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Old 05-26-2015, 01:37 PM   #1
1972CST
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Upgrade?

Getting ready to replace the master cylinder and upgrade to ss flex brake hoses so my question is should I go back with a stock replacement MC or is there an "upgrade" that I should consider?

1972 K5 , disc front, drum rear. Mostly stock, running 33" tires.

Thanks!
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Old 05-26-2015, 01:45 PM   #2
cleszkie
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Re: Upgrade?

I would consider upgrading to a dual diaphragm and master cylinder combo used on the 3/4 and 1 ton trucks of this era. There are threads on this subject that you can do a search for. I did this years ago, and it was a big improvement over the stock 1/2 ton single diaphragm/master cylinder combo.

Many people have also gone to hydro boost systems, which are also pretty easy to install, and offer the best brake assist oout there. Also threads on this board about that. Good luck.
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Old 05-26-2015, 05:09 PM   #3
Chulisohombre
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Re: Upgrade?

I'm still using the stock One with no problems. I'm not sure if it will happen to you but I've heard the bigger diaphragm on the one ton master not pushing enough volume and giving a spongy feeling to the brakes. I have disk front and rear now and still Have the same master and booster. You may have to Modify your pushrod from the brake pedal. Not sure if it has the same brake lines or not.
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72 3/4 ton blazer. 5 inch lift on 35 inch tires. 355 corvette engine with crane roller rockers, rv cam, edelbrock carb and intake with one inch spacer. Thrush Headers with flowmaster 40 duels. 4speed sm465 manual. 4 wheel disk brakes with Inboarded rear shock prerunner style mounts and shocks.
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Old 05-26-2015, 05:46 PM   #4
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Re: Upgrade?

I bet you'll be just fine with a new stock replacement and the new lines. The new lines alone will help get rid of any sponginess. I've done some upgrades in the past that I now look back and question whether I actually gained anything.

Are you having any present problems with the the system?
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Old 05-26-2015, 05:51 PM   #5
partsstoreguy
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Re: Upgrade?

this is a question i have been debating in my mind also. i have 1 ton axles, disc brakes all the way around, and will be running 40 inch toyo mt radials. I have really been looking at the hydroboost but haven't talked to anyone who is running them to see their thoughts.
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Old 05-27-2015, 03:32 AM   #6
Chulisohombre
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Re: Upgrade?

With the one ton and disks I'm betting you are at the limits on the stock master. Hydro boost will give you the strongest pressure possible out of any brake system that came on a Chevy truck. I've heard a lot of people say once they upgraded to the bigger brakes hb helped a lot with the extra pressure needed to push the calipers. I have disk all around and still use the stock system. I just gutted the prop valve and took out the rear residual valve so front and back get full pressure.
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Old 05-27-2015, 09:45 AM   #7
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Re: Upgrade?

Quote:
Originally Posted by Yukon Jack View Post
I bet you'll be just fine with a new stock replacement and the new lines. The new lines alone will help get rid of any sponginess. I've done some upgrades in the past that I now look back and question whether I actually gained anything.

Are you having any present problems with the the system?
The biggest problem I have with the current MC is brake fluid leaking from under the cap. Its a reman unit that is only a few years old but it has leaked since day one. I should have swapped it immediately but it never happened.

I hope the SS braided hoses help to firm up the pedal also. I figured if I was going into the system for the hose upgrade, I might as well fix the MC leak. I will probably just swap the reman unit for another since it has a lifetime warranty.

Thanks for the input guys!
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