The Stovebolt Site Forums The Shop Area Driveline Question about brakes

Hello everyone. I haven't been on here in a while. My '49 3100 has been running pretty good until recently. Battery went bad back in late November, so with winter coming on, I thought I would wait until warmer weather to invest in a new battery. Bought a new battery Monday and got her fired up. Was going to run a short errand and when I started out of the shop and hit the brakes, the pedal went to the floor. I replaced the master cylinder with a new one about 18 months ago, bled and adjusted the brakes and had a good full pedal when the truck was parked back in November. I checked the master cylinder, and sure enough, bone dry empty. I checked around all the wheels, but I couldn't see any signs of wheel cylinder leakage. I did see what looked to be a little brake fluid on the left front tire on the inside. I'm thinking the wheel cylinder is probably bad on at least that wheel.

I've never changed a wheel cylinder before on one of these old trucks, but I guess it's time to learn how. Can anyone direct me to a resource that will walk me through the process? Also, should I go ahead and bite the bullet and replace all four wheel cylinders while I'm at it? Where's the best place to buy new wheel cylinders?

Thanks in advance,
Darrell

If you don't have a manual, that's a good place to start. The '48 - '51 manual is available online here at the Old Car Manual Project.

Take pictures before you disassemble. John Milliman posted a reminder sheet for brake adjustments a few weeks back (can't find it right now - apologies).

You suggest that one of the fronts is leaking, it would be wise to pull the drums off all four wheels and make certain that the one you suspect is leaking before you replace it, and that no others are leaking.

Others will chime in and offer more advice.

Have fun.

Bill

I would suggest doing all the wheel cylinders and the three rubber lines. I would also look at the hard lines very carefully. You will need a tool for installing the brake springs. Also it would be a good idea to leave one side together until the other side is done. That way you can compare the two.

Here's the Huck brake adjustment guide that Bill referenced.

BTW, you just received some excellent advice from Bill and truckernix.

Thanks guys. I appreciate the help. I'm going to attempt to tackle the project this weekend, or at least get started on it. I may have more questions as I get into it.

Darrell

I dove into the project last night. Got the two front hubs off. Figured I would do them first. As I suspected, the driver's side front had a problem. When I got the hub off, the brake shoes fell outward. The brake return spring was broken. There was brake fluid all over the brake shoes. Looks like the wheel cylinder is bad. I plan on replacing all four wheel cylinders and brake return springs, brake shoes and the two front brake hoses.

I'm not exactly sure what extra things I need to purchase to complete the job correctly. Can anyone help me out here?

Darrell,

I think truckernix nailed it. A complete inspection of your brake system is in order. If you replaced the master cylinder a while back it should be fine. The rubber hoses fail from the inside to the outside and they're inexpensive. I'd replace all three of them. If the hard lines are in rough shape, replace them too. You might be able to find some at your FLAPS or you could purchase a pre-made brake line kit from one of our vendors. Another approach is to buy the hard line and fittings from your FLAPS to make your own brake lines. You will need a flaring tool and and a quality one in order to produce brake fittings that don't leak. Since the LF shoes are soaked with brake fluid, you might as well get all new brake shoes while your at it. Examine the locks on the pins. If they've been used several times they may be thin or break when removed. Review the manual: brake spring tool, brake fluid, a length of 1/4" tubing, a container for holding the brake fluid that you bled out of the system, etc.

Remember, your life is riding on the brake system and that's the last place you want to take the cheap way out.

Thanks Andy. You're exactly right about not going cheap. I've done minor brake work on newer autos, but never done extensive brake work on an old truck like this. I almost wish I had someone to walk me through it the first time.

The truck had a pretty nice restoration on it some time ago. I bought the truck from a place out in Kansas and brought it back to Tennessee. Somewhere between me and the restoration, someone didn't take very good care of it, so it's really in need of another restoration. I bought it mainly to be an occasional driver and not a hanger queen, so it doesn't have to be perfect cosmetically. I would like it to be as good as can be mechanically, though.

You bet! PM sent.

Darrel, I live about 50 miles from Estill Springs, just off US Hwy. 64 between Pulaski and Fayetteville. Drop me a PM and let's get together. I spent 30+ years teaching auto mechanics before I retired in 2011.
Jerry

I ran into a snag this afternoon. I took the rear wheels and drums off and realized the back was not like the front. The rearend has been changed and I have no idea what it is out of. There are no tags or markings to identify it. I'll post some photos here and hope someone can help me. I don't know what brake parts to buy without knowing what rearend this is out of.

10 bolt GM, so there are lots of them over the years.



Ed

This is the driver's front wheel. I was able to disassemble everything. One thing I'm not sure about is how to get those brake pin locks off (photo with red arrows) and more importantly, back on. I got them off, but I had to bend them and I don't think they're reusable.

Thanks Ed. Is there any way to know what brake parts to buy for this rearend? I need to buy brake shoes and wheel cylinders.

Darrell

Unless those oddball locks break, they can be reused. If you want new ones most of the resto-ripoff places have them- - - -and they only want a couple of pints of blood for them. A 6-lug modern axle is probably out of some flavor of 4WD S-10, don't remember which years.
Jerry

I personally, am not particularly fond of those stamped sheet metal locks.

Right after I purchased my truck, the first this I did was go through the brake system. When I pulled off the rear drums, I found that one of those clips had fallen off.

Fortunately, there was so much rust and goop on the brakes and brake HW, that the pivot pin did not slide out, and the clip was stuck to the top of the brake shoe on the metal reinforcement, just ahead of the lining, so it did not tear anything up.

I reluctantly tried to get replacements, but did not have much success (there are multiple sizes, no one had the size I needed).

I wound up using stainless steel e-clips, which I ordered from McMaster Carr. The retention on these is much more positive than the original clips, and being made from stainless, they are never going to corrode.

One other recommendation I would make would be to lightly coat the outer circumference of the brake wheel cylinder, (under the cap edge in the area that the cap rubs against the wheel cylinder) with a high temp silicone based brake grease. Use one that is compatible with rubber brake components. DO NOT use a petroleum based lubricant, as it will attack the rubber cups in the wheel cylinders if it migrates into them. Since the Huck design does not utilize rubber dust boots on the wheel cylinder, this helps keep moisture and contaminants out of that interface.

Attached is a pic of brakes showing the e-clip.

Best Regards....

(Edit. Added a pic of the wheel cylinder. Silicone brake grease goes under the caps at the points shown)

Thanks for the tips Crowbar Bob.

Only thing I can add at this point is that I, too, used e-clips to replace the bendy retainer clips (I apologize if I am using overly technical terms here ...). Just be sure you size them correctly so they don't pop back off on their own (if too small), or slip off (if too big). If sized correctly, they should require a slight tap with a punch/chisel or something* to go on and give a nice little "pop" when they do. And remember that all the actuator arms (*the pieces that sandwich the actual shoe ends and allow the shoes to move) are sided. You have to put them back on exactly as they came off or you won't get the shoes to align coprrectly and your drum won't go back on. The process of figuring *that* one out made me pretty good at Huck Brakes ... I think I had them on and off and disassembled/reassembled enough times that I can now do it blindfolded ...

Oh, and now I get to do it yet one more time, thanks to Crowbar Bob ... (I didn't know about the silicon grease under the cap .... ) Thanks a LOT, Crowbar Bob ... I think I will accidentally delete your account now ...

*I won't tell you that I used a flat screw driver and a hammer because if I did, I would get the "right tool for the job" lecture from Jerry (It's No. 352 in his catalog, but it's included in his "Greatest Hits" anthology. If you would like to order the catalog and get any of his lectures from his "Slap up side o yore head" series, just send $9.99 to me here )

Another option if you're not building a numbers-correct concours restoration would be to use Tru-Arc snap rings- - - -the round ones with a couple of holes in the end for a snap ring plier to engage. Those things will stay put three days past forever if you select the right size, and they're easy to remove when it's needed.

John, I've found that those E-clips are a lot more controllable if you use a pair of Channel-locks to squeeze them into position. Those clips have a few nicknames that aren't suitable for use on a website with a few snowflakes with sensitive feelings!
Jerry

I think Jerry grew up with "Primitive Pete", or maybe he even developed those filmstrips.
I still remember them from shop class back in the dark ages.

Those names for e-clips came from " [expletive deleted], where did that dang thing go" when they flew across the shop.

I tore into the rear brakes today. I took the wheel cylinder off and it has the number Bi-TVS 3623 on it. I tried to cross reference that number to possibly track back to the make and year of the rear end. No luck. The brake shoes had Bendix 31474 stamped on them, but again, I was not able to get any information from that number. The hub doesn't have a number on it. I think I may need new hubs. They've got ridges in them. I could have them turned, but I just as soon get new ones. However, I don't know what part to look for at the parts store to make sure I get the right ones.

Darrell,
A couple things have not been mentioned yet;
1) I would have the drums turned and the shoes arced. If there is too little material left in the drums to be safe, the shop should tell you. Those drums can be hard to find in unused condition. Arcing the shoes means they are ground to match the radius of the corresponding drum. Once done, don't mix the shoes up with the other drums. This results in excellent stopping right away, instead of having to put a couple hundred miles of stop and go driving before they settle in, assuming you survive that long.

2) Consider re lining the cylinders with brass or stainless steel. This costs 3-4 times what a new Chinese cylinder costs but are better because they won't corrode or pit in the future.

Jerry (Hot Rod Lincoln) probably can tell you where to get both procedures done in your area, possibly the same shop.

Despite what people say about Huck brakes, I kinda like them, at least for my recreational use and occasional hauling. They require adjustment every 1000 miles or so but I can do all 4 wheels in about 15 minutes. My 3 Chevys older than 1951 have them and I can lock the brakes, as long as I don't have a heavy load. I cannot say that my Bendix brakes on my 51 are better. As long as you are not going too fast or using the truck as a daily driver, I would stick with them.

Kent

Arc-grinding brake linings is a pretty much obsolete practice, since virtually all the shoe grinders were scrapped years ago when the asbestos scare got into overdrive. There's a quick way to match brakes to individual drums, however- - - - -glue a piece of coarse sandpaper into the drum, and scuff the shoes inside the drum until the shoe and the drum match. If you use water-soluble glue on the sandpaper, a quick splash of boiling water removes it easily. Relining a wheel cylinder is only needed if the cylinder is pitted too badly to hone it smooth where the rubber cups ride. Even if you choose to replace Huck brake cylinders, don't discard the old ones. They're scarce enough that someone will probably want them even if they need to be relined.
Jerry

White Post restorations in VA or somewhere close back east relines cylinders, not cheap, the setup is all labor.

Ed

If you take a wire brush to the the outside of one of the rear wheel cylinders, you might find a casting number. The rearend should have some kind of identifying marks on it.
I was able to get reproduction clips ( pinlocks) for my 38 Master, which uses the same shoes and drums as the 1/2 Ton.

The rear end you have is a 10 Bolt Dana 44, most likely from a 1/2 ton GM 4X4. Attached is a guide that should help with further identification (year, model, gear ratio etc...) . Hope this helps. https://m.roadkillcustoms.com/differential-identification-chart/

Hi TUTS 59,

I agree that this rear axle looks like a Dana 44, but I am having difficulty placing it in a GM truck. I worked on a lot of GM light trucks in the 70s and 80s, and the ones I remember all had the GM (corporation) axles. I do seem to remember the 44 used on the front of some early Blazers, just not in the rear. (Of course, since I can't even remember what I had for breakfast this AM, you can take the above for what its worth... )

Were they used in GM trucks maybe before or after that time period ? If so, do you know any specific years that Darrell could use to help narrow down his search ?


Hi Darrel Day,

So it looks like we are still in ID mode here. A couple of suggestions:

1. Some axles are identified by a stamped number/letter combination. You may find it stamped horizontally on the centerline of one of the axle tubes, probably on the rear of the right tube for a Dana, although it could be anywhere. You axle looks in pretty good condition without a lot of rust, so you may uncover it after using a rag, some mineral spirits, and some elbow grease. This may yield a clue about its origins.

2. I remember seeing a lot of 44s in Jeeps. Maybe that's where your axle came from? I believe they used the same bolt pattern as the GM full size trucks? What is the bolt pattern on your truck? Are the rears the same as the front? I'm guessing the front hubs are probably original since the front still has the Huck brakes?

3. The shoe configuration appears to be the standard Bendix design. If you measure the inner diameter of the wheel cylinder, you may be able to match it up with one that has the same mounting configuration. If you can find a good parts store with an experienced (and patient) counter person you may get lucky. Likewise for the brake shoes and drums. I have also had some luck using online sources such as Rock Auto. If you find a matching part, you can often work backwards to determine the application. You just have to be careful that the picture they show is representative of the actual part, and not just a generic image.


Sleeving and rebuilding your existing cylinders is an option. As mentioned, stainless steel will give you added durability and resistance to corrosion. If your master cylinder is unsealed (i.e. no accordion type gasket on the cover) it is something to consider. I had my wheel and master cylinder done by these guys. They did a beautiful job that I was very pleased with. They even have a video of the process.

Wheel Cylinder Sleeving

However, since these are not original (the rears, that is) and are probably not rare, you may not feel its worth the cost if quality replacements are readily available. It just depends on your preference and budget.

One final suggestion. After looking again at your pics, it would be a good idea to relocate / replace, and anchor the brake line on the rear axle using clips that are held in place by the cover bolts. The way it is currently mounted makes it very susceptible to damage.

Best Regards...

p.s. John Milliman. If I lend you some of my silicone brake grease, will you promise not to delete my account ?

The Dana 44 could be from a Jeep Wagoneer or Gladiator, they are about the right width and were also 6 lug.. Just a thought.

Crowbar Bob (love the name, BTW that, and the big hammer, are my two favorite tools ...) ... Sure, send me the grease! I'll even give it back when I'm done with it.

Kent .... Can we talk about the whole "get the drums turned" thing? I can see addressing the drums if they are out of round or something bad like that, but if they aren't, and only just scored .... Sure, remove the outer ridge, but I agree with those who say if the drum is scored but still round ... why remove good metal and shorten the life of a hard-to-find part unnecessarily just to put $$ in the pocket of the guy who owns the drum lathe? Brake shoes are easier to replace than drums... Do scored, but still round, drums work just as good as smooth ones? Sure, there's a point where the scoring is excessive, but I think that is pretty intuitive to determine.

Discussion on this? Old Guys??? Am I smoking bad crack (again ) ??


John

If you think about it, the scored drums after the new shoes wear in have more braking surface. Back in another life when I had access to a brake lathe, and a lot of other cool tools, I turned the ridge off many a drum just to make it easier to get off next time. The company I worked for insisted that they be turned completely smooth so that’s what we did to customers drums.🛠

John,
I need to explain my situation regarding my thoughts on brakes. Both of my total restorations ('50 COE, '37 1/2 ton) involved trucks at the end of their useful lives, sort of like basket cases, but not quite. Shoes were rusted to the drums sort of thing. I am not an expert in automotive engineering and don't have a lifetime of experience with these issues. Forging ahead with advice from knowledgeable friends and a local shop, Phoenix Brake and Clutch, I had drums turned and the shoes ground to match the radius. The last time I did this was about 3 years ago and I don't know if they still do it and was disappointed by Jerry's comment that it is hard to find a place to perform this job. I do like his suggestion, however, of how to do it yourself. My first old vehicle was my '42 and I had the shoes replaced. without arcing, but the first time I tried to stop going down Elk's hill on Gurley street in Prescott, AZ I ended up going through a red light, despite cramming the brake pedal as hard as I could. With proper preparation on my total restorations, the Huck brakes can lock up the wheels and are much safer.

Thus, I cannot contribute more than just my anecdotes to this discussion. I was just trying to bring up a couple thoughts that were not addressed previously in this thread.

Kent

With regards to scored drums, I guess I really never thought of it too much as we were always schooled to ensure that the drum surface should be smooth and uniform. And of course, in any of the shops I worked in, that blue Ammco brake lathe was a standard fixture.

I guess you can make the argument about scoring providing an increase in surface area - although this seems marginal. The question remains if this would be offset by reduced contact in areas where the scoring might not be consistent. Certainly a rough surface is going to accelerate lining wear. Depending on the severity of the scoring, it may also produce a brake pull on the fronts if the surfaces are inconsistent between the drums. So, to do the job right, the drums should be resurfaced if they are beat up. I too, like HRL's suggestion about using sand paper to re-arc the shoes. Very clever...

That said, when I was just a wee lad, I remember watching my Dad, a consummate do-it-your-selfer, perform brake jobs on the family vehicles in our driveway. ("Always replace those shoes before you get down the rivets!" I can still hear him say.) Since having drums turned cost $$, I don't think he ever turned a brake drum in his life, and somehow our vehicles always stopped and we all survived. Although, I also think the asbestos linings of that era were a lot easier on drums than the friction materials of today. He must have also gotten lucky with the shoes he picked matching the drum diameter, because I know re-arcing, like drum turning, was never a part of his standard service procedure. I am in no way promoting this - but when you had a limited budget, and kids to feed, you do what you have to.

John,

There actually is a story behind my moniker. I worked for an OEM, and the building we were in had fairly strict union work rules. When we received instrumentation or equipment in wooden crates, we could only open them only if they were nailed shut. If the lids were attached with screws, requiring the use of a screwdriver, we had to get a union carpenter to open the crate for us. (Sounds insane, I know, but those were the rules).

Since we were often impatient, and a carpenter was not always around when you needed one, I brought in one of my Dad's old crowbars - one of the classic ones with the rounded end. (You know - the kind that Moe always hits Curly or Larry over the head with.) Screws or nails, it did not care, those crate lids came off with a degree of plausible deniability in case we got caught. ("I could have sworn those were nails.... You mean that little cross on the head means its a screw? … I didn't need to use a screw driver!....")

I kept it in my desk, where it just barely fit diagonally in the bottom drawer.

One day some millwrights were placing a piece of equipment and were having some trouble getting it located properly. They were lamenting that one of them would have to go back to their work area to get pry bar, when I opened up my desk drawer and offered up the use of my trusty crowbar. They were greatly amused that I even had such a tool, let alone how fit it into my desk. Since my name is Bob, they started calling me Crowbar Bob, and the name just kinda stuck. Years later, I would pass one of those guys in a hall, or even in another building and they would yell out: "Hey! Its Crowbar Bob!". Which was fine with me.

I have been called much worse..

Best Regards...

Kent -- Sorry if it seemed like I was calling you out. That was not my intent. When I was first learning how to do all of this (not from my dad -- he was challenged just by putting gas in the car), I got slapped in the head by a mentor who told me not to spend money I didn't have to, and then proceeded to pretty much say what Martin said above (and that the shoes would wear to fit the grooves in the drum ... which I never saw, come to think of it). Times, methods and materials change, so I thought it was yet another opportunity to explore tribal knowledge "hand me downs" to see it is still valid. In my own case, it's pretty hard to find useable replacement drums for the 1-tons.

Bob -- Great story! I'm sure once that got around, the union reps were pretty respectful when they came to your office ...

John,
No offense taken. I just had to make it clear I was at the end of my knowledge base. I would agree that unneeded turning of drums would shorten the life of valuable parts.

I did forget to mention that I had the shoes relined (bonded and not riveted) with the softest lining material they had. While not lasting as long, the softer material should provide more friction than the harder longer lasting material. I did not inquire at the time as to what type or the specs of what they actually used.

Kent

Bob, I'll try to answer your questions in order. I'm still in the middle of fixing the brakes. I'm still collecting parts.

The front brakes are original huck brakes and hubs. I have the hubs off, but still need to remove the wheel bearings from the hubs and clean them and repack them. The wheel cylinders on the front will be replaced with reproduction ones from ClassicParts.com. I've also ordered the brake shoe return springs, but they haven't arrived yet. I have new shoes waiting to go on.

I have a pretty good crew at my local Oreilly's parts store. It seems that the brake parts in the rear are compatible with a 1964 Chevrolet truck. I bought wheel cylinders and brake shoes for a 1964 Chevy and they seem to be identical with what came out. I also ordered all new hardware (springs, etc.) for the rear drums. I hope to start putting it all back together tomorrow. I'll have to wait until I get the brake shoe return springs for the front before I can finish it up.

I've also got new brake hoses and hardware to replace the old ones. I appreciate everyone's input and help. I may have more questions when I get to putting it all back together.

I am concerned that this excellent discussion has not included the issue of huck brakes on the front and bendix on the rear .

I had this (briefly) on my truck . Until I had to stop quickly one day , trailer was loaded . It took some quick thinking and clever steering action to prevent a nasty jack knife and subsequent impact with the car that had turned in front of me .

Yes , the bendix twin leading shoe does "self energize" , yes the huck brakes will stop you , but the energy required at each end of the vehicle is different and subject to change with load and road surface variables .

What am I trying to say here .........

Best to keep the brake types matched , as GM designed them .

In my case I changed the front hubs to take the bendix so they matched the rears.

Rock auto have a lot of parts at good prices .

I am getting slower in my uptake on details.

What make, year, size truck is being referred to regarding a mix of Huck and Bendix brakes?

In at least one year (1951?) larger GM/Chevrolet-trucks did have mix of Huck and Twinplex brakes. As I dimly recall, in that year the Hucks were on the front and the other style brakes (Twinplex - a self-centering/self-actuating/self-energizing style of brakes) were on the rear?

Good morning all. I am trying to locate the junction block that is connected to my master cylinder on my 54 gmc100. I have not been able to locate any similar part and my is leaking. I think I damaged my washers when I removed the junction block.
Thanks

If all else fails, try chevsofthe40s.com for the junction block. For 1/2 ton, about $18.00
Stewart

The OP has a '49 3100 with a later diff in it .