Did they put power boosters on drum brakes?

[Zone47]

My 68 11" drum brakes are the worst thing ever. I just got done buying new shoes, wheel cylinders, turning the drums, installing new rubber lines and the truck still takes a ridiculous amount of effort to stop.

It's not like I race it or go fast, I just want a basic driver to go to a cruise in or the hardware store, but it won't stop very fast as is.

I don't have the bread to blow on a whole disc setup, that's why I rebuilt the standard drums. Would a booster help out at all?

[Kw69]

I did this change on my 69. I purchased a power booster from eBay and installed it. I like the way it stops quickly. I wish to have purchased a factory one because it would have sat on the wall instead of a few inches off. Regardless it works very well, and stops very quickly. I thought of going to a disc set up, but decided not to and keep it original as much as I can. Plus to add an aftermarket disc set up, it gets expensive. So to me it's worth the upgrade. That's my take, hope it helps.

[elorenzof]

We have a power booster in out 70cst. There is an option code on the glove box door for it.
I just replaced it a couple of weeks ago purchased from Napa for $98.00. Everyone else wanted $275 or more.for some reason I can't upload pics

[Steeveedee]

Originally Posted by Zone47

My 68 11" drum brakes are the worst thing ever. I just got done buying new shoes, wheel cylinders, turning the drums, installing new rubber lines and the truck still takes a ridiculous amount of effort to stop.

It's not like I race it or go fast, I just want a basic driver to go to a cruise in or the hardware store, but it won't stop very fast as is.

I don't have the bread to blow on a whole disc setup, that's why I rebuilt the standard drums. Would a booster help out at all?

Possibly, but standard manual brakes in good condition should safely and easily bring your truck to a stop, even when loaded to its capacity. A booster only makes for reduced pedal effort. Millions of them were made as manual drum brakes. What are you comparing your truck's stopping power to?

[jocko]

Yes, many pre-71 4-wheel drum trucks were ordered from the factory with boosters. Adding a booster will not change the stopping distance or increase braking performance at all. It does significantly reduce the pedal effort as Steeveedee mentioned. You mention it takes a lot of effort to stop (booster will definitely help you here), but you then said it won't stop very fast as is (booster will not help you here). Hope that helps. In these old trucks, especially the all drum trucks, when you're in traffic with all the new cars with 4 wheel disk and abs, ya kinda need to (at least) double the ol' 1-1000, 2-1000 rule of tailgating. These trucks' brake systems were very good for their day - and are still very good today when tuned and maintained (as you've done), but the stopping distance of newer cars is dramatically shorter than these old trucks, so a big part of the safety equation is the realization that, even new and tuned stock brakes on your old truck will not equal modern vehicle performance - and adding additional space between you and the guy in front of you.

[kwmech]

3/4 ton 1968 here with big block and power drums. Stops very well, even with a full load.

[toolboxchev]

Yep, all the above is true. I have a 70 C-20 with Drums all the way and boost, stock.

Doing the rears for the 3rd time in 12 years only due to crappy components and bad drums. Did not expect that one to last. First complete rebuild lasted 10 years.

They work, I can lock all 4, or just to the limit very easily on a well maintained system. It does come to a halt rather easily. Dimes so one may say.

[Zone47]

I should mention that my brakes are the 2" wide shoes.

I'm comparing them in the current condition to something that will actually skid the tires if hit hard (mine won't even do that). So since the fronts are rebuilt, I'm going to look at the master cylinder and then the rears. The pedal is still mushy even though I got all the bubbles out of the front and rear bleed. They are the most disappointing brakes I've even experienced. Thanks for all your replies, I'll figure it out.

Originally Posted by Kw69

I did this change on my 69. I purchased a power booster from eBay and installed it. I like the way it stops quickly. I wish to have purchased a factory one because it would have sat on the wall instead of a few inches off. Regardless it works very well, and stops very quickly. I thought of going to a disc set up, but decided not to and keep it original as much as I can. Plus to add an aftermarket disc set up, it gets expensive. So to me it's worth the upgrade. That's my take, hope it helps.

Thanks, I'll check that out!

Originally Posted by elorenzof

We have a power booster in out 70cst. There is an option code on the glove box door for it.
I just replaced it a couple of weeks ago purchased from Napa for $98.00. Everyone else wanted $275 or more.for some reason I can't upload pics

Cool, there is a Napa nearby. I'm thinking I'll need another master cylinder too. I might try Summit racing too, they are just down the road.

[rjs53]

My 69 came with power drum brakes. It didn't run well enough to know how well it stopped. Should be the same booster up to last 70's early 80's

[Mike C]

The drum booster is different from the disc booster. On my 70 C2500 I converted to disc but kept the drum booster. It doesn't have as much vacuum assist as the disc version but worked good for me.

Parts store boosters don't usually come with the brackets that locate the booster up and off the firewall. But that is how the 67-72 power brakes are mounted unlike the later trucks.

[davepl]

My Dad's 68 was manual brakes, and I had a '69 that was power brakes at the same time. They are definitely different, and if you're not used to the manual, they do kind of suck. But they will safely stop the vehicle, and so work.

So if they're not working, something's wrong. But if they suck and take a lot of effort, that's just "how they are" I'm afraid.

[BCOWANWHEELS]

manuel discs take a lot of pedel pressure also. I have both.

[68Gold/white]

3/4 ton drum brakes have much larger drums/shoes. I have never driven or experienced one,but am not surprised they do a much better job of stopping than a 1/2 ton with 11X2 shoes and drums

I sold auto parts from 1985 to 1998. When looking up front brakes for the 67-70 pickups there's a listing for a larger shoe. I NEVER had a customer with the optional shoes ...on a pickup. Then a friend comes in store, approximately 1998, at the end of my parts tore career (Thank You, Lord!!!) He had a 69 Suburban, It had the optional larger shoes. It really surprised me. I'm guessing that the larger 67-70 shoes option may have only been on suburbans, who knows.

I'm the Yahoo that had a customer with a 70 1/2 ton that had factory disc brakes (my catalogs listed disc as an option in 1970). We've discussed it here some time back, but it seems as it may be a very rare deal, or his pickup may have gotten converted to disc...enough off topic...

Zone, I'd get your rear brakes repaired properly, make sure master cyl is good, get brakes properly bled. Then see how you like it. As others have said, booster just reduces effort.

I have 67 nd 68 C-10 LWB's, both will have disc brakes when driven again, no way I'm doing the 4 wheel drum fiasco, ever! I am hoping to get my 67 going, here within a year, plan to try manual disc setup, see how that works...

Several companies make 6 lug disc brake conversion kits. You might consider saving up for one of these setup's. That setup would save you money by not having to convert the rear to 5 lug axles and drums. I plan to convert mine to 5 lug though....

[jjzepplin]

My 70 4x4 had power drum.

[weq92f]

Your drum brakes should stop your truck easily with effort on the pedal if they are operating properly.

It is possible your adjusting procedure is leaving the shoes adjusted too far away from the drums requiring too much shoe/pedal travel?

Try pumping the pedal to get a firmer feel and/or more braking power at the wheels ( this is a long-shot but if this works, your MC is bad ).

Hth,

-klb

[Dirt's72]

My 69 has power drum brakes and listed on the spid as well. The truck stops very well in comparison to my old 67 that had standard brakes.

[4carbcorvair]

My 68 K20 has power drum. So as others said, Yup!

[72LB]

My 69 is power drum.

[Zone47]

Originally Posted by weq92f

Your drum brakes should stop your truck easily with effort on the pedal if they are operating properly.

It is possible your adjusting procedure is leaving the shoes adjusted too far away from the drums requiring too much shoe/pedal travel?

Try pumping the pedal to get a firmer feel and/or more braking power at the wheels ( this is a long-shot but if this works, your MC is bad ).

Hth,

-klb

First of all, thanks so much for everyone who chimed in. So, this^ ended up being the problem. The shoes were not adjusted right.

First of all, I adjusted the new fronts and then drove the truck but should have re-adjusted them because they seemed to 'center' and needed tightened up again.

The big problem that I wasn't aware of is the rears were totally out of adjustment. In fact one of the rear's clicky thing to keep the shoes from backing off wasn't working. It free wheels either way. It's like all the teeth off the star thing is rounded off, so I need to replace that. Once I adjusted the rear and bled them, then I had a hard pedal and the brakes work 100% better ... or the best they can as designed. It is actually a good feel and fine for normal driving.

I'm not so keen on drum brakes but after this experience, I'm at least better educated about the whole deal and again I appreciate the help here!

[dave666693]

do you need a proportioning valve with power drum brakes?

[RodnRudy]

No, the stock distribution block is all you need

[Myoldtruck]

I have a 70 c/10 that I converted to power drum brakes. This is my every day driver, and I also tow a 23' airstream trailer in the summer.

Cleaning 40yrs of dirt and grime from all parts in the drum is key. greasing adjusters so they spin freely in your fingers. Putting anti seize on high spots of backing plate where shoes slide against. Making sure your drum access holes are drilled open to adjust your shoes once your all reassembled.

Buy the very best shoes available and put them in, in the correct direction. There is a smaller shoe and a larger one per wheel. Im using napa ultra gold shoes. There is also a company musclecarbrakes.com that makes a premium shoe, they dont fade as much if hit 2-3 times hard in a row.

I dont need a gorilla foot to stop now with the booster is in place. These are old trucks and should be driven with 100% input from the driver, unlike the autonomous cars of today that self correct from a lack of input.

[89AKurt]

My previous '69 half ton had a one ton booster, also had a brake job. It still stopped like a 50 year old truck. Current '68 has no booster, but it's also a manual, and I have no idea on condition of pads but it's doing ok.

I also live in a rural town, not a city. But if I leave space for stopping, two people will dive in without signaling, so it's still dicey.

[6T7 C10]

Yes a booster was an option and in some cars was standard with four wheel drums. On my 67 C10 I added an 11" booster and 15/16" master cylinder on stock rebuilt drum brakes. It will lock the tire up and locked up is locked up. Drums will stop just as well until they get heat soaked in repeated hard breaking then disks really shine.

[saxart]

Originally Posted by Myoldtruck

Cleaning 40yrs of dirt and grime from all parts in the drum is key. greasing adjusters so they spin freely in your fingers. Putting anti seize on high spots of backing plate where shoes slide against. Making sure your drum access holes are drilled open to adjust your shoes once you're all reassembled.

THIS!!!!



When I bought my '70 I drove it home with one wheel that had barely working brakes. (Didn't know it till I pulled everything apart) Luckily it was only a 2 mile trip! The rears were rebuilt, but the truck sat and the rear wheel cylinders were locked up from rust. One of the fronts had a completely collapsed rubber hose, and the other front hose looked like you could barely shove a spaghetti noodle through it once I cut the end off to check it. Anyway, after a complete 4 wheel brake rebuild, and the addition of a power booster, the brakes are fantastic. I know drum brakes don't work well in the rain or once heated up, but I think a lot of the bad rap that drum brakes get is due to poorly (or never!) maintained set ups.