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Old 05-26-2022, 11:55 AM   #1
Factory Guy
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Re: brakes?

Looks like I have found my answer. It involves a new Master Cylinder, from a later model SUV, as they displace more Brake fluid when the pedal is depressed. Apparently the Disc's on these Trucks are pretty darn good its the Master that is the weak link.

More details to come.
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Old 05-26-2022, 08:32 PM   #2
LT7A
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Re: brakes?

Quote:
Originally Posted by Factory Guy View Post
Looks like I have found my answer. It involves a new Master Cylinder, from a later model SUV, as they displace more Brake fluid when the pedal is depressed. Apparently the Disc's on these Trucks are pretty darn good its the Master that is the weak link.

More details to come.
Cool! Keep us posted.
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Old 05-26-2022, 10:45 PM   #3
Willowrun
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Re: brakes?

Quote:
Originally Posted by Factory Guy View Post
Looks like I have found my answer. It involves a new Master Cylinder, from a later model SUV, as they displace more Brake fluid when the pedal is depressed. Apparently the Disc's on these Trucks are pretty darn good its the Master that is the weak link.

More details to come.
I would agree with this in theory at least. I had a '99 2500 Suburban 4x4 for several years that I towed with that I felt was severely under braked at the time. Brakes only lasting 30-40,000 miles, soft pedal, pulsating, etc. After owning several newer generation truck with my newest now a '17 2500 the brakes are leaps and bounds better than my '99.

So with that, unless the upgrade is coming from something much newer, I don't think there was much improvement in braking from the square bodies through '99.
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Old 05-27-2022, 12:53 AM   #4
kwmech
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Re: brakes?

If everything is put together and adjusted correctly you should have no issues stopping the truck. I'm still running 4 wheel drum on my 68 3/4 ton haul and tow occasionally without any issues. The hauling includes a complete pallet of block now and then. Then back for about 20-30 sacks of concrete or cement. The square bodies had even better brakes with the 13'' drums and disc brakes.
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Old 05-27-2022, 08:57 AM   #5
SCOTI
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Re: brakes?

Quote:
Originally Posted by Factory Guy View Post
Looks like I have found my answer. It involves a new Master Cylinder, from a later model SUV, as they displace more Brake fluid when the pedal is depressed. Apparently the Disc's on these Trucks are pretty darn good its the Master that is the weak link.

More details to come.
Quote:
Originally Posted by kwmech View Post
If everything is put together and adjusted correctly you should have no issues stopping the truck. I'm still running 4 wheel drum on my 68 3/4 ton haul and tow occasionally without any issues. The hauling includes a complete pallet of block now and then. Then back for about 20-30 sacks of concrete or cement. The square bodies had even better brakes with the 13'' drums and disc brakes.
Having "no problems stopping the truck" & 'improving' the brakes are two different things. Improvement is also subjective w/o testing & validation.

If the brakes stop the truck w/o issue, technically they work & we call that a win. But what distance did it take to perform the task? The ability to complete the same task better in this case would likely be a shorter distance. Stopping the the same vehicle/weight in a shorter distance would be an improvement if it's repeatable.

I can see increased hydraulic pressure helping to some degree but there is going to be a limit as the existing surface area of the brakes will become the point of diminishing returns.
Increasing hydraulic pressure along w/the contact surface area that pressure is applied to? I can see THIS making a bigger difference.

What Matt did in that linked video was increase the surface contact area by changing over easily swapped parts. He did not change or improve/increase the hydraulic pressure.

In his case w/his Tahoe, the rotor size was increased. A larger rotor has more contact area for friction. It's possible the caliper piston size also increased since he swapped the matched calipers for the slightly larger rotor. It's also possible the piston area is not larger; we'd have to research that. On a similar GM format (Camaro vs Corvette brakes), the parts can similarly be easily swapped over & the same caliper can be used on the 12" LS1 rotor as well as the base C5/6 12.9" rotor or you can increase the piston area of the caliper w/a different caliper.

Like I mentioned initially, I have not seen any later model parts that can easily be swapped over to these earlier chassis trucks. That being said, I'm always open to listen to the ideas of others.

You could probably increase the hydraulic pressure applied on a vacuum brake set-up by simply swapping to a manual brake master cylinder of the same era as they have smaller bore sizing which would yield higher line pressure w/everything else being unchanged. That's also a common swap on the car platforms when dialing in brake performance changes.
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Last edited by SCOTI; 05-31-2022 at 08:10 AM.
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