disk brakes not power?!?

[FrankHoy]

I got a suprise today, working on my 71. I noticed that it has disk brakes on the front but does not have a power booster. I had purchased the truck at night, so never looked very close at the brakes before. They have always worked but definitely NOT power. I had just assumed it was all drum due to not having a booster. I believed this to be an all original unmolested truck, excluding a different bad paint job. I have a couple questions, hopefully some of the brake experts can help with.

First off, is this common or did this even come from the factory like this? My option sheet on the glovebox doesn't mention anything on for brake option?

If this did come from the factory like this, can I just add a power booster? I do have a couple extra, complete with master cylinder. Would anything else need to be changed?

Any insight greatly appreciated!

[FRENCHBLUE72]

You can just put on a power booster but, make sure you have the booster brake rod and not the manual rod .... If I am wrong some one pleease correct me..

[Stocker]

Since discs require a higher line pressure than drums, there is normally a proportioning valve. Does your truck have one? If not, I would guess the discs were installed by a PO, and you may want to install one with the booster.

[Slammed67]

Unless it's really hard to stop the truck without a booster, I'd just leave it alone. I'm running a late model master cylinder with no booster and disc brakes up front and it stops just fine without excess pedal effort.

[dinnut]

all 71-72s had disc brakes. not all of them had power brakes though. my 72 doesnt have power brakes. to convert to power brakes you need the booster, the bracket, and the rod.

[FrankHoy]

My truck does have the proportioning valve. The brakes work and it does stop but with alot more foot pressure, compared to my 72 with power brakes.

I am using my 71 to teach my oldest son to drive right now and he has a little more trouble, than me, with the manual brakes, being he's fairly short and lightweight. I think I may end up letting him have it for his first vehicle. He really seems to like it and keeps hinting that he wants it. That's why I would like to add the power boost, if that is all it really needs.

Are the pedal arms different, as with some cars? I can't really tell comparing my 72 to the 71. It has a different rubber pad but I think that is just because it is a Cheyenne and the 71 is a Custom.

[71-longbed]

i have manual brake in my 71 ..... it took me a few weeks to get use to the added pressure i needed to apply .... if anything i think i would help your son learn how to leave plenty of room between cars when slowing to a stop ... thats never a bad thing to learn early on .... im told i tailgate ... and i dont even realize it... old habit i guess

good luck

[Sweet72]

I thought disc brakes were optional in 71 and standard in 72. My 72 GMC C1500 originally had manual disc brakes.
Can someone please set the record straight?

[acloco]

Yours should already have the proportioning valve for disc & drum. Just add booster.....and the correct length of rod for the pedal...some are the same...some are not....depends on the booster.

I have a 65 Chevelle SS with power drums...everything is new or rebuilt...still has the original shoes on it all the way around...and it stops on a dime.....if you have never driven a power drum...it is like driving a power disc brake car for the first time.

Go with the power disc brakes.....

[Baradium]

71 and 72 had standard disc brakes on the 2wds.

IIRC 4x4 axles still had drum fronts, at least in the heavier trucks. I seem to remember there were no provisions for a dana 44 disc braked front end until a few years later.

'70 and before there weren't any discs on the pickups.

Clear enough?

[lukecp]

One of my friends had a '76 C10 with manual disc brakes, and PS suprisingly.

I kinda like manual brakes. You have to push a little harder, but it is a bit more fun, lol.

'71 up 4x4's also had disc brakes up front

[krue]

The pedal arm should be the same whether you have power, manual disc or drums.

[Rod]

Power brakes became standard equipment on 3/4 and 1 tons in 71... but 1/2 tons it was still an option all years.

[jorgensensc]

My '72 cheyennesuper had manual disc brakes. I swapped those out for power as soon as possible.
Manual is o.k., until you really need to stop and can't lock up the brakes, even when standing on the brake pedal

[Longhorn Man]

Why would you want to lock up the brakes?
I prefer the non power myself, you get a better feel, you can run bigger cams, less things to brake, and no "OH SH*T" feelings when you lose vacume for one reason or another and have to hit the woah pedal.

[Sweet72]

[QUOTE]Originally posted by Longhorn Man

I prefer the non power myself, you can run bigger cams

I like your thinkin Longhorn Man!

[jorgensensc]

I only say lock up the brakes because when I'm in an emergency situation I like to lock the brakes then back off. Sounds crazy I know, but it lets me know I am applying the most pressure. When my brakes don't lock up, I spend precious seconds trying to figure out ifI'm going to stop, and if my brakes are working!
If that makes any sense. Maybe I'm strange.

[Perchjerker]

LMC truck mag states that all Chevy trucks went to front disk brakes in 1971. That means that no 1971 trucks were built with front drum brakes. My 1971 truck has disk brakes in front.

[FrankHoy]

Don't believe everything in the LMC catalogs. Although they are great for reference.

I know that there are 71 & up trucks with all drum brakes. It may have been a special order thing. There were and are still a lot of old schoool drivers that refuse to anything but drum brakes.