Rear Brake Options 87

[305_Square_Body]

I have a 1987 R10 Silverado. Have been agonizing over my rear brake options.

Option 1: purist approach and install new drum brakes.

Option 2: disc brake conversion with the kit requiring axel removal.

Option 3: bolt on disc brake conversion that doesn’t require axel removal.

I will likely remove 305 and replace with 350 in the spring. Daily driver type stuff mostly.

Thoughts?

 

[Craig Nedrow]

What rear-end does the R10 have? 73 FF 14. I did drums, because I could get them local ie. fast so went that route. I like the simplicity and weight reduction of discs. HOWEVER, the FF 14 has three different (at least) factory braking setups. Mine is the smallest 11X2., or close. There is a 13 inch option, think 2.5 width. If you decide on drums, go big. Hydroboost is next on my list, with big drums, think it would be awesome. 2 cents

 

[Keith Seymore]

My vote is option one.

For daily driver use the factory configuration should be fine.

Mine was a daily for 30 years and 200,000 miles.

K

 

[fast 99]

No need to reinvent the wheel. Stock GM SB brakes are probably the best system out there.

 

[Bennyt]

Rebuild the drums. You won't find much if any improvement in performance with rear disc's unless you are looking at a big brake kit with 4-6 pistons. The rear brakes do 30-40% of the braking, less unloaded. Disc's might give you a 10% improvement over the drums. So 10% of 30-40% isn't much and you'll be fighting parking brake issues and more. I've yet to see a kit that bolts on and doesn't require significant investment in time and money to sort it out.

 

[GTX63]

I would only go with rear discs on a truck I was hauling or pulling heavy loads, and in a mountainous area. I'm in Tennessee and I still wouldn't do it.

 

[Keith Seymore]

Rebuild the drums. You won't find much if any improvement in performance with rear disc's unless you are looking at a big brake kit with 4-6 pistons. The rear brakes do 30-40% of the braking, less unloaded. Disc's might give you a 10% improvement over the drums. So 10% of 30-40% isn't much and you'll be fighting parking brake issues and more. I've yet to see a kit that bolts on and doesn't require significant investment in time and money to sort it out.

Plus - the rear system line pressure is regulated down via the proportioning valve.

If a person wanted more rear brake why wouldn't they just change the proportioning, open the pressure to the rears and let those puppies hunt?

Way easier than melting and re-pouring the whole rear brake system.

It's like driving around with a restrictor plate on the motor, and saying "whelp - I guess I have to build a new motor" instead of just removing the restrictor plate.



K

 

[Keith Seymore]

What rear-end does the R10 have? 2 cents

8.5" ring gear 10 bolt, btw.

K

 

[MikeB]

Even the 2"x11" brakes with finned drums work very well. An optional brake package (JB5?) would have used 2-3/4" wide shoes. Keith would know for sure.

Do use name brand shoes, and do not machine the drums. Problem with that is the shoe arc would be different than the drum arc, causing the ends of the shoes to not touch the drum surface. Unless, of course, if you can find a shop than can "arc in" the shoes.

As for aftermarket rear discs kits, you could probably write a book about all the problems folks have encountered with them.

 

[David King]

An old saying comes to mind, "If it ain't broke, don't fix it"

 

[Geoduck]

I agree, stay with stock drum brakes they are simple and reliable.
Mike B makes an important point...... Quality brake pads do make a difference. I'd be curious what pads folks suggest.
Also you may want to look at replacing those aging brake hoses.

 

[F-64]

I have an 87 R10 longbed.
I run a Willwood proportioning valve on the stock rear drum brakes. I had to remove the stock valve as I'm running a larger diameter tire on the rear compared to the front. I need to be able to adjust the balance.
I dialed down the rear brake pressure a lot. Unless you are carrying a load in the bed your rear brake pressure is very little.

The biggest change you can make to the R10 is improving front caliper brake pressure. I couldn't lock up the front brakes with the stock vacuum booster. I would roll through red lights with brake pedal buried.
I put a 3/4 ton hydroboost unit on my R10 and it has been perfect.

Another option is to use an OEM Hella vacuum pump to increase the pressure output of the booster( they have these pumps on Audi, Corvette, VW, Volvo, and many more).

Electric Vacuum Pumps | HELLA

www.hella.com

I used one of these on a Kia to increase brake pressure by supplementing engine vacuum. You'll need some check valves, electrical relay, and an adjustable pressure switch.
And if your engine dies, you could still have power brakes if the electric vacuum pump still has voltage.

Anyway, the stock drum brakes are more than adequate on an R10.