Who has replaced front drums with discs and no power brakes---and ran them??

I am getting ready to install disc brakes on the front of my RPU to replace the tired 40 Ford drum brakes. Rear brakes will still be stock S10 drums. I do not have power brakes, just a standard Corvette double chamber master cylinder under the floor. Who has done this, and what difference did you see in stopping ability and required pedal pressure? Please---no theoretical answers---I want to hear from people who have actually made this change and driven their car---with no power brake booster.---Brian

I converted from manual front drums in my Chevelle with a 454 (3800lbs)to manual front discs. Stopping ability was greatly improved, pedal pressure was about the same "lots of pedal pressure". So then I changed over to power. Changed the master cylinder to a power unit and booster. Stopping is the same but much, much less pedal pressure.

You probably won't have as much pedal presuure because your is considerably lighter. I have a 51 Ford Rat Rod with 11" Chevy discs in front and 10 bolt Chevy rear. I'm using the manual Corvette front disc master I took out of my Chevelle. It stops good and not too much pedal pressure because of the lighter weight.

Just remember that a liitle pedal ratio makes a BIG differance

Ive never converted from drum to disc, but i personaly like the feel i get with no power booster. I ran the merc with a camaro subframe with discs , but i left out the power brakes it stopped fine with little pressure.

Ran discs on many cars with no power booster, even on all four wheels... As Jerry mentioned, pedal ratio is important as is the size of the master cylinder. On a light car with disc front, drum rear, a 7/8" or 1" cylinder with the appropriate residual valves and probably an adjustable proportioning valve will work fine... I do, however, always check and set my brakes on a new build using brake pressure gauges to balance the fluid pressure at the wheels...

My 34 Plymouth has disc up front with no power boost. Takes a bit of pedal to haul it down from normal cruising speed but it does it and with no fade. Of course, it also helps that I have discs in the rear as well. I think you'll like the conversion if done right.

Dave is there a good book or place to read up on this.
This is also the first time I've built a brake system
from scratch, and I would very much like to get it right.
And need to learn about the right proportioning valves
and what to use to check the presure and how.
Thanks Kurt

We have 4 wheel disk on the Model A and no power. It stops fine, good pedal feel too.
Larry

i converted my chevelle no power brakes works good stoping at 130

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Originally Posted by vara4

Dave is there a good book or place to read up on this.
This is also the first time I've built a brake system
from scratch, and I would very much like to get it right.
And need to learn about the right proportioning valves
and what to use to check the presure and how.
Thanks Kurt

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Brake pressure gauges to check the pressure. Lots of the dirt track supply places sell them...Speedway has them for sure. Here's a site with some good brake and suspension information.....



http://www.hotrodders.com/kb/suspension-brakes-steering

Thanks Dave For the Info. Kurt

The 55 has disc/drum & no power. Stops fine. No choice w/ 4" of vacuum.:eek:

The 32 has disc/drums & a booster under the dash (Kugel 90 degree unit) & stops waaaay better.

I wouldn't worry about it.. 40 Ford brakes don't self energize so there is no mechanical advantage on them like there is on self energizing drums, and there is no mechanical advantage on a disc brake system.. so the braking effort will be the same, just you will stop faster due to the more efficent brakes

I have a 54 Ford that I converted to manual disc brakes in the front. At the same time I changed the rear brakes to a wider shoe/drum. This is a very heavy car, much more weight than yours. I used a non-power disc brake master cylinder (two bowl).

I am very happy with this setup. Yes, the pressure required is more than with a power brake setup, but less than the old drum brakes on all four wheels. I had a major emergency requiring to me slam on the brakes doing 65 mph on an interstate and the brakes came through with flying colors (it stopped the car quickly and without hitting anything.)

So---Today I ordered up a complete front disc brake set-up for the roadster pickup, from Hortons in Milton. Rotor & hub combination, calipers, pucks, brackets to mount calipers, bearings, spindle bearing adapters, and requisite nuts and bolts. This is to go on '40 Ford spindles which are currently running '40 drums and shoes. and the price for purchase, Goods and Service tax, sales tax, and shipping??--Step back---step way back----$874.00. Yeeouch!!! Damn that hurt...

Lot of money yes! But if you can stop quicker and shorter you can save that and more if you ever need to stop quickly in an emergency situation. It's money well spent where it counts.

I have non-boosted discs on my 33 coupe. It takes a fair amount of leg to stop the car. It does, however, stop real well. I think the biggest factor is that I am used to power brakes so manual brakes seem like a lot of effort.

I did a disc brake conversion on my 1930 Ford coupe with '40 Ford spindles. I have a dual master cylinder mounted under the floor. Under normal driving conditions I feel the need to pump the brakes. They do not feel right on the first application of the pedel. I have bled the brakes and installed the residual pressure valves front and rear and have an adjustable proportioning valve for the rear. I believe the problem lies in the fact that the master cylinder is below the calipers in front and can never be bled properly. If I pump the brakes just once, then it feels fine and stops really good.
With that being said, I had an emergency stop on the way to the NSRA nats at Richmond in 2006. A car turned in front of me at an intersection and I locked the brakes up in a panic stop without pumping them. They worked fine although my hotrod was severly damaged.
Bottom line is, I have the car back together now with no change in the brakes and I have to assume they are OK do the the fact that they stopped the car in an emergency as was expected.

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Originally Posted by dans30

I did a disc brake conversion on my 1930 Ford coupe with '40 Ford spindles. I have a dual master cylinder mounted under the floor. Under normal driving conditions I feel the need to pump the brakes. They do not feel right on the first application of the pedel. I have bled the brakes and installed the residual pressure valves front and rear and have an adjustable proportioning valve for the rear.

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What front calipers are you using?

Bob

I used a kit from ECI back in the early 90's with standard GM calipers on my 1930 Ford.

My 2c, our 55 has manual disc front/drum rear and stops fine at +100mph. As for pedal pressure, I don't notice any difference. But since I only run it at the track my heart rate is up a little! I also used the Corvette master. Yes, it does get pricey!!

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Originally Posted by dans30

I used a kit from ECI back in the early 90's with standard GM calipers on my 1930 Ford.

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Would that be the '78-'87 A / G body "metric" calipers or the earlier A body calipers? I've heard of problems with the "metric" calipers. Been told they are "low drag" to retract the pads more than the earlier type, and this can result in a low pedal when not used with a quick take up master cylinder. I've got them on my T roadster, and have the same phenomenon, but It could be just air in the system.

Bob

My T uses Wilwood, non power assisted disc brakes up front with a mustang master cylinder and a 8 inch rear end with drums. That set up hauls the t down with very little effort! I had 69 GTO disc brakes on the front before I switched over to the Wilwood set up and it was fine too (Just too heavy of a brake set up for the little t) Don Jr.

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Originally Posted by brianrupnow

So---Today I ordered up a complete front disc brake set-up for the roadster pickup, from Hortons in Milton. Rotor & hub combination, calipers, pucks, brackets to mount calipers, bearings, spindle bearing adapters, and requisite nuts and bolts. This is to go on '40 Ford spindles which are currently running '40 drums and shoes. and the price for purchase, Goods and Service tax, sales tax, and shipping??--Step back---step way back----$874.00. Yeeouch!!! Damn that hurt...

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Good grief - that's a lot of bucks, CDN or USD or any other currency you want to spend!!