The Stovebolt Site Forums The Shop Area Driveline Brakes for 49 3100

Working my way through the 3100 getting it back on the road again.
Pulled all the drums last night and was surprised to see all but the right rear trailling shoe were all still very serviceable. The trailing shoe on the right rear is the only one that is worn down more than the others but still has alittle life left. Atleast enough to get it roadable.

The front bearings are different from any I've seen before. The ball bearings are big!
They too look very serviceable and I'm just going to clean and repack them.
The truck has been parked in the dry since 69 so overall brake component condition is unknown other than they no-workie.
There is no pedal at all.

I am pondering 2 points of attack and am looking for opinions.

1) fill the MS w/new fluid and pump away to see what happens.

2) disconnect all lines at MS and WS's then blow them out 1st then reconnect and try to pump them up.

what say yee?

I think you'll be better off to go ahead and rebuild the master and all wheel cylinders now as well as blowing the lines before trying it.

If this is a yard truck then maybe that approach might work. If it is for the road I would suggest replacing all the lines and rebuilding all the cylinders.

Peel some boots back and see what the fluid areas look like. That will give you a quick idea.

At least, a rebuilding of all cylinders and replacing rubber lines is a must if you want to drive at all. All the rubber will be toast.

As for the lines, inspect closely, any rust pull them.

You will be time ahead to just replace the steel and rubber lines now. Any junk in the lines will just cause you hassle later. Brake fluid absorbs moisture. So it is safe to say all your WC and MC will need to you rebuilt. Do you really want to gamble with this? Start with new lines and at least rebuild the MC and WC.

By the way I don't think there are boots on the wheel cylinders of that truck.

How quickly we forget. Brian has a good point. I forgot that I replaced all the rubber lines from the start as well. Since they are fairly common between the years for all these trucks they are available and fairly inexpensive from most auto parts stores.

Keep in mind that these trucks don't stop well at all when you slam on the brakes even with everything new and properly adjusted. Yes, the tires make a loud squealing noise, but not much stoppage. Kind of like trying to stop on ice, you have to pump the brakes to stop. ( I had to do that on a "pink" light" right next to a cop today. He just smiled and gave me the thumbs up. I must have left 50 feet of rubber on the black top.) Bottom line, whatever you do, make sure you do it right!

Because the rear cylinders don't have rubber boots the pistons are exposed to the air and tend to corrode to the cylinder walls. The fact one shoe was worn more than the other could indicate at least 1 is stuck. Maybe all by now.
The good news is that the corrosion is usually near the ends of the cylinder and not in the area that the rubber pistons will ever travel. They can be rebuilt nicely. The rubber cups are easy to find.

I just did a set. PM and I can give you some info on saving them.

Great info.
Well the juries in, I pulled the MS and all 4 WC's and it's not pretty. On the MS the cap disentigrated when I was trying to get it off. The resevoir had what could best be described as hardened jell in it. I tried to loosen the large nut that gives access to the piston assembly and couldn't budge it. It's soaking in PB Blaster to see if I can break it loose in a day or two. Off hand I'd probably be better of just replaceing it.
The WC's aren't much better. The cups are frozen and even high pressure air couldn't pop them out. They too are soaking to see if I can free them up.
With all cylinders removed I cannot blow high pressure air through the brake lines so theres no doubt that the "jell" is probably clogging them up or the lines have disentigrated internally and clogging them up.
Looks like the entire brake system is going to have to be rebuilt.
I notice some on-line classic parts houses carry full kits and I could probably find many parts locally at Napa and other Flaps.
Probably should research what it would take to put disk's on the front but $$$ is an object
Any and all tricks, tried and trues welcomed
Dave

After soaking the WS's a couple days in brake cleaner I was able to tear them down. All of them cleaned up good enough to rebuild and besides, w/the cast in "Made in USA" on them I definitely want to keep them. They definitely don'tmake them like that anymore. All parts are serviceable with the exception of the cups which I am going to try to source as oppsed to going w/a full rebuild kit. The pistons cleaned up nice and smooth and the springs have a uniform size and feel. In my haste to clean everything up and mixed all the parts together and soon discovered that there is a difference in size between the front & rear WS's. Thankfully the cups sizes were clearly marked once I cleaned them up and I'm guessing the bigger 1 1/4" WS goes on the front and the smaller 1 3/16" goes in the rear. I'll mic the pistons to make sure the larger (if there is a diff) go to the larger bore WS.
The springs are of 2 different sizes. Anyone know if the longer springs go in the front or rear WS's?

I found the clip on the brake rod end of the MS and was able to get some of the innards out but the piston is locked up tight all the way down in the bore so I'm going to try to soak it alittle longer to see if it frees up.
I'm also soaking the bleeder screws in hopes the holes can be cleaner out.
So I need to fiind a source for 2ea 1 1/4" WS's cups, 2ea 1 3/16" cups and 4 new bleeder screws, 2 of which are shorter than the other 2.
At this point I'm still going to stay w/drum brakes in the front ($$$'s) but I can see disc's in the front once some other more pressing issues are addressed. Has anyone adapted a new double resevoir MS to the stock drum brake setup?
Dave

Wheel Cylinder Specs -http://chevy.oldcarmanualproject.com/chevyresto/4885.htm

NAPA had all the parts to rebuild the wheel cylinders on my 3800. I can not see it being any different for a 3100.

I would consider Copper-Nickel brake lines if you are going to replace them. A lot easier to bend and flare, and does not rust like steel. I wish I did it when I worked on my brakes. As typical, it is a more expensive and a little harder to find.

http://www.copperinfo.co.uk/alloys/copper-nickel/downloads/is49-cu-ni-brake-tubing.pdf

Just taking a guess, you will also need new rubber hoses.

You should check the manual for the wheel cylinder sizes.

There is a product called Evapo-Rust. If you soak the master in it, it will remove rust and not affect the other alloys.

Napa

UP 3 - master rebuild kit

UP 8 - front cylinder kit (2 needed)

UP 9 - rear cylinder kit (2 needed)

Thanks for the links & info.
The progress thus far:
1) front cylinders were repairable. Cylinders,springs & end caps cleaned up nicely, the pistons were within spec and I found replacement 1-1/4" cups at O'reillys for a buck apiece. Rebuilt and installed.
2) rear cylinders had gouges too deep to work out. Got 2 new cylinders @ a good price from one of the boards sponsors. Pricing varied by as much as $30 ea. One installed, the other is awaiting time.
3) master cylinder was pitted and rusted beyond servicability, atleast for me. After soaking for 3 days I still couldn't get the piston out. Ordered a new replacement from another well known internet supplier. Those that were priced good were hard to find, same for the reurbs. Pricing varied by as much as $100!
3) Couldn't blow compressed air thru the hard lines. They are heavily rusted on the outside, must also be on the inside. Ordered and recieved a full 7 piece replacement set. Am going to try to reuse the 3-ways and rear offsets. Awaiting completion of the brake shoes.
4) replacing the 3 softlines. 2 in front, 1 in rear. They all are the same part. Best price was a local FLAPS (OReillys) for $10 ea.
6) the drums were in surprising good shape. Hand sanded them to a nice shiney finish and cleaned up.
7) wheel bearings were also in great shape. Cleaned and repacked. reused seals.

In over 4 decades of wrenching this is my 1st Huck brake rebuild and I spent so much time figureing the front out I only got a rear done before I ran out of time. Once I got the 1st front one done the 2nd was a breeze. Then I attacked the rear and they presented a double degree of difficulty over the fronts. I only got one rear done before I ran out of time but the last one should go better as my trick to hold the cylinder together AND the shoes up & ready for the spring install (ty-wraps).
I end up w/nearly as much wrench time rebuilding the brakes as I did getting the engine going.
Once the brakes are done I'll then have to shift to tires. Bset I can tell 215-75R-16's and 215-85R-16's are a close match to the original 600-16 but I haven't delved too deep yet.

Anyways shes getting closer to a road test
Dave

Spent this fine rainy Saturday removing the old steel lines and installing the new. I bought the kit from one of the forums sponsors and I gotta give kudo's as every individual piece fit perfectly, just like OEM. And no leak at the flares either. Since the body & bed is still mounted on the frame it took me a good solid 7 hrs to do the job. Man am I glad that part is done
One thing I found strange was having to go back and readjust the front shoes twice while I was using my vaccum bleeder. I don't think they were loosening up, I think it was more a case of everything getting settled. But I'll keep an eye on them.
These Huck brakes are definitely a different breed from what I'm used to.
I'm about as far as I can go with 1 man. I can pump up alittle pedal but nowhere near where it should be so I'm going to have to enlist a pumper I've never been able to completely bleed a system w/just the Mighty Vac vaccum bleeder. It does help tho.
The Mrs says I'm obsessed.
Getting closer.
Dave

I've got brakes!
Per the manual I should have around 3 1/2' of clearance between the pedal & toeboard witht he brakes applied and thats about what I have.

Is it me or is there alot of free travel in the brake pedal in Huck brakes?

In any case, it's a good solid pedal, the shoes are adjusted up alittle on the tight side and theres no leaks so I'm about ready to move on to the next phase, tires

.....after you drive it for a while you'll probably need to readjust the brake shoes....which has always been my experience as they "settle in".

....seems there was always plenty of free travel. As a kid I can still hear the clutch "bang" back as my grandpa would take his foot off the brake pedal. "Wham"!!

I would not drive it with the shoes dragging.

Update: I finally got to road test it and after the euphoria died down I got down to checking out all the systems. Static tests can only tell so much, road testing will reveal all the warts
Before the road test I had approx 5 1/2" clearance between the depressed brake pedal and the toe board, since the manual calls for 3 1/2" minimum I was very happy with that. After a mile or so and several applications of the brakes, the clearance shrank to a hair over 3", which put it below the minimum. I read somewhere that these Huck brakes will need readjusting after the break-in road test and sure enough, mine did.
I drive another classic car for fun that is much lighter than the 3100 and doesn't have power brakes either but it does have disc's in the front and the Bendix style in the back. I can see modifying these Hucks on down the road.
That said, they did stop the truck fairly well and if one of my used "may-pops" hadn't thrown most of the recap off, I'd probably be still driving it
Definitely need to stop farting around w/these wind-broke tires that came w/it and get the new skins
Dave

Glad to hear you had a successful shake down trip. Good luck moving forward. Remind your wife that Intense Focus is often confused for Obsession.

As you discovered, the brakes on these old trucks work very well when they are in top condition.

Brian, thats what try to tell her

truckernix, yes, they do work great when adjusted properly

Update:
readjusted all 4 brakes per the manual, tightend both shoes until the wheel drags then back off 4 clicks. At 4 clicks theres just barely alittle contact left as I can still hear it but otherwise the wheels turn easily.
I put the dust covers on and took a long hard shakedown cruise, back roads and stop & go traffic and I really worked those brakes. They held up very well and I didn't have any problems stopping, not even when a clown decided at the last minute to take a left hand turn in front of me...
Only issue is they squeal.
All 4 as best as I can tell.
I got the shoes at Autozone and I figure that has something to do with it. The shoes at the popular on-line classic parts houses cost twice as much as these did and this could be a case of me getting what i paid for. We'll see if they quiet down but it could be cheap shoes will squeal.
It could be a blessing in diguise as people can hear me brakeing and that may be better than that little brake light
Dave

They should quiet down after awhile. The newly turned drums need to be seated with the shoes. Shouldn't take long. Longer if you didn't turn the drums.