im not sure what exactly you're building here... but if youd like you can have all the parts off my 41/46 chevy truck it too had manual brakes. send me a pm if you're interested
Zach, ...let me start out by saying that what you are asking is about as controvercial as politics or religion. And in most circumstances, the reason people get so defensive about those sort of topics is because they are not as knowledgable as they should be about the subject, --and what is being said is not believable to them. Therefore, take what I say about mechanical brakes with a grain of salt but do understand that we generate about $20K-$30K of annual income at my shop just specializing in mechanical brakes. My clients ship cars from all over the country for the sole purpose of us going through their brakes. I offer a guarantee that when we are done repairing their brakes, they will be able to go out on the 4-lane road and do ten (10!!) consecutive panic stops from 45 miles an hour, and they will have brakes that will slide the wheels and stop their car equal to what hydraulic Ford brakes will. Part of this guarantee includes that if they will not do this, I will refund all of their money and install a set of hydraulics for free. I just looked and in the 2006 fiscal year we rebuilt mechanical brakes on 19 (!!) vehicles. In all the years I have been in business, we have never had to go back on our guarantee. Now saying all of this, one needs to understand the theory behind mechanical brakes and why they were phased out of production. Contrary to what is said, it was not because they were inferior to hydraulics. They were very labor-intensive in their day (and today too) and so manufacturing costs along with labor costs caused their demise --but do understand that they have the capability to stop a vehicle equal to what a hydraulic equiped vehicle will do with the same size drums. PLUS, whatever the condition of the mechanical brakes were when you parked your car will be how they will be 6 months or a year from now. Hydraulics have a nasty habit of leaking when they are parked. Starting from the beginning, every part needed to totally rebuild a Model A or early V-8 mechanical braking system is available in a good quality part. Understand that there is also inferior parts being manufactured that are not up to the task over the long run. Know what you are buying/using! Also, a person needs to know how to correctly inspect, rebuild, and adjust a set of early Ford brakes. This means that there must be minimal-to-no 'play' in the linkages. Brake rods must be straight without bends or kinks. Brake drum surfaces must be within spec (not turned too thin) and brake shoes MUST be arc-ed to the drums to provide a minimum of 80% or better surface contact. This is imperitive! When someone tells me that they must adjust their brakes often, I immediately know the shoes are not properly contacting the brake drum surface. Also, the brake shoes MUST be centered in the drums under a load. Brake roller tracks must be flat with no worn areas. The reason this is imperitive is because loose wheel bearings or a worn race on the bottom of the axle housing will allow a hub (and drum) to ride higher. When the shoe is expanded out (as the brake pedal is applied) the arc of the shoe is not in the same arc as the drum so little surface contact is made. (Hydraulics can overcome this when the driver gives the brake pedal a second pump which forces the shoe to temporarily move the drum into alignment with the added line pressure.) Also, another problem many mechanics do is use an incorrect hardness of brake lining for the drum used. Most Model A's for example used a stamped steel drum. These drums require the use of a soft lining that must be stretched prior to riveting. Too hard of a lining, --or too loose fitting lining will cause chatter. The stamped steel drums cannot be machined because it causes them to be too thin. Ole 'Hank' addressed this in his Service Bulletins back in the day that worn drums must be replaced and not machined (turned). When the drums are too thin, it allows them to expand. I touched on bearings and races above, and will discuss spindle bolts (king pins) and radius rod ends. If the front end has the opportunity to rotate or move under braking, this allows inconsistant braking which can cause darting or pulling. I find that most people who complain about mechanical brakes that are pitiful also do not have a tight front end under their car. Therefore spindle bushings, wheel bearings, and the ball on the front radius rod ("wishbone") must be tight and within tollerances. I will close by mentioning that Flathead Ted's floaters concept has been around for years. I have been making another version of that for years out of the stock parts. Just like a quarterback does not make a football team, the same can be said for mechanical brakes. Have some good parts mixed in with the bad parts will allow you to have marginal-to-decent braking. Everything properly rebuilt to factory tollerances as they were designed and you will have brakes that will pin your nose to the windshield. This does not come easy, ...and it does come with a price. I hope this gives you an honest opinion towards mechanical brakes. Hydraulics will likely be cheaper, and hydraulics will definitely be easier but there is a huge amount of satisfaction garnered when you can prove the nay-sayers wrong and show them that mechanicals can do everything that hydraulics can do --except for leak!!
The Flathead Ted parts mentioned earlier are from New Zealand or Australia - can't remember which off the top of my head, but they are gaining many fans amongst the Model A fraternity. I have a set but haven't fitted them yet as I'm doing other stuff first but I'll let you all know when I do. Aside from that, I've run mechanicals for 3 or 4 years and as long as you know your cars capabilities and you keep on top of the adjustments, they'll be fine. I even tow a family sized trailer with my A with no braking problems, just as long as I'm sensible with it.
Look, you're a hotrodder., and hotrodders back in the day adapted various pieces from different cars, so why not find some hydraulic brakes from...say...a 1929-1936 mopar and use them? It would still be period perfect...
having never gone through the whole system, and wanting to upgrade my drums and all that, what do the experts reccomend as far as parts? Which are the best available, where do we get them etc.? I think it would be best in the name of safety to name names
I've got two model A's with mechanical brakes, and I can lock up the tires when I come to a stop. Freaks out old ladies. heh... My '37 Plymouth had juice brakes. If you lived in the late 30s and were a mechanical brake hater, you probably would have found a way to put juice brakes on the car. They did exist at that time. Perhaps you can modify Plymouth brakes to your ride. I'm a nostalgic ford lover, but there were people doing hop up projects using parts from other car manufacturers in that day. Fluid filled shocks were used from GM cars on Fords... I'm sure you could use hydraulic brakes with a little creativity. You can also get mechanicals to lock up the tires!
One could have been, but the other was definitely homebrew; you could see where the wheel cylinder retaining area of the Chevy backing plate had been brazed to the A backing plate. I've also seen ads in mid '40s Speed Age magazines for "universal" wheel cylinders to be used as an add-on to any mechanical brake car.
Keep it interesting....mechanical brakes....no seat belts...non safety glass in the windshield.....the doctor will be on the accident scene after he saddles up his horse.....Just like the old days!!!!
well , I almost had a failure on my first car, a 1930 model A. After a day of driving it everywhere around town, on the hiways, and in the boonies, Later I was checking my battery and happened to notice that the the cotter pin had worn out on the main brake clevis pin, and it 'was about to come off '. Another time I found out that Model A,s had a wonderful springy front bumper, as a little old lady panic stopped for a yellow light. It was a slo torture as i tromp'd on those mech. brakes and glided closer and closer and bounced off her rear bumper.
My opinion, anyone who goes out on today's roads with these women (and men) who have there cell phones permanently attached to their ear and tries to rely on mechanical brakes needs some serious sit down and think about it sessions. Period correct may be ok, but there is such a thing as going overboard. This is one of them. Remember, this is not the 30's - you got cars that go much faster and stop a lot quicker today, and drivers who couldn't care about you. There is a reason manufacturers went to hydraulics - SAFETY
I had a 38 Ford pickup with string brakes and they were fine, in fact, they performed better than my 38 Coupe with 39 hydraulics until I had a booster fitted. Get it HOT! Hit it HARD! for christs sake stop in time... thats the wife and the car.
I put 3K miles on my '38 last year with mechanical brakes. I don't have one complaint about it's stopping power. My longest trip was a 400 mile round trip to Nashville & back via I-40. I did really watch where I was on the road and who was around me. I always do my best to keep a decent "halo" around the car on the road. You can't control everything but if you're paying attention you can do a lot to reduce risk. JH
Mine need an adjustment. If that doesn't fix it according to the manual it's a time consuming job to do a first class inspection and repairs to keep a mech system in tip top shape. Damn the torpedoes I'm going hydraulic. I will focus on minimal debauchery of the original chassis though.
Building a car to "exacting" period details isn't really building a Hot Rod -it's really more of a Restorer's effort. Restoring a car while challenging is nothing like building a Hot Rod. The old Hot Rods were BUILT - improvements were made out of necessity, creativity, pride and accomplishment. Faster rides needed better brakes - Hot Rodders recognized and acted on that simple fact from the very beginning.
Drove a 37 slantback sedan in high school with mechanical brakes. Constant adjustment for best performance. Had it where it would lock up the wheels, but still required two feet and all the push I could muster to stop it when going fast or for a sudden stop. Many a scare, both feet on the brake, fast gear downs and heading for the bar ditch to avoid hits! Planned stops, as mentioned, not bad. Panic stops are just that! I can't remember now, but there was an add on that gave some more leverage that seemed to help some, but I was so glad when I got the 40 with juice brakes. With traffic today, I would not run mechanicals, my 2 cents worth.
HemiRambler, I don't think that's really fair. There's still a lot of innovation how the basic parts go together when building a period correct hot rod. The "restorer" HAMBster has simply challenged himself to do it without deviating from a parts pile available in a particular year. True restorers are already locked into one of a finite number of combinations that came from the factories. I think something like a real formulaic circa-1950 hot rod (black Deuce roadster with a Mor-Drop, '48 Merc flattie, '39 box, '40 juice brakes, etc.) is still a very exciting and fun project, out of the ordinary for most areas and most importantly to this discussion, definitely HAMB material. Maybe that's a form of restoration, but I still think it's worth discussing here. Despite my earlier comments (and I think lowering the suspension is still the most important argument for hydraulic brakes), I think a completely viable hot rod can be built with mechanical brakes if he wants to. I look forward to seeing what kind of innovations he makes with the mechanicals if he does. That's still hot rodding to me. -Dave
Early V8 Garage in Covina sells a kit that's all bolt-in, so you won't have to butcher your frame for most of the early cars. Or you can fab one up yourself - I did it on my '34 & it wasn't too hard. End result worked pretty well too (F100 up front, EF out back). http://www.jalopyjournal.com/forum/showthread.php?t=93219&highlight=tech+brakes
Bigcheese327, Yeah - I can see how one would think that -fair enough, my comment wasn't made to be popular. Don't get me wrong though - some of those cars are really cool - and I certainly recognize the skill it took to assemble them. My comments were directed at those who remind me of the restorers I've met. With the restorer crowd - all the thinking, origionality and individuality is removed from the equation - what we're left with is still reflective of the skill of the "builder", but not exactly what we'd tend to think a builder/hot rodder really is. Reminds me of my Uncle the painter - once I was looking over his lifetime collection of paintings when I noticed that one out of a zillion was not signed. I asked him why and he told me that nearly all his paintings were "his own" scenes from HIS mind - memories - and whatnot, but THAT one painting was a COPY of a picture he saw in a magazine - as such he felt he could not apply HIS NAME to another's work. His skill and talent was no less on this particular piece, but it made no matter - he would not claim it as "his work". In a way - this is how I see the guys who are so intent to copy an era that they do not allow themselves to "stray". Clearly better brakes were available in the 30's - so as far as I am concerned the "pile of parts" is there. Not wanting to use them - is (as far as I can see) the type of "restriction" that a restorer would place on himself. Keeping to an era is great - we all do it to an extent - it's when you let that thought squash common sense and creativity is when I think it takes away rather than adds to a car's build. Let's face it - as "builder's" of cars we have an obligation to the rest of road to make our cars safe. If we choose to ignore that responsibility - eventually the government will step in and force us to. The posters that state they have mechanical brakes and can lock them up and leave four black streaks does not mean for one second that they have brakes equal to hydraulic- sorry it just doesn't work that way. For instance, I have yet to see a mechanical brake that had a proportioning valve - then again at 30 mph you probably didn't need one either. Go to a drag strip and spin your tires at the starting line while the car in the next lane shows you his bumper. Traction is key to making you GO and STOP - not skidding. You generate HEAT to stop your car - maximum heat generation equals maximum braking. The start of any well thought out design is to consider the requirements - the conditions in which your design must function. Can someone go cross country with sub par brakes ?? Sure you can - a little luck, paying extra close attention - all factors to improve your odds. Then again go out and run someone's kid over and spend a lifetime regretting your decision to be a "purist". Hot Rodder always meant the opposite of Purist to me. This whole idea of blending the two leaves me baffled. The modern challenge for Hot Rodders is to build a "traditional Hot Rod" BETTER than they once did while still having the heart and soul of yesteryear. Then again I drive a Rambler so what the hell do I know.
has anyone done a calculation on the pressure exerted by the brake shoes on the brake drum in both hydraulic and mechanical systems?
Probably ...but what difference do you think it makes? I personally do not think it makes any difference.
my thoughts are that brake shoe pressure is stoping power, if we compare mechanical and hydraulic brake system with identical drums and shoe linings, which one creates the most brake shoe pressure?
Well said HemiRambler!!!! I've always felt that some guys take building a traditional hotrod a little overboard.......but they do produce some sensational cars and I like seeing 'em. I don't see it as restoring a car persay.......more trying to restore a MOMENT IN TIME....and to get the feeling of what the original hotrodders may have felt at that time. I think you can capture SOME of that feeling....but not all of it. That's how I view alot of trad cars, Timemachines....... Whatever you decide Zach, I have a feeling it'll be GREAT!
Well, I see where your thoughts are coming from but remember that there is a point where shoe pressure exerted against the drum causes enough friction to stop the rotation of the drum. All the pressure in the world won't help you after the drums have quit spinning. What most people do not realize is that a properly rebuilt set of mechanical brakes only require about 1/2 pedal travel to adequately stop a vehicle at speed, --and at 2/3rds pedal travel (1/3rd pedal travel still left from contacting the floor), the wheels are locked up. Therefore when the "experts" tell you that they had rebuilt brakes and they had to 'hope & pray' that they could stop, I know that they did not have "rebuilt brakes". Generally speaking, any reproduction part that Brattons sells is the best quality. Especially since he manufactures about 70% of his own brake parts. Don Snyder (Snyders Ant. Auto in New Springfield, Ohio) manufactures the balance of the good stuff needed however there are some items that Don stocks that Specialized (Mac's Wholesale) makes. Mac's is basically the 'Wal-Mart' of the Model A & T industry and they will manufacture an inferior piece to be able to sell it at a cheaper price. Many small dealers buy from them because their profit margin is greater. I try to steer people towards items that Bratton's carries because of the quality. If the item is not very good, Walt usually prints that in his catalog telling it is foreign made but the best available, --or foreign made but good quality.
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