Brake questions

[brushwolf]

Have a few brake questions. Car is a 57 convertible. Swapped in 1971 Mark 3 disk brakes and spindles which have the same tie rod hole taper as 57, unlike Granada spindles. Apparently not a popular swap cuz the parts cost are triple what Granada parts are, but they bolt right on. Also cannot use stock 14" wheels, but intend on using Keystone Classics in 15 or 16 inch anyway..

Rear is stock 57 cop car drum brakes 3.55:1 ratio and was all rebuilt years ago, but I am going to replace the rear wheel cylinders again, since it has been sitting dry for 25 years. I have an adjustable proportioning valve to moderate the brake fluid flow to the rear.

1. Appears 57 rear wheel cylinders are available in 7/8 and 15/16 diameter.  I am guessing the smaller wheel cylinder would exert more rear braking with a given pedal travel, since it would require more fluid volume to move the larger wheel cylinder the same distance... Were the larger wheel cylinders for retractables and wagons, or what?

Since the car has front disks now, is it best to use the smaller diameter rear wheel cylinder, or the larger one?

2. I had saved the rear emergency brake cables off the 4 door cop car, cuz they were in very good shape and planned on using them, but perhaps the convertible and retractable rear cables are different somehow than a sedan cuz the parking brake mechanism on the X-frame convertible crossmember is different than a sedan.

That true?

3. Years ago, I also rebuilt the brake/clutch pedal hanger bracket with the intent of just having manual brakes with front disks. Later I changed my mind when I got a well preserved 58 parts car that had power brakes.  So, I swapped the power brake pedal arm and under dash booster from the 58 to the 57 hanger.  Had a years long search looking for a NOS "Swift Sure" manual transmission brake pedal and pad (narrow), but finally found one. 

I still prefer not to hang a booster on the firewall if I can avoid it, but think I read somewhere that the small diameter under dash booster has a very low assist rate, even with the separate reserve vacuum tank. I have a Granada power brake master cylinder, but am wondering if a smaller diameter manual brake master cylinder would help the pedal effort needed. Have had other hobbiests posit that their disk brakes work just fine without any booster at all, by using a smaller diameter brake master cylinder.

Suggestions for master cylinder that might work best with the factory booster, but drum brakes replaced with disks up front?
Or will I have to swap brake pedal arm once again and either go with a firewall mounted booster, or manual brakes?

4. From some long forgotten source, I was once told that the firewall should be reinforced where the master cylinder mounts, as it tends to flex on heavy braking. Not sure if that just applied to manual brakes, or not..

True, or overkill?

Thanks again, Mike

[brushwolf]

After reading many threads and perusing some online auto parts suppliers, I have confirmed that the park brake cables are indeed unique to retractable and convertible and the larger 15/16 rear wheel cylinders were indeed for wagons and retractables.

Keeping in mind that it is best to have matched parts in the braking system and starting from the point that I have the Lincoln calipers installed, I looked up the master cylinder bore for the Lincoln and it is 1". The 71 Lincoln had drum rear brakes and the bore of the wheel cylinders is 15/16, same as the retractable/wagon.

So, I ordered the brake cables and the retractable rear wheel cylinders since they are the same size bore as the Lincoln rear wheel cylinders were (0.9375). The brake line pressure should roughly match the balance of the Lincoln between front and back brakes at minimum. And I have the adjustable proportioning valve if the rear brakes lock up too easy.

I found a multitude of threads that affirm that a smaller bore master cylinder will indeed decrease pedal effort, but will increase pedal travel as well.  So, I looked up the Granada master cylinder bore and it is 0.937"  (0.063" smaller than the Lincoln master..).

Although my stock booster undoubtedly has much less assist capability than the Lincoln booster, it should still provide some assist.  Although probably still requiring more foot pressure than typical power brakes, it should still require less foot pressure than manual brakes (hopefully). And I don't really care for touchy brakes, any more than a real hard pedal.

Not sure about the pivot point on the brake pedal arm between the Ford power brake pedal arm and the Lincoln pedal arm, cuz the Lincoln is long gone now, but I would guess using a 71 Lincoln master cylinder would result in a very hard pedal with my dinky booster.

So, I am still inclined to try the Granada master cylinder. Although it will have more travel than the factory matching Lincoln master cylinder would, the fact that all the brake parts are new and the rear shoes will be adjusted to close tolerance, I am thinking this is the way to go and if it does not work, then it is back to the drawing board...

Anybody tried this before (disc brakes with only the factory booster, either with or without a reduction in master cylinder bore) ?

[KULTULZ]

If a true 57 POLICE rear, they had a unique size rear shoe. The wheel cylinder size is (was) spec'd to match the shoe size (front and rear) to hopefully obtain true balanced vehicle braking.

When you throw in a front disc conversion, all of that goes out the window and balance has to be achieved hopefully with valving (front metering/rear proportioning).

Be advised a so-called ADJUSTABLE PROPORTIONING VALVE is not the same as a true brake proportioning valve and is for brake bias control only. Most of your more reputable brake vendors (kit) will somewhere have a disclaimer that it is not meant for street use and is not DOT CERTIFIED. Their use is drag car only.

I like what you are doing (thinking outside of the box). I do not know the line pressure a 57 KH booster will produce. I will check the 57 SPECIFICATIONS booklet and see, but usually those figures were not released.

If it was me (and the shoe size/wheel cyl dia are the same or close - 57 and 71) I would source the MARK MC and proportioning valve (actually a COMBINATION VALVE that year). It will also have the METERING VALVE and a PRESSURE BALANCE VALVE included. The late sixties MUST and later GRANADA will work also. When you go and try to cipher fluid dynamics, you need one of those fancy COLLEGE DEGREES.

Let me know.

I have temporarily lost my LM MPC but will be glad to help you in any way.

[dgasman]

My Ranchero has the sure swift power brake with disc brakes and it works great for the type of power brake system it is . The assist rate is not like a more modern power booster but I like the feel it?s a good balance between over power or non power. You will need to use a master cylinder with 1 1/8 inch bore . The pedal ratio of the sure swift requires the larger master. If you use a smaller bore the pedal will feel like there is air in the brake lines , the pedal may go all the way to the floor as they have a very low pedal height to start with , a very spungy pedal and it will not stop right.

[brushwolf]

My Ranchero has the sure swift power brake with disc brakes and it works great for the type of power brake system it is . The assist rate is not like a more modern power booster but I like the feel it?s a good balance between over power or non power. You will need to use a master cylinder with 1 1/8 inch bore . The pedal ratio of the sure swift requires the larger master. If you use a smaller bore the pedal will feel like there is air in the brake lines , the pedal may go all the way to the floor as they have a very low pedal height to start with , a very spungy pedal and it will not stop right.

Yes the available pedal travel on the power brake arm concerns me.  I am curious as to what front calipers you have. I am guessing it is not Lincoln and is probably Granada or perhaps a GM metric caliper if it was a swap kit. 

Good to know yours works like I guessed it might (some assist, but not "touchy" either).  But that it even works on a 1 1/8" mc is good to know. Any issues with firewall flex?

I am wondering if the likely larger fluid capacity of the Lincoln calipers and the caliper piston size would effect the combination in some way. Would think so, but 1 1/8 is even bigger than the Lincoln at one inch. Do you know your caliper piston diameter?

Thanks,  Mike

[brushwolf]

Also, do you know what car your master cylinder and proportioning valve are from?

[dgasman]

Yes I have Granada disc?s  on the Ranchero and using a Granada proportion valve . The master is from a SVO Mustang from around  86 , bolts right on and no firewall flex . I have been running this setup for close to 20 years and never had a problem.

On my wagon I had the sure swift on it and it has 71 ford Ltd station wagon brakes front and rear with no problems . Now it has a mustang hydro booster and different pedal assembly . The wagon also is using the Granada proportion valve

[brushwolf]

If a true 57 POLICE rear, they had a unique size rear shoe. The wheel cylinder size is (was) spec'd to match the shoe size (front and rear) to hopefully obtain true balanced vehicle braking.

When you throw in a front disc conversion, all of that goes out the window and balance has to be achieved hopefully with valving (front metering/rear proportioning).

Be advised a so-called ADJUSTABLE PROPORTIONING VALVE is not the same as a true brake proportioning valve and is for brake bias control only. Most of your more reputable brake vendors (kit) will somewhere have a disclaimer that it is not meant for street use and is not DOT CERTIFIED. Their use is drag car only.

I like what you are doing (thinking outside of the box). I do not know the line pressure a 57 KH booster will produce. I will check the 57 SPECIFICATIONS booklet and see, but usually those figures were not released.

If it was me (and the shoe size/wheel cyl dia are the same or close - 57 and 71) I would source the MARK MC and proportioning valve (actually a COMBINATION VALVE that year). It will also have the METERING VALVE and a PRESSURE BALANCE VALVE included. The late sixties MUST and later GRANADA will work also. When you go and try to cipher fluid dynamics, you need one of those fancy COLLEGE DEGREES.

Let me know.

I have temporarily lost my LM MPC but will be glad to help you in any way.

Yes, it was an actual California cop car that I got the rear from, even had holes cut in front fender for spotlight and holes in trunk floor, interior floor and firewall that had big aftermarket wiring/cabling grommets still in place. Apparently part of the police radio had been in the trunk and wiring run under the floorboards. But, I dont know if it was the original rear axle for sure.

Even though Lincoln wheel cylinders are the same size as the retractable (and perhaps cop cars) wheel cylinders, I doubt the shoes were as large in diameter or width as the Lincoln 9 3/8" rear, or even if was the original cop car rear.  But, as you say when the disk brakes were added, it no longer was all in balance anyway...

Wish I had kept the booster and proportioning valve from one of the two 1971 Lincolns I parted, but don't think I did. Will go through the parts storage semi trailer just in case I did. There may be one from a 76 Torino in there too, even if there is none from a Lincoln. But, I can just buy a new Lincoln proportioning valve on a worst case basis.

So, it looks like the smaller bore Granada master is out of the plan and and either the matching Lincoln master or an even larger bore 1 1/8" master as dgasman replied is the modified plan.  If I use the Lincoln combination valve, is it likely I may still need the adjustable valve as well, or won't know until the car is rolling again?

Thanks, Mike

[RICH MUISE]

Have you considered changing the rears to disc as well? I'm well aware that the drums are adequate, but if you're planning on running wide tires in the back, rotors are easier to get that wheel/tire over than drums. I mention that because you're at the point in your build where what you do now can affect what you want down the road. Aside from the change to rear discs, 5/8  or 3/4 off the housing on each side, change to '56 shocks, all add up to making easy tire changes not possible without.
Just to add some more clutter to the discussion, I am running Granadas up front, 88(?) T-Bird conversion kit in the back(I think by Stainless Steel Brakes), and a '02 Mustang Cobra hydroboost/master. All Ford except the proportioning valve is Wilwood. I'm really happy with everything, but I really have nothing to compare it to, and I've never had to do a total panic stop at speed. It just drives/stops like my dailies. The '02 Mustang master has the larger (1 1/8?), but for reference, I was told the earlier ones were smaller. The downside to the hydroboost is the plumbing, bleeding, and they are ugly, and definitely don't look oem if that's your goal being a convertible.
I have a hard time believing there is a flex problem with the firewall since the bracket/brace the master/booster attaches to is attached to the dash and is quite rigid and heavy. I think I remember there also being another brace up there somewhere.
Do the police rears have trac-loc? Not even sure when Ford started the trac-loc..... 57??

[gasman826]

1969
1969 was the first year for the Ford Traction-Lok differential. From 1968-back, a locking Ford differential would have been the Equalok Limited-Slip which is not as good a differential as the improved Traction-Lok.Sep 2, 2014

1969 F100 rear axle - The FORDification.com Forums

[59meteor]

I believe the Equa Lok first came out in 59, it was pretty much garbage, I installed a fresh Equa Lok in my 70 Mustang back in 1976, by the end of the first weekend at the dragstrip, on street tires, it was only spinning one tire again, and shortly afterwards, it broke a spider gear. EquaLok did not have any coil springs for preload, just a concave Belville spring, and 2 or 3 clutch plates. Every Equa Lok I even seen was also only a 2 spider gear unit, the Traction Lok was better, but still far from good. They were available with 4 spider gears, and 4 small coil springs for preload, but like any clutch style limited slip for a 9 inch (or 8 inch), the rear pinion gear support bearing means that there is not room for clutches on both sides, like every other clutch style unit. Also to fit the few clutches into that one case halve, means they had to carve out the inside to make room for the splined clutch hub and clutch plates, which weakened the case. Very common to find Traction loks with the clutch side case broken around the ring gear bolts. Thats why I have a 31 spline Detroit Locker in my 59, Too many slipping and broken Trac Loks over the years.  As far as braking, on my 59, I have Wilwood front discs with 4 piston aluminum calipers , and out back, I have Ford Explorer rear drums. They are 10" compared to the original 1"s, but the Explorers have at least the same surface area, as they are 2 1/2" wide, rather than 1 3/4". With the 10" drums, removing the rear wheels and tires is a breeze, even with 15x8" wheels with 275/60R15 tires. I didn`t want either a vacuum booster or Hydraboost hanging off the firewall, and possibly interfering with my 428s valve covers, so I am running manual brakes, and manual steering as well, which would allow a hydraboost anyhow. I am using a factory manual brake pedal, and a 15/16" bore master cylinder, meant for a 73 or 4 Maverick with manual discs. The car stops fine, with no more pedal effort than the original 4 wheel drums did. I do have an adjustable proportioning valve, but it is currently wide open, as I have had no issues with one end locking up prematurly. I have not had to do a serious panic stop yet, but it easily stops from a 100 MPH dragstrip pass with no issues. My understanding with a 57-59 Ford with either a FE or Y Block engine, there is not much room for a large diameter booster, and it seems the small 6 & 7" boosters just do not have enough "boost" to work very well on a fairly heavy car.

[KULTULZ]

So, it looks like the smaller bore Granada master is out of the plan and and either the matching Lincoln master or an even larger bore 1 1/8" master as dgasman replied is the modified plan.  If I use the Lincoln combination valve, is it likely I may still need the adjustable valve as well, or won't know until the car is rolling again?

Another factor you need to consider is the caliper swept volume determined by the caliper piston size. The 71 MARK MC and calipers are calibrated to one another so that problem is more or less solved.

The MARK had 11 x 2 1/4' rear shoes while the 57 SW 9" (incl POLICE) had 11 x 2". So the 15/16" wheel cylinders should be correct.

You cannot use a fixed PPV and an adjustable PPV together. Most likely, the MARK valve (with a rebuild or NOS) will give you somewhat correct brake balance without taking vehicle weights into consideration.

If you still had the MARK, you could gauge the line pressures and make decisions from there.

Consider some kit vendors offer(ed) a disc kit containing DELCO CALIPERS (incl possibly low-drag), a CORVETTE MC and a CHEVELLE PPV for a FORD can give you an idea of how it all could or could not work correctly. Only a skid pad test will verify if you are close. Sliding sideways through a traffic light on a wet surface is no fun.

But I think you are on the right path.

[brushwolf]

Have you considered changing the rears to disc as well? I'm well aware that the drums are adequate, but if you're planning on running wide tires in the back, rotors are easier to get that wheel/tire over than drums. I mention that because you're at the point in your build where what you do now can affect what you want down the road. Aside from the change to rear discs, 5/8  or 3/4 off the housing on each side, change to '56 shocks, all add up to making easy tire changes not possible without.
Just to add some more clutter to the discussion, I am running Granadas up front, 88(?) T-Bird conversion kit in the back(I think by Stainless Steel Brakes), and a '02 Mustang Cobra hydroboost/master. All Ford except the proportioning valve is Wilwood. I'm really happy with everything, but I really have nothing to compare it to, and I've never had to do a total panic stop at speed. It just drives/stops like my dailies. The '02 Mustang master has the larger (1 1/8?), but for reference, I was told the earlier ones were smaller. The downside to the hydroboost is the plumbing, bleeding, and they are ugly, and definitely don't look oem if that's your goal being a convertible.
I have a hard time believing there is a flex problem with the firewall since the bracket/brace the master/booster attaches to is attached to the dash and is quite rigid and heavy. I think I remember there also being another brace up there somewhere.
Do the police rears have trac-loc? Not even sure when Ford started the trac-loc..... 57??

That limited wheel clearance for wider tires has always been a bane on these. Car is up on blocks but I have some old G60-14's (9" tread width; 10" total width) currently on it, mounted on some also old but still shiny ET 5 spokes 8" wide.  Struggled to get those up there just to see how wide a tire would fit and liked the look so left them on.

Think I had to use a small bottle jack between spring and frame and still scuffed sidewalls on wheel lip pushing it in there. The 60 Impala I took the wheels off had room to spare. Only about half an inch clearance to wheel lip on the 57, so they would probably scrub taking corners as well. But, the width of the tries is satisfactory to me.

I don't think I want to reverse course as far as narrowing the axle, since I could just order wheels with a half inch to an inch greater offset toward the center and get it together faster.  Couple of inches clearance still on the inside with these wheels and tires..

But, I am mulling over the rear disk brake conversion kits now. As you point out that would make a big difference in getting the tire past the wheel lip and brake drum. The hydroboost I don't really care for the look or the added plumbing jobs, though they undoubtedly are functionally superior to what I have in mind.

I want to keep it simple and mostly original looking besides wheels and tires, maybe a 58 hood though, as that is what I had on another 57 convertible I bought w/o a motor for $40 back in 1968. Probably paint both a 57 and 58 hood when I get that far and put on whichever appeals to me at that point in time.

Otherwise pretty much all factory look on interior and exterior. May also use the cleaner-looking 58 Fairlane 500 rear bumper, but I have the 57 Fairlane 500 rear bumper as well. They always looked so darn bulky though... But, I guess I can do either and switch easily enough later if I don't like it.

Under the hood I will have a non-stock motor, but painted 57 312 red and keeping it simple with no serpentine belts, no AC needed cuz Minnesota and a convertible, no headers but using the bigger 400M exhaust manifolds which flow better than the 351c factory units. Aluminum intake, alternator instead of generator, electronic distributor instead of points, Flowcooler aluminum water pump instead of stock cast iron one. Have not decided on radiator yet. I have a good 1971 Mark 3 radiator that cooled sufficiently for a 10:1 compression 460 and looks like it might fit, but if not I will buy something aftermarket.

The motor is a 1970 351c probably backed by a T10 4 speed. I have a 62 and 63 T10 here, both good (though I have also hoarded several T85 3 speed OD's since the car was factory manual transmission).

Machinist/engine shop told me I would have to run a composite head gasket and bigger cam than I had planned for more valve overlap to bleed off a little dynamic compression cuz it was 10:1 stated compression motor (1970 only) from the factory. Probably dropped some vacuum with the bigger cam also, but I assume it is still more than enough for the little 57 KH accordian booster.

4th time I changed my mind on motors too: first a 312 built, that went in a 57 retractable, then a 460 built, went in a 73 mach clone, then another 312 built which is still on an engine stand all dolled up with TBird cast finned valve covers). But, at some point I have to stop changing the plan substantially or the car will never be off the blocks.

I am just about to re-drop the already refurbished rear axle and springs to finish the rear underbody cleaning, painting, seam sealing and undercoating. Have frame, front suspension, steering and body underside done from the firewall to rear axle now. Spent the last 6 weeks mostly under the car cleaning, grinding, rust removal and vacuuming sand from frame rails. Filthy job.

Also had to fix some novice torch butchery some PO had done in clearancing the X frame rear vertical bracing for exhaust pipes and then fabricating a new pair of parking brake cable brackets cuz one was gone and the other was badly twisted from car apparently hitting something solid underneath at speed (rock?, stump?, log?, curb?...idk).

Brackets on both sides were damaged and only partially below the scrub line of frame.  Must be a story behind that but idk what is is. Driving with flat tires? Duke Boys jumps? Went off a dead end road?  The heavy X frame even had some small front toward back grooves scratched in them, though only cosmetic damage given the heavy metal construction.

I have 57 hardtop, 57 and 58 sedan, plus several 58 retractable parts cars, but the parking brake cable brackets were all quite different. A 58 convertible parts car I have was probably the same bracket, but somebody took them both off along with the axle and springs before I got what remained of that car. So, a good day used in cutting, drilling, welding to make new parking brake cable brackets patterned off the damaged one and then attaching them to frame. 

The Explorer 10 inch drum mentioned by 59 Meteor would also probaby work to provide just enough extra space to slip the tires easily past the drum as well, while likely also allowing the factory 57 parking brake cables to still work as well, without creating another project modifying the factory parking brake cables to work with the disk setups. Decisions, decisions... Too many options.

[brushwolf]

I believe the Equa Lok first came out in 59, it was pretty much garbage, I installed a fresh Equa Lok in my 70 Mustang back in 1976, by the end of the first weekend at the dragstrip, on street tires, it was only spinning one tire again, and shortly afterwards, it broke a spider gear. EquaLok did not have any coil springs for preload, just a concave Belville spring, and 2 or 3 clutch plates. Every Equa Lok I even seen was also only a 2 spider gear unit, the Traction Lok was better, but still far from good. They were available with 4 spider gears, and 4 small coil springs for preload, but like any clutch style limited slip for a 9 inch (or 8 inch), the rear pinion gear support bearing means that there is not room for clutches on both sides, like every other clutch style unit. Also to fit the few clutches into that one case halve, means they had to carve out the inside to make room for the splined clutch hub and clutch plates, which weakened the case. Very common to find Traction loks with the clutch side case broken around the ring gear bolts. Thats why I have a 31 spline Detroit Locker in my 59, Too many slipping and broken Trac Loks over the years.  As far as braking, on my 59, I have Wilwood front discs with 4 piston aluminum calipers , and out back, I have Ford Explorer rear drums. They are 10" compared to the original 1"s, but the Explorers have at least the same surface area, as they are 2 1/2" wide, rather than 1 3/4". With the 10" drums, removing the rear wheels and tires is a breeze, even with 15x8" wheels with 275/60R15 tires. I didn`t want either a vacuum booster or Hydraboost hanging off the firewall, and possibly interfering with my 428s valve covers, so I am running manual brakes, and manual steering as well, which would allow a hydraboost anyhow. I am using a factory manual brake pedal, and a 15/16" bore master cylinder, meant for a 73 or 4 Maverick with manual discs. The car stops fine, with no more pedal effort than the original 4 wheel drums did. I do have an adjustable proportioning valve, but it is currently wide open, as I have had no issues with one end locking up prematurly. I have not had to do a serious panic stop yet, but it easily stops from a 100 MPH dragstrip pass with no issues. My understanding with a 57-59 Ford with either a FE or Y Block engine, there is not much room for a large diameter booster, and it seems the small 6 & 7" boosters just do not have enough "boost" to work very well on a fairly heavy car.

Are you running the original 59 nine inch rear with (what year?) Explorer drums and backing plates, or the 8.8 Explorer narrowed on one side posi axle? If the 9 inch, then I assume that the Explorer backing plates are offset more toward center of car to accommodate the extra width of the drum?

Thanks, Mike

[59meteor]

The rearend in my 59 is a 9" that I bought years ago from a 58 Edsel Citation. Since the 58 "hi line" Edsels were based on Mercury, rather than Ford chassis, that 9" was a couple of inches wider than a 57-59 Ford, and also had the 5 or 5" bolt pattern. My buddy narrowed the Edsel housing about 3/4"narrower than the original, and installed the "new style" Torino ends, and we ordered new 31 spline aftermarket axles of the correct lengths. Not sure exactly what year the Explorer I took the brakes from, but it was the older style with the 8.8 solid axle, and drum brakes, rather than the later versions with rear discs, and even later used IRS. Yes, I do believe the backing plates are deeper than the originals, the backing plates are less than an inch from the leaf springs. And the original emergency brake cables from the stock rearend fit perfectly into the Explorer backing plates and work great with the 10" brakes.