The Stovebolt Site Forums The Shop Area General Truck Talk manual or power brakes?

I added to a previous post and was told i may be better off starting a new thread. I have a 39 1/2ton that i am looking to upgrade the brakes. Disc in front drum in rear. I want retain the stock pedals and add a dual master cylinder. I was told by another bolter that i would have to make a bracket to do so. which is fine but do i need power brakes. if so anyone who has done this on their truck maybe can give me a few pointers

thanks

What engine, and or how fast will you drive?

I chose to go with manual disc/drum brakes on my 54 Chevy truck for several reasons. The first and most important is, that lacking an ABS system, the manual brakes are just as efficient and I feel I have better control, especially in crisis situations.

Having installed power discs in my hot rod truck, I found that sitting in a straight up position, even with belts tight, and a cab mounted adjustable proportioning valve, I had a tendency to overbrake. With the weight distribution what it is in a pickup, I went with manual disc/drums in my Chevy truck and am totally satisfied with the brake performance. Granted, there is potential for more pedal pressure and travel, but I haven't had any situations where I felt I needed an assist.

I fabricated a simple "L" shaped bracket and mounted a manual Corvette disc/drum master with 2 and 10 pound residuals and an adjustable proportioning valve. Simplicity was a keynote, plenty of room for install and excellent performance. It may not be the only option, but I should at least be considered. I have pictures of the install in my "Shoebox" album. Hope this helps you with your decision.

Dave

Grigg..

Im putting a stroked 261 in it. I dont plan on driving too fast. say cruising 70 on the highway...


Dave

thanks for the input i will check out your pictures

Im not saying you'll have same experience as I did on my '50 3600 but,

Here is several options. Scroll down see if one fits your need or go to their other pages for more options. Their print catalog even has more various items.
http://www.piratejack.net/power_brake_unit.html


I was told by the company it wouldn't fit my truck.
I was told by others it would require modification.

Already expecting some custom work I went ahead and bought it.

The Booster/dual cylinder fit like a charm! Just bolted right up. Didn't have any problems attaching it to the original location and brake pedal assembly.

"Hope for the best and plan for the worst"

Im still using the single master and all drums on my 53 and she stops perfect. I see no reason to upgrade. A power booster isnt going to make you stop better, just with less effort on your feet. The key is to have all your brakes adjusted properly. From my experience even with crappy brakes, tires make all the difference in stopping power as your relying on the friction between the tires and the road to ultimately stop you.

Jeff

I have 2 trucks,a 1955 with discs up front and drums on the rear.It has the dual power brake master cylinder. My 1965 has the same disc drum setup with just the manual dual master cyl.Both are V/8 powered the 55 with a 350 cu.in Chevy,and the 65 with a 500cu.in.Cadillac engine. Both trucks have great stopping power.I agree it is just the pressure applied to the brake pedal,that makes any difference.Most of the vendors have a dual power brake master cyl.that mounts in the same position as the original.A very easy swap.

I agree 100%.
Got drum brakes and single master cylinder on my daily 1/2tonner for 12 years now and never felt the need for easier breaking.
I was surprised sometimes when I had to slam the brakes that you can even lock all the wheels at higher speeds.

When I replaced the original master cylinder many years ago, I ended up with one from a 1-1/2 ton truck.
Fits on the same mount, but uses a larger diameter reservoir and piston and has a bit more pressure than the stock 1/2 ton.

I just swapped to a dual reservoir/power unit in my daily driver '62 Suburban. I drove well over 20,000 miles with the manual brakes (4wheel drum).
I HIGHLY recommend the power booster.
You DO stop quicker. The brakes come in with less effort/pedal travel. (Most power conversions require you to drill a new hole in the brake pedal arm for the rod, apprx. 3/4- to 1-inch lower than the original hole...that changes your pedal ratio. Faster ratio for the same amount of leg travel).
It takes less effort to push in the brakes. That's very nice when you're rolling up on a the freeway off ramp, coming to a stop light, etc.
And where it really shines is when you're sitting in traffic. I'd bet money I'm not the only person who ever wedged their leg on the bottom of the steering wheel to keep the brakes tight after getting tired in stop/go traffic.

There's a tremendous amount of charm in driving a vintage truck...part of that comes from the Spartan interior, manual windows, that hollow sound the doors make when you shut them. Even manual steering isn't bad. But brakes shouldn't have "charm." They should work. And work darn well.
The next upgrade is self-adjusters in the drums. I figure one of the biggest things going against drum brakes was the manual adjust. I know if I adjusted mine when they need it, I'd be under there every month, easily. And who's doing that? I'm not. They won't be as good as discs, and if I start to tow the race car with the Suburban, I'll probably upgrade then, but for now, self adjust, dual-reservoir power drum brakes will be great.

And yes, I drive it like a modern vehicle; that means 80mph on the highway, 55-60 on the back country roads.

-Brad

I'm strongly considering front discs/upgraded drums for my truck. I don't mean to hijack this thread but it is such a related question. I'd like to know if it is possible just to add a hidden booster down next to my frame rail, working in conjunction with this stock dual MC that is on my firewall. http://rides.webshots.com/photo/2631539760071636143cKfnNW It is a dual because I have a hydraulic clutch.
I'm thinking that the clutch line can remain as is and a new custom line could feed a universal booster and proportioning valve that are hidden? I'd like to keep the engine compartment clean and "looking" stock. Does any one know if this is possible?
How about what parts are available and from who?

BTW, I was always led to believe that discs with a booster could drastically help decrease stopping distance with out locking them up. Please correct me if I'm wrong.

Fatboy0169; if you are intent on upgraded to front disc I would encourage the new dual system w/ booster. For alot of information just a couple pages back is this post I started which includes lots of information/tips on the overall system.
"Topic: new brakes want work, anyone please help"

Rustednuts and On the road again; My truck was my dads and dads dad before mine. Dad said "why the upgrade, truck always stopped for me." I told him it was because a new single mastercylinder was about 100$. A new dual cylinder w/ booster was only 200$. Plus, even though im keeping the current drum brakes today I plan on upgrading to disk someday since originals are non-self-adjusting Hucks, can't get new rear shoes, and all drums are turned as far as they can go and still needing. The new system is plumed so when Im ready all I will need to do is add disks, combination valve, and swap 10lb residuals for 2lb residual valves.

In my situation and unexperienced oppinion:
dual is better than single, safer
booster makes it easier
Needed all new lines anyway
Keeps doors open for future disk brakes
Brake parts for my 3/4 ton getting hard to find
Hard to find parts are more expensive
Truck's down to frame: now's the time if im gonna

The bang for my buck was the upgrade to avoid
"finacial short term gains resulting in longterm loss"

Grigg said something interesting about boosted brakes in another thread. It takes a certain amount of line pressure to lock up any individual brake. You may or may not be able to produce that amount of line pressure, even with a booster, if your brake hardware is worn or mis-matched.

Saying that " . . . when a brake is locked up the tire determines stopping distance . . ." is a little misleading. When the tire is locked up, even on dry pavement, it does not produce as much friction as it did just before locking up. On dry pavement, tiny particles of rubber are torn away from the tire surface and actually act as a low efficiency lubricant. I think that a lot of people have noticed that, without ABS, the place where your vehicle will stop after a skid is difficult to predict. That final resting place depends on a lot of factors, but, barring outside interference, (telephone pole, other vehicle, etc.) it will probably be noticeably farther down the road than is expected.

Dual master cylinders are a big safety factor. If you have a single chamber master cylinder and pop a brake line anywhere, you are left with the emergency brake. With a dual master cylinder, no matter where the brake line fails, you will probably have a lower pedal, but functional brakes on at least two wheels. That's a big selling point for me, especially on an old vehicle. Don't get carried away though. A quadruple master cylinder is almost sure to make emergency stops very exciting.

I may be fooling myself, but I would prefer to stick with non-boosted brakes unless it is impossible for me to lock them up. I have to admit that I have a tendency to get on the brakes, hard, when things go wrong. That isn't always the best idea. A few weeks ago I had a trailer jump the ball. Locking up the brakes would probably have been a bad idea.

Finally, if you have a dual master cylinder setup, I would always recommend a proportioning valve. I just haven't seen many vehicles that have exactly the same brake setup front and back. Even if the vehicle has the exact same brakes front and back, they probably won't have the same braking effect because of weight transfer. Identical brakes front and back with a 60/40 weight distribution means that the rears will probably lock up first, if I remember my physics.

I've got no problem locking up my wheels with the stock, manual brakes. In fact, they might just lock up a little too easy if you have to push hard for a sudden stop. I'm curious about how a booster and discs (non ABS) can help reduce stopping distance with out locking them up. It seems that it would be easier to lock them up with them. Maybe it's all about the pedal "feel" and sensitivity. Still looking for an explanation for this from one of the resident experts. I'm also still looking for an answer to my previous question about a hidden remote booster/proportioning valve downline from the original Master Cylinder. Any help is greatly appreciated.

I agree with you, bigmacdaddy. The wheels lock up at the end of traction. An educated foot might be able to play around on the edges of lockup, but I doubt that the average driver can do that. It seems to me that line pressure is the big factor for lockup. Once again, you may not be able to get there even with boost, but you really don't want to be there anyway.

As to:
I have no idea, but I'll bet that there are several here that do.

Here is some info I got from Inliners.

http://www.mpbrakes.com/products/product-detail.cfm?product_id=221

http://www.parrautomotive.com/

http://www.chtopping.com/StreetRodder4/

Now I gotta figure out the best parts to buy tpo complete my brake project. Any suggestions?

About the hidden remote booster.
I made one, but I would not recommend it, here is why:
You now have two systems to fail, the one going to the booster, and the regular brake system after it.
The system before the booster is a single system, it fails everything fails.

In my case I had little to no room on the firewall for a master cylinder, and the original single circuit just barley fit as the valve cover had been dented for clearance. I had no room for a 90 degree bracket like from a "bread truck".
I did use the original master cylinder, then a clutch slave cylinder, with one line in between this was the first part of the system, and the weakest. The "clutch" slave worked the push rod on a hydrobooster attached to a dual circuit master cylinder, and the rest of the system is normal from there. This let me install the booster and real Master cylinder under the cab where the Hydrovac was originally. Pictures of this setup on my link below under ford with 6V53T Detroit.

I gained boosted brakes for the huge disc front and rear. Non power brakes was absolutely not an option, (10,000 lb empty at up to 85 mph). the down side is the added complication and single line system to fail.


For the truck actually in question in this thread, I asked what speed, you say 70 and think it's not too fast. I say 70 is really fast for a single circuit master cylinder, and a great candidate for boosted brakes.

Personally I have had great luck and stopping power with original manual brakes, but that's 55 mph tops.
I think that much more than that and a dual circuit is a great idea, even if it does not help any it does help the safety factor, and that's a huge improvement, both for your safety and those around you.

Boosted brakes are nice, and while not always necessary I think always appreciated.

Grigg

I disagree with this logic.
A 1.5 ton truck master cylinder is larger than a 1/2 ton. this is so the larger truck can move lots of fluid to the larger wheel cylinders.

All you gained was less pedal travel and less mechanical advantage for your 1/2 ton. You move more fluid with the same stroke, but have less line pressure for the same amount of foot effort.

To get more advantage you would use a smaller cylinder, say for the 1.5 ton truck you put the 1/2 ton master on, if you keep the brakes adjusted tight and the fluid in the reservoir you would get really strong brakes with a long pedal travel, and hopefully you will not run out of travel before they lock up. You move less fluid but with higher pressure.

What you did didn't hurt anything, just takes more pedal effort.
The other way around would be unsafe, as you may not be able to move enough fluid for the brakes to function fully, and if out of adjustment you have less room for error (lower factor of safety).

Grigg