Disk brake conversion question

Undead_Edsel_59 · LONDON, ONT

Disk brake conversion question

Petebil · ONTARIO

As long as the bore of the AMC master is the same or close to the 79 T-Bird, it should work. Don't forget to check what pedal ratio you have.

fatchuk · ST MARYS, ONTARIO

For that heavy of a car, I would not even consider manual brakes. She would be a tiring day driving with no brakes..disc brakes will work much better with a booster ,,The set u have described is a cobblers brake and I doubt the proportioning valve would work as you would need to install pressure vales to inline to keep the rears from passing you .. also being a licensed wrench I would not likely safety that set up..With the disc set up from the 79 you should not have much trouble finding a master, booster, proportion valve set up in almost any wrecking yard or somebody on here most likely has a parts car ..I am pretty sure most of that stuff could easily be found I think most stuff from a crownVic, Marquis , or several other Fords up till the ninties would be a better way to go cheaper, easier to source new stuff .. In the interest of building a safe car why even mess with that old mixed crap..just seems to me safety should be that most important part of building a car would be safety as opposed to paint and bling...just my humble opinion..

Undead_Edsel_59 · LONDON, ONT

fatchuk wrote:
For that heavy of a car, I would not even consider manual brakes. She would be a tiring day driving with no brakes..disc brakes will work much better with a booster ,,The set u have described is a cobblers brake and I doubt the proportioning valve would work as you would need to install pressure vales to inline to keep the rears from passing you .. also being a licensed wrench I would not likely safety that set up..With the disc set up from the 79 you should not have much trouble finding a master, booster, proportion valve set up in almost any wrecking yard or somebody on here most likely has a parts car ..I am pretty sure most of that stuff could easily be found I think most stuff from a crownVic, Marquis , or several other Fords up till the ninties would be a better way to go cheaper, easier to source new stuff .. In the interest of building a safe car why even mess with that old mixed crap..just seems to me safety should be that most important part of building a car would be safety as opposed to paint and bling...just my humble opinion..

I work in the wrecking yard. So finding that stuff is not a problem... But what the problem is, I can't find a booster that will fit between my hood hinge and Engine. I have the original treadle Vac booster and master, that came with the car. But it's seized, and would cost me over 400 to rebuild. There is also a aftermarket set up I can buy designed for my car. But its a fair chunk of change too. I do work at the wreckers, So I don't make huge amounts of money. Or I already would have gone and bought the brand new aftermarket one.

A lot of these Edsel's came with a one line manual master cylinder, so I figured a two liner would be a step ahead. The AMC master bolted right in and hooked up to the brake pedal no problem. With tons of room for brake arm travel. That's why I ended using it.

Moobster · NORFOLK COUNTY, ONT

Could you use hydraboost instead of a vacuum booster??? They're quite small and found on many trucks.

Undead_Edsel_59 · LONDON, ONT

I had thought about that too.

54vicky · OAKVILLE, ONT

if you were closer I have treadle vac you could have I stole a few pieces off.I don't remember what I took off but it was bolt on stuff you could take off yours.been so long ago I may not have taken anything off may have been in my mind to use something off it.if you peddle down on a bike you will save on gas biggrin biggrin the offer has no expiry date

Undead_Edsel_59 · LONDON, ONT

54vicky wrote:
if you were closer I have treadle vac you could have I stole a few pieces off.I don't remember what I took off but it was bolt on stuff you could take off yours.been so long ago I may not have taken anything off may have been in my mind to use something off it.if you peddle down on a bike you will save on gasthe offer has no expiry date

According to google 1h 35min drive.. not to to far away.

I'll keep that in mind. Thanks, I appreciate the offer.

fatchuk · ST MARYS, ONTARIO

I should get your e-mail..I have some info ..lots of reading?learning..I have learned that org old TVS booster was a dangerous system, if the seal between the master and booster went and they often did, it would suck that master dry quicker than Linda Lovelace and you got zip for brakes..I found a couple guys that have replaced the TVS using a master /booster from a mid to late 80s Honda civic and utilizing the remote fill with a little modification to pedal ratio from 1:1 increase it 3:1 but I think he stayed with drum brakes just added power drum brakes.. Anyway I did find some interesting reading as that is a new conversion to me so I found it interesting..There is a lot of info about it. I also found a few guys who have done it differently using a booster from an 85 LTD and a master cyl from an 87 Econoline.. I just haven't been able to confirm the safe success..It is an oddball conversion for sure or maybe I should say challenging Should be interesting to do but a worthy upgrade if you plan to make it a driver ..

parklane · St THOMAS, ONT

I also have a 86/87 Gr.Marque that has 65,km that you can steal as much as you need off of it.

slim · DUNDAS, ONT

The braking system don't care if its boost or manual as long as it can build the required pressure. Your problem is that the original vac boost pedal ratio will be 3.5 or 4:1 to get to the same place you will need at least 6.2:1 and chances are there isn't room to modify the existing unit. This is the watered down simplified explanation. You will be better off spending a bit of money and pick up a kit that is matched . Speedway sells them for a reasonable price. Pm Glenn ( cat in the hat) he has used a few .

Undead_Edsel_59 · LONDON, ONT

Wow, Good thing I asked. Did not know it was going to be that complicated. I know I can buy a reman 59 Edsel manual master cylinder over the border for about $70. And I know a junkyard I can get the proper brake pedal for manual brakes, right out of a 59 Edsel. Maybe for now I'll redo the factory drums, And do the conversion at a later date. trying to get the mechanical done as cheap as possible.
And If I use oem parts, at least I will know everything will do what it needs to.

Thanks for the Info guys

slim · DUNDAS, ONT

If you can compare the two you might be ok . Drum / drum is a different animal and will require less pressure and flow. they may of changed the master and slave size to compensate for the difference back then . Hard to say without comparing both systems

Undead_Edsel_59 · LONDON, ONT

Have been doing some research tonight. A factory Edsel Manual brake cyl bore is, .65625. The Edsel power brake cyl is 1.125. The AMC Master I have on the car now is, .9449 . Would you think the AMC master would work ok for Drum/Drum set up?

I will figure out the pedal ratio tomorrow.

(also the T-Bird uses a 1" bore master)

slim · DUNDAS, ONT

To give you an idea of what the diameter relates to in final pressure at a 1:1 ratio .... .6562.... 21/32 at 100 pounds force =257.6 psi the AMC is 24mm and I don't feel like covering so will call it 15/16 at the same 100 pounds=144.3 PSI so maybe 150 at 24 mm the 11/8. ....1.125 works out to 100.6 PSI. By what your saying I think you will find the pedal ratio between the boost and manual the same. to convert to manual I wouldn't go bigger then 3/4 bore =226 psi if you could find the original 21/32 even better. If you run a single can just make sure you have a working E brake and keep it in working order. came across this you might find it useful

http://www.aarnio.com/edsel-fi/elli58/elli-mpc.htm

Undead_Edsel_59 · LONDON, ONT

Ok, thanks for the info. I will buy the correct master. I can get a new one in the states for around $75. Also thanks for the link. That page will be very useful.

Undead_Edsel_59 · LONDON, ONT

Ok, just did some measuring and my brake pedal is 5:1 ratio (pivot point to push rod 2". Push rod to centre of foot pad 10")

-5:1 ratio

-24mm bore, master

-The t-bird callipers have a 3 3/32" bore

-- Edited by Undead_Edsel_59 on Friday 29th of May 2015 06:16:29 PM

slim · DUNDAS, ONT

Pressure would be marginal for drum bit over 700 psi . for that size of car you would want a minimal of 1200 psi for disk

RacerRick · TORONTO, ONT

For that combo, its iffy.

The large pistons on the T-bird calipers will give a lot of clamping force, so you may not need the full 1200psi to generate adequate brake torque.

There is a bunch of math you can do to figure out if you have enough stopping force.

www.engineeringinspiration.co.uk/brakecalcs.html

I would find out what size master cylinder a t-bird or similar car that used the same calipers with manual brakes used. If manual brakes was not offered, its probably because the large caliper pistons require enough fluid that for manual brakes, a master cylinder with a small enough bore, but long enough stroke was never offered.