Best Performing C/K Series Stock GM Brake System ???

[79 silverado]

Long story short, I'm thinking of re-doing the brakes on a project and keeping it for the long haul.

Is there a brake system off of any particular year of the c/k series that would perform best or have advantages over any other?

As part of the re-vamp I would have no issue with buying everything new from the master cylinder/vacuum booster/lines/prop valve/rotors/calipers/hoses/drums/shoes/etc. Most of these parts are either worn, old, or have something wrong with them to begin with.

Having said that, what would be the best performing set-up to use (ie which year) to go into a c10 with a 12bolt rear? I am concerned with stopping ability in heavy traffic and durability, do not care about bling factor which is why I am asking about stock configurations rather than the wilwood type stuff that actually has lower piston surface area than the stock stuff. It'll all be behind factory wheels anyways so nobody will see it. For the same reason, would be looking to just leave drums in the rear.

Is there an advantage to going to an 80s setup with the aluminum master cylinder over the cast iron one? (which I hear rumored is more friendly to occasional driving since the piston doesn't stick and blow out the seal)? Would the HD 1.25" rotors and such be worth the effort to upgrade to?

Is there a larger vacuum booster that would give any advantage over original?

I am primarily a newbie when it comes to brake system upgrades and the like so thoughts welcomed and appreciated.

[Tdubbyount]

If you want more clamping force all together I'd go with a hydroboost system. It boosts using hydraulic pressure from your power steering pump. I'm pretty sure it came stock on all the diesels. I'm not sure if it uses a different master cylinder than the vac systems. You will need a different power steering pump because they run different pressures. It will be more expensive than going vacuum, but gives you some pretty dang good brakes.

[Desert1957]

Originally Posted by Tdubbyount

If you want more clamping force all together I'd go with a hydroboost system. It boosts using hydraulic pressure from your power steering pump. I'm pretty sure it came stock on all the diesels. I'm not sure if it uses a different master cylinder than the vac systems. You will need a different power steering pump because they run different pressures. It will be more expensive than going vacuum, but gives you some pretty dang good brakes.

"Hydro-Boost" system has no effect on brake "Clamping Force" it takes the place of a Vacuum booster for reduced pedal effort.

Its is uses on Diesels and HD one ton's.

Master Cylinder applies ALL brake pressure.

Desert

[INSIDIOUS '86]

Originally Posted by Desert1957

"Hydro-Boost" system has no effect on brake "Clamping Force" it takes the place of a Vacuum booster for reduced pedal effort.

Its is uses on Diesels and HD one ton's.

Master Cylinder applies ALL brake pressure.

Desert

Idk about that myself. The assist force is greatly increased and from what I've driven on some trucks the brakes are much stronger than vacuum booster style.

Although pressure is mostly subject to the master cylinder bore/travel than it is the booster/assist

As for op's question. I have the jb3 brakes on my 86 and love them. The jb3 booster and master cylinder feel perfect to me and react quick. Whereas the 70s trucks can standard with pretty much 3/4 ton brakes. I will have to look up bore size differences of the master cylinder through the years. But to me for some reason the lighter duty brakes seem to work better than heavy duty in at least the area of feel and reaction
A good upgrade is running 1.25 thick rotors on the front to help prolong the onset of brake fade. The next great upgrade you can do is get hawk hps brake pads. They bite a little more but don't needs I much heat like track pads would.

In a nutshell our truck brakes are pretty sufficient for most driving and can be upgraded pretty cheap with thicker rotors and nice pads. Unless you autocross which then maybe not so.

[Keith Seymore]

Originally Posted by INSIDIOUS '86

As for op's question. I have the jb3 brakes on my 86 and love them. The jb3 booster and master cylinder feel perfect to me and react quick.

JB5 system is perfect.

Feel, travel, effort are all right where I expect them to be - even after 27 years and 200,000 miles.

As a former brake development engineer for these trucks I can tell you it is the standard by which all other systems are judged.

K

Link to brake system release chart for 1987:

http://67-72chevytrucks.com/vboard/s...d.php?t=510519

[Tdubbyount]

Originally Posted by Desert1957

"Hydro-Boost" system has no effect on brake "Clamping Force" it takes the place of a Vacuum booster for reduced pedal effort.

Its is uses on Diesels and HD one ton's.

Master Cylinder applies ALL brake pressure.

Desert

Sorry, I'll put it this way. If you don't want to use both feet and stand on it, a hydroboost unit will help you get more clamping force out of your brakes. From my experience, my hydroboost setup totally blows my brand new vacuum setup out of the water. And it's stopping a 3/4 ton on 35" tires rather than a 1/2 ton on 31s.

[KQQL IT]

My brothers 78 has a hydro boost in a 1/2 ton.
Doesn't stop any different than my
'73 in fact has a worse/funky pedal than a vacuum brake booster.

[aotte1]

My head is stuffy tonight, what is JB5, the option code for GM brake package?
Thanks,
Les

[INSIDIOUS '86]

Originally Posted by Keith Seymore

JB5 system is perfect.

Feel, travel, effort are all right where I expect them to be - even after 27 years and 200,000 miles.

As a former brake development engineer for these trucks I can tell you it is the standard by which all other systems are judged.

K

Link to brake system release chart for 1987:

http://67-72chevytrucks.com/vboard/s...d.php?t=510519

The jb3 systems had 1" rotors and the jb5s had 1.25 rotors only yes? As well as the thicker boosters which are dual diaphragm?
This is on my 86
And this should be jb5 on my 78

[79 silverado]

Thanks for all the great responses and discussion, including (and especially) Keith for posting the brake sheets...

Is there an advantage to switching over to the system from say a 1987 that makes it worth while doing?

I have to assume that the factory stopped using the cast iron master cylinder for a reason, but not really sure what it was... cost/appearances or performance/durability?

I would be replacing everything top to bottom except the brake pedal, and I suppose could do that as well if required to get the best of performance/durability.

The only reason I would not consider a hydroboost arrangement is future motor swap potential... I'm not sure how well a possible lsx swap could be adapted to use the power steering pump for the brakes...

[Keith Seymore]

Originally Posted by 79 silverado

I have to assume that the factory stopped using the cast iron master cylinder for a reason, but not really sure what it was... cost/appearances or performance/durability?

Mass reduction was the primary motivation. Naturally, you get some corrosion improvement and appearance enhancement, too.

K

[LEEVON]

I loved the JB5's on my '87, well balanced, strong, predictable, service-able. All around great brakes.

[Desert1957]

Originally Posted by Tdubbyount

Sorry, I'll put it this way. If you don't want to use both feet and stand on it, a hydroboost unit will help you get more clamping force out of your brakes. From my experience, my hydroboost setup totally blows my brand new vacuum setup out of the water. And it's stopping a 3/4 ton on 35" tires rather than a 1/2 ton on 31s.

If you need both feet to stop your truck , Fix it before you kill someone....

Desert

[Desert1957]

Originally Posted by KQQL IT

My brothers 78 has a hydro boost in a 1/2 ton.
Doesn't stop any different than my
'73 in fact has a worse/funky pedal than a vacuum brake booster.

Exactly....

[Alex V.]

My '85 single-wheel, 454/auto C3500 has hydro-boost brakes. The pedal doesn't travel nearly as far as vacuum-boost setups I've driven before you get a good application, but aside from getting used to the shorter pedal travel I've never had a problem with them - in many conditions, the wheels (especially the rears) will lock up before you run out of boost. I think a properly functioning vacuum-boosted system is more than adequate for most trucks (save for something extremely heavy or towing something heavy) but from my experience the hydro-boost is at least as good a system.

And, as with my '67 Suburban that has a dual-diaphragm booster on 4-wheel drum brakes... just don't expect it to stop like a new Corvette. Being another car's length closer to the guy in front of you won't get you to your destination 10 seconds faster.