Who has installed front discs with no power booster---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

 

My 33 Roadster has drum rear and disc front with corvette manual master cylinder. Pedle pressure is just a little hard but its the way I like it. Going to a smaller MC like 7/8 you will have a softer peddle and a little more pressure. I just did a 200 mile weekend trip and I drive it several times a week.

 

my car is a little different its a 61 falcon but does have manual disc/drum on it with a dual res. master cylinder for manual brake application and it stops just fine. way better than the 4 wheel drum set up it had when i got it

 

Put 'em on my 50 chevy PU, used the ubiquitous (word for the day) Corvette/Chevelle MC. Drove the black pig every day for two years. Stopped straight as a string, lots of stopping power. Got the same type set-up on a 57 Ranch Wagon, but don't drive it yet. A vehicle as small as yours doesn't need power brakes or the hassle of locating a booster and all that mess. You'll be better of with the un-assisted brakes, I think.

 

This is one of those weird situations where I should know the answer, but I don't. I have been happy with drums all the way around, but the 40 style brakes are such a pain in the ass to keep adjusted, and now I have a drum out of round. So---rather than try and repair 70 year old technology, its easier to replace the front drums with a disc setup. Why should I know the answer---because in 1996 I built a T roadster with drum rears and disc fronts, and a standard Corvette dual chamber master cylinder with no power booster. It worked great, but it had front discs right from the get-go. I have never changed out the brake system on a car that was driven with drums to one that gets driven with front discs to have a "feel" for the difference.

 

I have a '37 Chevy pickup with GM disks on the straight axle and a '79 Firebird rear axle with stock drum brakes. The master cylinder is from a Ford. The pedal assembly is from Pete & Jakes, universal through the floor original looking type. I can't find the pedal ratio right now, but it was somewhere between a power brake and a standard brake.

Mine stops OK, but take a pretty good amount of pressure at traffic lights. Sudden stops are OK since you are in a panic mode anyway when slamming them on. Those who have driven my truck didn't complain or remark, so it must not be to bad.

My 120 mph drag car had the same disk/drum setup using the stock pedal and a manual brake Corvette master cylinder. I had no problem stopping it, even on the short track shut down areas like (MoKan).

Joe

 

i have done and driven several cars with this setup. my cars were heavier than yours, and with that corvette master, i could not lock up the brakes. i went down to 7/8s master and better, but still not the best. i bought a standoff valve and installed it in the front brake sys. and got them pretty good. my 40 ford that i have recently done ,is set up this way. call ralph at eci brakes , tell him your setup, and he will set you up. sharp guy on brake system. im doing a rpu at the moment, with 4 wheel disc.

 

I also have disc /drum non boosted on a single resovior in a falcon it stops great, just got a disc/drum non boosted dual resivior M/C I am about to rebuild to fit soon just for more peace of mind.

 

I've got a Corvette disc/disc master on my '57 Buick with Jaguar 4 wheel discs. I like the feel, the more pressure you put on the master the more brakes you have. You can definitely feel what is going on. I like manual brakes. I'm very happy with it and would do it again.

 

Mr A,
I went w/a chevy chevelle '68 or so master w/their discs on the first rod, used the proportioning valve that came w/it, and never had a problem. Used a '63-63 Vette rear w/drums.
Pedal response was ideal, so the linkage/lever arm issues worked out OK.
It's here where your best estimates might be of value. I didn't do anything out of the ordinary in terms of lever arm lengths. (you gain a bit of leverage as the distance to the fulcrum shortens, and I favored that side of the placement by 1/8th" or so)
Am doing the same approach on the new car, so we-shall-see!

 

I have them on my 32 pu, They work great the master cylinder is a 7/8" and is a duel type. The pedal is a little hard but not bad, this is the second set I've had on the truck lotsa miles works good.--TV

 

I have 4 wheel manual disks on my daily driver '65 Corvair. The biggest thing is balancing the master cylinder to the calipers. Mine uses '85 Camaro MC & front calipers all the way around. The brakes feel firm, with no undue extra force. Heck, I'm teaching my 14 year old daughter to drive in it, and she doesn't have a problem stoping it.
Eric

 

68-70 Mustang disc up front with 11" rotors.
11" x 2 1/4" 1968 Merc wagon drums in back.
7/8" Torino M/C - very much the same as the typical Mustang dual cylinder except the outlets face the frame with the M/C installed roadster style.


I also run silicon fluid.
No probs with any of it in 15 years and 49,000 miles.
Did replace the front pads a couple years back, but it wasn't really needed.
They would have went 50,000 - 60,000 miles.

The car has a proportioning valve, but in my opinion it's not needed and is in fact cranked nearly all the way off.
Engineer a space in for one, but try it without first.
I'm doing that with my 31 on 32 frame roadster.

I have residual valves on the front brakes, but not so sure they're needed there either.
I'm not going to have any on the 31 either, but I may have a hold-off valve that delays the front brakes coming in.
Maybe, the 32 doesn't have one of these and it stops quite well normally and in emergency conditions.

The brakes have a little softer feel with silicon fluid, but no big deal.

No booster and none required on these little cars.
When you consider that some factory cars have a brake pedal - with booster - that is so easy to push that having to hold your foot off the pedal in traffic is a major pain in the aft.
You do need a little pedal resistance to make life easy.

These pics show the Mustang M/C on my 31.




It's on a Deuce Factory bracket which has a bolt on side that's not shown in this pic.
The 32's Torino M/C has the outlet on the opposite side as noted.
Both M/Cs on the roadsters are 7/8"

The 31 has Camaro 10 1/2" rotors and 62 or so Ford F-150 1 3/4" rear drums.


I put a lot of thought into this setup and I think it will balance out quite well with the narrower rear brakes.

The slightly smaller front disc brake 10 1/2" rotor should work as well as the 32's Mustang 11" rotor since both setups came on cars that weigh about the same.

Don't know what prices are nowadays.
The Mustang disc setup - not counting adapter kit to the solid axle - cost $300. in 1985 at about a 25% discount.

The Camaro disc setup - again, not counting adapter kit - cost $200. in 2001 at about a 25% discount.

Good stuff from NAPA fwiw.

If you've ever driven a Pinto, pedal feel and effort is about the same as it is in my 32.

The 31 is still a project and hasn't been driven yet, but I expect it to be the same as the 32 brake and steering-wise.

The only disadvantage I have is the Chevy pass car bolt pattern up front and Ford pass car bolt pattern in the back.
Not a prob with my dual pattern steelies or slot mags that have uni-lugs.

I have a uni-lug slot mag wheel for the spare in the 31 as well.
There is room in it for a spare.

Trunks beat hell out of rumble seats in my opinion, but you're set up even better since you're driving a truck....

 

I have done this MANY times;
My 32 coupe - Willwood 4 piston front, 11" Ford drum rear - Non power Maverick disc/drum master
29 RPU - Chevy single piston fronts, 10" Ford Drum Rear - Non power 67 Mustang Disc/Drum master
63 Falcon - 4 piston Kelsey Hayes front, 10" Ford Drum rear - non power Maverick disc/drum master
62 Nova - 4 piston Willwood front, Chevy 10 bolt rear drums - non power aftermarket disc/drum master
62 Ranchero - 4 piston Willwood front, 8" Ford rear drum - non power Maverick disc/drum master
i could go on but i think you get the picture. All of these cars have very good braking power and good pedal feel. Pedal pressure is reasonable, my 5"4" 100lb. wife has no problem driving them.

 

On my truck I have 70's chevy truck calipers with 76 ford rotors up front and 1970 ford truck drums in the rear with a late 70's ford 3/4 ton truck non-power master cylinder.

The truck has a little firmer pedal than the stock setup but it brakes very nicely and doesn't require much pedal pressure.

 

I used to have a non-power disc setup on a Nova years ago. Worked fine; power assist is nice but I found I could push the pedal awfully hard if I got scared.....

 

I converted my '46 Ford over to disc front/drum rear with a dual chamber non-boosted master cylinder located under the floor. I also installed a proportioning valve in the line to the rear brakes. Stopping wise, the system works much better than the stock set-up. It takes a bit of "leg" since it isn't boosted but nothing like the original set-up.

 

Thank you all very much for your help and pictures.---Brian

 

I have a off topic car that i converted to four wheel disks and am using a manual 72' vette master. Stops good.

I also had a 57' Pontiac with a disk conversion on the front that was running a manual master, but from what I do not know.

 

I have discs front/drum rear on my 53 F100 and my 46 coupe. I find the setup works just fine for me. I have used a power booster on my 40 coupe but it is not yet driveable, so I can't make that comparison. Hope I don't hate the power set up. Joe

 

The circle track guys do this all the time, no power assist, just pay attention to your MC piston and caliper piston sizes and pedal pivots when you engineer the system.

K

 

I have disc on the front of my '55 Chevy and stock drums out back. I am not using a booster or a proportioning valve. And here is the kicker, I'm using the stock single master cylinder. Has been fine for years. Could use a little more pedal but stops fine. Drove it for years in LA traffic daily.

Bart

 

The entire brake system was transplanted from a 1971 Camaro with no real changes. Non power M/C under the floor, distribution block, front discs using the low buck kit and the complete rear. And no it did not have any aftermarket valves that are have become all the rage. I think the pedal was Pete and Jake or equivalent. The brake pedal and low buck kit were the only non Chevrolet parts.

I put many a mile on it and as far as I know it still is running the same system. I still see it around and it worked so well I can't imagine a need to change it.

One thing to keep in mind...this was almost 30 years ago before the "quick take up" brake systems became popular to increase gas mileage. All calipers are not made the same inside. All of my parts came from the same donor car except a new replacement Mcyl. I rebuilt the calipers and W/cyls myself so there were no mismatched parts.

 

I just changed out the front drum brakes on my 68 C-10 to a 73-up disc setup and without changing the MC to a disc version, I already can tell a good bit of difference. So much that I am debating going any farther. I have a power brake booster and MC from a 79 C-10 so I probably will change out eventually (I'll have to get a prop valve) but as of now, with the stock drum master cylinder, it gets the job done pretty well.

 

This was done on our 57 Chevy when we got it. Works great, stops on a dime, not much more pedal effort than non-power drums and lots more stopping power.

 

I have disc/drum on both my 47 ford and 55 chevy, with no booster, and it works just fine.

 

I had a 39 Ford convert with a posi nova rear axle and and used the nova disc on the front,,,used the original nova master cylinder with no problems. HRP

 

brian - I use this as a guide for all my braking questions. It shouldn't be a guess as to what master cylinder you use. Discs will work fine with manual master if you have the correct master cylinder. Mine are manual and they work great.

http://www.mpbrakes.com/technical-support/reference-master-cylinders.cfm


http://www.mpbrakes.com/technical-support/configurations.cfm

 

You put a Chevrolet master cylinder on your '57 Ford with no booster ?


CBB

 

I have a 1" bore corvette m/c behind the dash and 4 wheel metric GM discs on my track roadster, plumbed direct, no distribution block or other valving calipers are fed with braided hose. Works, great , moderate foot pressure, no hunts or dives. They work at altitudes from 22' to 14,000'.

Charlie