 1-ton cylinders. Has anyone here done this swap? I've read that this swap significantly improves rear and overall braking but I'm just curious to read some more testimonials. Is this a simple swap and go job or does the works need some fiddling with to make it work?

My rear drums and shoes are pretty much at their service limits and need to be replaced which I have no problem with but I'm curious about swapping these large cylinders in while I'm at it.

 

[dudeman2009]

Personally, I wouldn't even bother. About 70% of braking is done with the fronts without a trailer attached, and it's easy to lockup the rears even on dry pavement if the ABS doesn't work. If you put a trailer on the back it evens out a little to about 60/40 front and rear percentages.

IMO all putting bigger cylinders in the back is useless as whatever gains you have will be at best half of what is actually gained in the cylinder. If you double your rear braking power, unloaded you're only doubling that last 30%.

You WILL notice it, but thats only because you changed the braking characteristics, the rears start to grab sooner than before, but the fronts will always be a majority of the stopping power.

Honestly, if you want better braking performance, get more aggressive semi-metallic pads for the front. Anything rated heavy duty or for towing. They also make different types of shoes for the rear.

I cant remember which years the GM 1tons will swap into nicely, some require modifications. Its too much work to gerry rig something that really won't change a whole lot when I can get almost the same change by just putting different pads/shoes on and not having to modify anything.

The real question is, why do you want different braking characteristics? There might be another way to reach your goal.

 

[Yeret]

Good stuff to note, thanks for the input.

Basically, I'm just looking for improved braking power without spending craptons of cash. I've spent plenty of time looking to make my truck GO faster but never really took a serious look at making my truck STOP faster. As we all know, brakes can be your and/or someone else's life so I'm just curious as to what can be done to make a 5,000 pound truck stop faster, especially for those of use that tend to drive, oh, "spirited."

 

[dudeman2009]

If you only weigh 5000lbs, don't even bother with the GM cylinders. My truck hasn't weighed less than 5500lbs since I bought it. I average about 6000lbs, now plus the weight of a 5.2l in the bed, and I can stop on a dime. I haven't services the drums at all since I bought it 4 years ago. I just put a nice set or rotors and heavy duty pads on the front and I can lock those things up on dry pavement. Even when I pull my cargo trailer full of stuff I feel like I stop in a respectable amount of time.

 

[SHOOT2KILL]

Personally, I wouldn't even bother. About 70% of braking is done with the fronts without a trailer attached, and it's easy to lockup the rears even on dry pavement if the ABS doesn't work. If you put a trailer on the back it evens out a little to about 60/40 front and rear percentages.

IMO all putting bigger cylinders in the back is useless as whatever gains you have will be at best half of what is actually gained in the cylinder. If you double your rear braking power, unloaded you're only doubling that last 30%.

You WILL notice it, but thats only because you changed the braking characteristics, the rears start to grab sooner than before, but the fronts will always be a majority of the stopping power.

Honestly, if you want better braking performance, get more aggressive semi-metallic pads for the front. Anything rated heavy duty or for towing. They also make different types of shoes for the rear.

I cant remember which years the GM 1tons will swap into nicely, some require modifications. Its too much work to gerry rig something that really won't change a whole lot when I can get almost the same change by just putting different pads/shoes on and not having to modify anything.

The real question is, why do you want different braking characteristics? There might be another way to reach your goal.

I believe my 1998 chevy cc drw had drum brakes...My 2002 chevy cc drw had rear discs...My personal preference after 1,000,000+ miles under my belt driving/towing duallys, were the drums on the 4 pre 2002 duallys I owned...Every few thousand miles I would crawl under the truck and "SPOON UP" the rear brake adjusters...

 

[hamyscj]

I just put these on my truck.

Funny story, I bought them for my 98.5 diesel about 12 years ago. Sold the truck and bought my current 99. Just needed to do them 2 weeks ago. Found them on the shelf where I put them 12 years ago and put them in.

From what I remember, they increased the volume of brake fluid slightly. The OE bore is 13/16 and these were 7/8. They were a Napa part number 37337

The only reason I replaced them was mine were leaking. I did not notice any braking improvement after installing them but I needed them anyway so that's why I did it. Not sure I'd spend the time on them if I didn't need them. I know guys are saying that they are the bomb but I wonder if it's like taking some aspirin and drinking a glass of water. Headache goes away and we assume the aspirin did the trick when really all we needed was a glass of water. Maybe the act of bleeding the nasty old brake fluid out is all the truck needs.

Anyway, they installed with no mods on my 2500 D60 rear.

Hope this helps