I saw something interesting on HighpowerTV Trucks. They were switching out the rearend on a dodge truck. The were using the wheel cylinders from a 2 ton chevy truck and said it would make the rear drums brake like disc brakes for cheaper cost. Has anyone come across something like this for our trucks? I am the process of going throught the 9inch I just bought and will be replacing the wheel cylinders. Is there something like this that could be used on the front to frey the cost of disc brake conversions?

 

i used a little larger bore 1ton m/c from a 55 on the 53 but i have no idea of the wheel cylinders . i'd almost imagine a little digging in an npd , or d.carpenter catalog would yield something . hades i'd be interested in it for 8.8 diffs now that i'm gonna use one in the 53 . i'd be willing to bet the trucks have larger wheel cylinders than the vic that donated it .... more food for thought as if my brain isn't going ten different directions all the time , and not much progress on it .......... as far as a disc conversion , in my case i bought then sold a " bubble " pi vic of 00 vintage thatd had the discs without thinking .................. go figure !!!!!!

 

Moving to the top one time to see if anyone else has anything to add

 

No and I really don't think you would want to. What they are talking about is a simple adjustment in the hydraulic advantage of th elarder wheel cylinder.

Brakes are really nothing to fool with. If you want something to act like a disc brake, then put discs on it - shortcut someplace else.

I'm gonna get reamed for saying this but it's a fact that I have experienced.

I have stock brakes on my 51 (or more correct, I have stock front drums and the stock rear drums that were installed on my 9 3/8 rear). And they are completely sufficient to stop that truck when I need it to. The only problem I have with stopping is having enough weight to keep the wheels from locking and skidding on the road - even with a load or towing , more than enough.

 

if a "bigger " mechanical advantage is what it's all about { duh kevin ! } i'd think you'd be acle to do something simialar by meesing with the pedal by moving it closer { extending it } for a greater mech advantage . i'll agree to a point with ya julie on the oe brakes . we seem to have quite a few idiots , as we all do , but it seems to me they like to find me and my ol' girl more oft than not . after a couple of hard stops the drums are pretty much saying nope i'm not doin' it again ! i don't drive it hard or fast , as it's no hot rod , and when it has been loaded down or yanking something around i take my sweet ol' time . i can't recall pappy but i wanna say my f350 had a much larger bore wheel cylinder on it and overall from what i can remember i believe it might fit the 1/2 ton drums . them and the larger bore master cylinder might do the trick . i'm doing the discs the hard way , making it fit myself , but with the proliferation of kits out there , and speedway has one in various bolt patterns for right at 300 complete , i'd rather go with them than mess 'round any further . oh and the guy's 'n' gals here showed me the light , get all the self adjusting stuff off a 68 -72 ford 1/2 ton and make sure the e brake is hooked up and functioning , and it fits your drums and walla your trips under to do adjustments are cut in half .

 

Kevins right but let me expand on my answer a bit.

First, Disc brakes were originally designed for aircraft. The reason the reason the design was adopted was two fold - first, they were much easier to maintain; and second with heavier aircraft and longer braking distances, they needed a system where the same braking coefficients could be accomplished with significantly less of the brakig surfaces in contact with one another at any given time - to allow for GREATER HEAT DISSAPATION. The design was adopted by auto manufacturers because they system was less expensive to produce and significantly simpler to maintain - not because it provided vastly superior braking performance or safety. That is simply an "old wives tale" that has been passed down from the days when disc brakes got adapted to race cars - again higher speeds - more heat - lighter-easier to maintain- .

Now one note I will admit to is that FORD had (has) a NOTORIOUS reputation for marginal brake systems. The early 70s vintage Ford cars in particular. But remember something: these systems are designed and built to carry not only the weight of the truck, but it rated GROSS weight, and stop effectively. Good point is they usually didn't go over 50 MPH - but 15 MPH isn't going to make that much difference. If you want to drive 80 or 90 and short stop then you better come up with something else.

These wheel and brake systems are designed and built to certain thicknesses, diameters, etc. etc. to interact with each other and do the job. When you start taking a stock system and strengthening something - like pushing the bake shoes up against the drum harder, lots of things are going to happen - yes you will brake faster. But you will also be subjecting the drum and the shoes to more heat in less time - coupled with more pressure on both. That may or may not put those two components outside the safety curve after a few brakes.

Here's another key point about 60 year old stock brake systems. I would venture to say that other than those of you who have recently rebuilt all you brakes, and have INSTALLED NEW DRUMS all the way around, 90% of you are driving on drums that are out of tollerance.

The spec on the F1 drums is 11.000 to 11.060. That's 6-100ths of an inch - in diameter or 3-100ths of an inch to the surface. Now I don't know if any of you have noticed, but these drums are pretty "soft" and with "hard" shoes installed (you can install shoes made of harder or softer material) you will probably only be able to trun the drums once - maybe twice, in it's life to stay in tolerance.

My point is if you are driving on drums that are enlarged, the braking efficiency is greatly reduced. You are also taking a chance because if they wear to a certain point, the drums get thin and will actually start to develop "tempered" or burned spots (those pretty blue spots) AND THEY WARP from heat.

And this doesn't include consideration for the condition of the 60 year old wheel cylinders and master cylinder.

I completely rebuilt my brakes and installed new drums all the way around. I adjusted the brakes to their proper positions. My truck is a 51 F1 with an FE 390 (with aluminum intake so it weighs within a few pounds of a 239) and a C6 (so the entire power train is about 150 pounds over stock weight). I took the truck to various speeds in 10 mph increments up to 100 mph - then stomped on the brake pedal.

There was no mushiness, there was no lagging, the truck stopped in the calculated distance for weight and speed (based on California Highway Patrol Breaking Distance Tables) EVERY TIME. The only problem I had was that above 60 MPH, the wheels would lock and skid on the tires. I put 1000 pounds of concrete in sacks in the back and repeated the test (up to 50 mph - stock steering still need king pins - you get it) - again no problems stopping.

Moral of the story is: if you use your truck as a daily driver, and drive it reasonably, the stock braking system will suffice and be safe. If you want to carry large loads or tow, then you would be better off installing an improved braking system - with greater capacity not simply a different design , and if you want to drive your truck like the villiage idiot, then please put better brakes on it so you don't kill someone else.

Modifying brake systems by substituting portions of them that cause other parts to work harder is EXTREMELY DANGEREOUS. Change out the entire system (like Kevin did) if you feel it's necessary.

 

Thanks for the comments. I saw what they did on HorsepowerTV to the dodge and had to ask about it for our old fords. I plan on putting disc brakes on some time in the future but thought if there was something cheaper for now to get a little better baking I would do it now. I am going through the 72 1/2t 9 inch rear end I just bought and putting all new brake pars on it.