disc brake conversion

[Joe Johnston]

You can't run disc brakes with just a master cylinder and no booster. Disc brakes need a lot more pressure to work correctly than drum brakes. Plus you need a dual master cylinder and prop valve to equalize the pressure.

Weren't some Mustangs and Granadas originally available with non-power disk brakes??

I have non-power disks on my 57 and NO proportioning valve as the master is sized for the front disks and rear cylinders. System works great, and yes the pedal effort is higher than if it had a booster.

Don't want to start anything, just sayin'...................

Did a bit of Googling just to confirm my fading memory from driving these cars back in the day.

Mustangs had non power disc brakes available until 1971.
65-66 was only available as non power disc.
At least 74 Mavericks also had non power discs.

[jopizz]

I've never heard of non-power disc brakes and I've been around a pretty long time. I don't believe manufacturers would put boosters in if they could do it without them. It's interesting that you can run discs without a booster. Of course the weight of the car has a lot to do with it. I've thought about trying it but smarter people than me have said it's not possible.

John

[kenneybert]

I don't know. Will the longer bolt bottom out before it seals? SUMMIT should offer a full selection.

Did the kit vendor recommend a banjo fitting or is this something that you have designed?

Parts List for conversion:

two 1975 to 1980 Ford Grenada spindles
two 1975 to 1980 Ford Grenada backing plates
two 1975 to 1980 Ford Grenada wheel bearings
two 1975 to 1980 Ford Grenada calipers Wagner part 890 and 891
two 1975 to 1980 Ford Grenada rotors Wagner part 522
one 1975 to 1980 Ford Grenada proportioning valve
one 1975 to 1980 Ford Grenada master cylinder
two Banjo Bolts 7/16 inch - 24 thread, one-inch long
four copper washers 7/16 inch
two brake hoses NAPA part 36959
two anti-rattle clips NAPA part 82304
two sets disc brake pads Wagner part PD91 PD7027R....

this is on the main page of this website ..its not something i made up .. the banjo bolt says 7/16-24..one inch long .. summit racing says all they have is one and one eighth inch long bolt..

[jopizz]

That conversion was done quite a few years ago if I remember. Rick Nolen fails to mention anything in the instructions about what booster he is using. I can only guess that he used the original under hood booster that came on his squarebird. Those instructions are rather incomplete to say the least. Most of the people who have done the conversion lately use the scarebird brackets so they can use their stock spindles rather than mess with the Granada spindles.

John

[simplyconnected]

John is right.
Besides that, there is something really wrong with your Granada part numbers:
Wagner 890 & 891 are LIGHT BULBS!
Granada brake hoses come with threads, not banjo bolts. Check out Rock Auto's offerings:
I'm using Granada calipers on my '55 and they do not have banjo bolts, but they require copper washers to seal the joint.

S-10 calipers DO use banjo bolts (those are on our '59).

Whether you use Granada or (GM) S-10, your booster needs to be large enough for DISK brakes. OEM boosters back in 1960 were ok for shoe brakes but the braking system was sub-par for today's stopping distances. OEM boosters were 8" diameter. You need a two-stage 8" for disk brakes. The diameter stays the same but it extends farther. The difference in boost is double because disk brakes require much more pressure.

[kenneybert]

John is right.
Besides that, there is something really wrong with your Granada part numbers:
Wagner 890 & 891 are LIGHT BULBS!
Granada brake hoses come with threads, not banjo bolts. Check out Rock Auto's offerings:
I'm using Granada calipers on my '55 and they do not have banjo bolts, but they require copper washers to seal the joint.

S-10 calipers DO use banjo bolts (those are on our '59).

Whether you use Granada or (GM) S-10, your booster needs to be large enough for DISK brakes. OEM boosters back in 1960 were ok for shoe brakes but the braking system was sub-par for today's stopping distances. OEM boosters were 8" diameter. You need a two-stage 8" for disk brakes. The diameter stays the same but it extends farther. The difference in boost is double because disk brakes require much more pressure.

yep I should of done more research on it before going ahead and buying a ton of parts .....if i hadnt put a new interior in the car id part the thing out ,,, a guy that use to be a friend of mine says he has done a couple grenada over the years is why i went for it in the first place ... maybe ill just put all the original crap back on it and ship it ,, getting to ticked at it to even like it anymore ..

[jopizz]

Hopefully you'll get over the disc brake thing and appreciate your car for what it is. There are quite a few threads on here from members who have tried the conversion only to have it end in frustration. It's not for everyone. If you really like the car I would put it back to stock with all new brake components. I think you'll be surprised at how good the original drum brake performance is when all the parts are new. If you feel that you've sunk enough money in it and just want to get rid of it I can understand that also.

John

[simplyconnected]

yep I should of done more research on it before going ahead and buying a ton of parts .....if i hadnt put a new interior in the car id part the thing out ,,, a guy that use to be a friend of mine says he has done a couple grenada over the years is why i went for it in the first place ... maybe ill just put all the original crap back on it and ship it ,, getting to ticked at it to even like it anymore ..

Hold on a minute, Ken. You have to know that fabricating and restoring is **** hard to do. Disk brakes weren't offered for Ford cars until nearly fifteen years after ours were made. And of course, Ford never recommends mixing parts that weren't engineered for your specific model. Do I understand you are doing these retrofits to sell the car? If so, 'original equipment' brings the highest price; put the original parts back on and sell the car.

We retrofit disk brakes because we drive our cars in today's traffic. I can tell you first hand, that Granada spindles and disk brakes work wonderfully on Squarebirds (and many other old Ford cars). This work is not easy and you need to understand 'brake systems' very well.

I don't know what you bought but OEM Granada spindles need the lower hole widened with a TAPERED REAMER if you intend on using original ball joints from 1958-60 T-birds. This is what most guys do rather than buying smaller ball joints for a lighter car.

Everything you need to know is on our site including the new wheels you will need. Please understand, your original wheels won't fit, but Granada wheels will. These conversions were done in a variety of different ways but they all follow the same basic rules.

I suggest you research as much as you can before going into this. One 'thing' always leads to another. Most members keep their Squarebird and want the best performance which comes from new components. Since your ball joints will be separated, this is a good time to change the sway bar to a larger-diameter. It's also the best time to change urethane bushings, bumper stops, shocks and springs. Since both "A" arms will be removed, the bushings and ball joints can be serviced on the bench. Then, you can clean up and paint all the parts before re-assembly. Suspension work is not for the faint-hearted, it's bull work and potentially dangerous.

Restoring these old beauties is never a good investment, but it sure brings a lot of joy to the owner who is passionate about his personal luxury T-bird. That's what this site is all about. - Dave

[DKheld]

After restoring my entire original drum brake system (booster included) and driving the car for about a year then converting to front disc brakes using the Granada spindles I can tell you from experience there is a huge difference between all new 4 wheel drum brakes and front disc - rear drum systems on these heavy Tbirds.
The main reason I converted was to pull a small trailer for my son's wheelchair but besides less fade under load there were many other benefits including less maintenance, better wet stops (yes I drive my Tbird in the rain), less side to side pull, smoothness etc.

You should be able to add power assist to your standard non power brake system fairly easily assuming you do not have A/C (which would require the dreaded booster extension bracket made of unobtanium). The original Tbird booster and pedal assembly mounts to the bolts that currently hold your master cyl to the firewall. Send a PM to Carl Heller (partsetal) here on the forum or one of the other used parts suppliers and see if they have a booster pedal assembly for sale.

Make sure you get the pedal rod (bar) that connects the brake pedal to the booster assembly. This is the factory configuration and there won't be any worry with pedal height or getting an adjustable pedal rod to fit the brake pedal. That would take care of the pedal assembly - all bolt on and no mods needed.

Next - 2 choices. You can have the booster and pedal assembly shipped to Booster Dewy and rebuilt as well as having the booster face changed to the Lincoln 2 bolt style face to accept a modern 2 bolt style master cyl or do as Marcelo and cut the old booster off and add a newer style dual action booster to the original Ford booster bracket. Marcelo put the part numbers he used on his conversion in his thread. I have the original Tbird booster with my disc system and it is completely adequate.

Generally a disc system needs about 1000 psi of pressure to operate well and the standard old original 8 inch Ford booster adds 900 psi of boost to the 400 or so you get from the master cyl. I'm sure the dual action booster would be a much better option (probably 1800 psi of pressure) but would require a little more system modification to install. There is NOT a brake master cyl made for front disc and rear drum that fits the original booster face so you will either have to get it modified or use the replacement booster on the original pedal bracket.

Otherwise you can try the Galaxie bracket with the booster and master already installed. I tried it - seems I was going to have to drill an extra hole in the firewall and or galaxie bracket to make it mount to the existing bolts but my memory is a little cloudy on that since it was 10+ years ago. After finding Booster Dewy's modification that made the original system work - I opted to go that route and never looked back a the galaxie items. The adjustable pedal rods are available and would have to be used for the galaxie application. Some here have used the adjustable pedal rods so they may have a part number for the pedal rod that would have the necessary end to connect to your Ford style pedal. The galaxie bracket system available is probably the same system Dave Dare (simplyconnected) can supply you with (or give you the info on where to buy).

As I mentioned in my PM - the Granada flex lines for the front (shown in a previous post) are too short and are very close to the spring tower with those metal extensions they include - they won't work.

Here are the main items I used. This info is 10 years old so some of the places may be out of business. The hoses didn't fit like I wanted them to so I trimmed a bit off the edge of the caliper to give the hose a downward angle to keep it as far away from the spring tower as possible.

Master Power Brakes
1) VL3350 Combination valve for disc/drum systems
1) HS88520K hose kit '16 inch for GM 69-77 single piston caliper

Baker Precision Products
2) 150/977522 Banjo bolts with washers 7/16-24 01/04
the invoice does not mention how long they were but you should be able to measure your caliper bolt depth and the hose end width to see if the 1 or 1 1/8 banjo bolts will work.

One set of Granada spindles from a local junk yard plus machine work at Fat Man Fabrication

Unknown sources but most likely NAPA, Advance Auto or O'Riley.
1) 10-1518 Master Cyl
1) 4000 - left front Granada caliper
1) 4001 - right front Granada caliper
2) 5670098 - Granada rotors (1976) (Advance Auto)

plus a bunch of miscellaneous lines and fittings.

I don't see where you mentioned it but I guess you are aware that you have to split the hydraulic system - right now it is a single low pressure drum system and you need to split it front to back. I did it at the junction on the frame where the master cyl line goes. I ran new lines to each front wheel and added the brake light switch in the rear system by moving it down to this junction point and extending the wires to the switch.

Installing the spindles was the easiest part of the whole conversion. Alignment is a nightmare unless you can find a really good shop willing to work with you on tweaking the settings (one really good reason to go with the Scarebird brackets). I plan on getting my settings recorded and will post them for future reference but will have to get my engine changed this winter before I can get to the alignment shop - blew out the rear main seal a few months back.

Eric
"Failure is not an option" - unless there are no other options - heh heh


Same dimensions for the pedal bracket booster extension and master cyl bolts (red lines)
rivets that will release the booster from the pedal bracket (yellow circles) - ask Marcelo - he's done it

[kenneybert]

After restoring my entire original drum brake system (booster included) and driving the car for about a year then converting to front disc brakes using the Granada spindles I can tell you from experience there is a huge difference between all new 4 wheel drum brakes and front disc - rear drum systems on these heavy Tbirds.
The main reason I converted was to pull a small trailer for my son's wheelchair but besides less fade under load there were many other benefits including less maintenance, better wet stops (yes I drive my Tbird in the rain), less side to side pull, smoothness etc.

You should be able to add power assist to your standard non power brake system fairly easily assuming you do not have A/C (which would require the dreaded booster extension bracket made of unobtanium). The original Tbird booster and pedal assembly mounts to the bolts that currently hold your master cyl to the firewall. Send a PM to Carl Heller (partsetal) here on the forum or one of the other used parts suppliers and see if they have a booster pedal assembly for sale.

Make sure you get the pedal rod (bar) that connects the brake pedal to the booster assembly. This is the factory configuration and there won't be any worry with pedal height or getting an adjustable pedal rod to fit the brake pedal. That would take care of the pedal assembly - all bolt on and no mods needed.

Next - 2 choices. You can have the booster and pedal assembly shipped to Booster Dewy and rebuilt as well as having the booster face changed to the Lincoln 2 bolt style face to accept a modern 2 bolt style master cyl or do as Marcelo and cut the old booster off and add a newer style dual action booster to the original Ford booster bracket. Marcelo put the part numbers he used on his conversion in his thread. I have the original Tbird booster with my disc system and it is completely adequate.

Generally a disc system needs about 1000 psi of pressure to operate well and the standard old original 8 inch Ford booster adds 900 psi of boost to the 400 or so you get from the master cyl. I'm sure the dual action booster would be a much better option (probably 1800 psi of pressure) but would require a little more system modification to install. There is NOT a brake master cyl made for front disc and rear drum that fits the original booster face so you will either have to get it modified or use the replacement booster on the original pedal bracket.

Otherwise you can try the Galaxie bracket with the booster and master already installed. I tried it - seems I was going to have to drill an extra hole in the firewall and or galaxie bracket to make it mount to the existing bolts but my memory is a little cloudy on that since it was 10+ years ago. After finding Booster Dewy's modification that made the original system work - I opted to go that route and never looked back a the galaxie items. The adjustable pedal rods are available and would have to be used for the galaxie application. Some here have used the adjustable pedal rods so they may have a part number for the pedal rod that would have the necessary end to connect to your Ford style pedal. The galaxie bracket system available is probably the same system Dave Dare (simplyconnected) can supply you with (or give you the info on where to buy).

As I mentioned in my PM - the Granada flex lines for the front (shown in a previous post) are too short and are very close to the spring tower with those metal extensions they include - they won't work.

Here are the main items I used. This info is 10 years old so some of the places may be out of business. The hoses didn't fit like I wanted them to so I trimmed a bit off the edge of the caliper to give the hose a downward angle to keep it as far away from the spring tower as possible.

Master Power Brakes
1) VL3350 Combination valve for disc/drum systems
1) HS88520K hose kit '16 inch for GM 69-77 single piston caliper

Baker Precision Products
2) 150/977522 Banjo bolts with washers 7/16-24 01/04
the invoice does not mention how long they were but you should be able to measure your caliper bolt depth and the hose end width to see if the 1 or 1 1/8 banjo bolts will work.

One set of Granada spindles from a local junk yard plus machine work at Fat Man Fabrication

Unknown sources but most likely NAPA, Advance Auto or O'Riley.
1) 10-1518 Master Cyl
1) 4000 - left front Granada caliper
1) 4001 - right front Granada caliper
2) 5670098 - Granada rotors (1976) (Advance Auto)

plus a bunch of miscellaneous lines and fittings.

I don't see where you mentioned it but I guess you are aware that you have to split the hydraulic system - right now it is a single low pressure drum system and you need to split it front to back. I did it at the junction on the frame where the master cyl line goes. I ran new lines to each front wheel and added the brake light switch in the rear system by moving it down to this junction point and extending the wires to the switch.

Installing the spindles was the easiest part of the whole conversion. Alignment is a nightmare unless you can find a really good shop willing to work with you on tweaking the settings (one really good reason to go with the Scarebird brackets). I plan on getting my settings recorded and will post them for future reference but will have to get my engine changed this winter before I can get to the alignment shop - blew out the rear main seal a few months back.

Eric
"Failure is not an option" - unless there are no other options - heh heh


Same dimensions for the pedal bracket booster extension and master cyl bolts (red lines)
rivets that will release the booster from the pedal bracket (yellow circles) - ask Marcelo - he's done it

yep as I mentioned before ,, I bought a 1977 grenada just for these parts ,, my 59 tbird has manual brakes ,,no booster and also no air conditioning ....im not going to give up on it I like my tbird to much to do that ,,i got to spring to get it done ,,ill get it to stop if i have to cut a hole in the floor and drag my dang feet ... just totally aggrevated to no end right now ...thought it was going to be an easy do with all the parts i had ,figured id have to make a bracket for the booster would be my hardest problem ...i done had the spindles reamed for the lower ball joints ,, bought the hoses and drilled them out to 7/16 to fit the banjo bolts .got what i think is everything except a bracket to make my grenada booster and mc work ,, which now i was told the grenada booster mc wont work .. ???? thanks for all your guys info ...greatly appreciated

[kenneybert]

Hold on a minute, Ken. You have to know that fabricating and restoring is **** hard to do. Disk brakes weren't offered for Ford cars until nearly fifteen years after ours were made. And of course, Ford never recommends mixing parts that weren't engineered for your specific model. Do I understand you are doing these retrofits to sell the car? If so, 'original equipment' brings the highest price; put the original parts back on and sell the car.

We retrofit disk brakes because we drive our cars in today's traffic. I can tell you first hand, that Granada spindles and disk brakes work wonderfully on Squarebirds (and many other old Ford cars). This work is not easy and you need to understand 'brake systems' very well.

I don't know what you bought but OEM Granada spindles need the lower hole widened with a TAPERED REAMER if you intend on using original ball joints from 1958-60 T-birds. This is what most guys do rather than buying smaller ball joints for a lighter car.

Everything you need to know is on our site including the new wheels you will need. Please understand, your original wheels won't fit, but Granada wheels will. These conversions were done in a variety of different ways but they all follow the same basic rules.

I suggest you research as much as you can before going into this. One 'thing' always leads to another. Most members keep their Squarebird and want the best performance which comes from new components. Since your ball joints will be separated, this is a good time to change the sway bar to a larger-diameter. It's also the best time to change urethane bushings, bumper stops, shocks and springs. Since both "A" arms will be removed, the bushings and ball joints can be serviced on the bench. Then, you can clean up and paint all the parts before re-assembly. Suspension work is not for the faint-hearted, it's bull work and potentially dangerous.

Restoring these old beauties is never a good investment, but it sure brings a lot of joy to the owner who is passionate about his personal luxury T-bird. That's what this site is all about. - Dave

yep i have two 59 tbirds now both in pretty good shape one better than the other and ive had 3 other ones over the past 10 years so i do really like the looks of them,, this one i have now i really like cause ive spent a ton of money on ,,just wanted better brakes with the grenada swap .. like i said i bought a 77 grenada which was in great shape body wise and ran like a top ,,i took all the parts off it to do the brake job and bought what it didnt have like the rubber hoses banjo bolts,etc.. just got to figure how to make a booster and mc bracket .... thanks for all your help ,,,

[simplyconnected]

...just got to figure how to m ake a booster and mc bracket .... thanks for all your help ,,,

Eric and I both gave you a source for the OEM bracket. Get one soon or they will be gone. Right now, we have two guys trying to do a retrofit. I know of a couple more that planN on this change in the spring.

Now that you have altered your Granada calipers to accept banjo bolts, look for the longer Cadillac hoses. - Dave

[kenneybert]

Eric and I both gave you a source for the OEM bracket. Get one soon or they will be gone. Right now, we have two guys trying to do a retrofit. I know of a couple more that planN on this change in the spring.

Now that you have altered your Granada calipers to accept banjo bolts, look for the longer Cadillac hoses. - Dave

thanks I really appreciate all your guys info ,,this website is handy as a pocket on a shirt ...Ill git-r-dun this winter .. thanks ken

[kenneybert]

Eric and I both gave you a source for the OEM bracket. Get one soon or they will be gone. Right now, we have two guys trying to do a retrofit. I know of a couple more that planN on this change in the spring.

Now that you have altered your Granada calipers to accept banjo bolts, look for the longer Cadillac hoses. - Dave

talk to my old buddy in vermillion today ,, he says one of y'all called him a week or so ago ... hes a good ole boy isnt he? hes said he would fix me up with a m/c and booster tomorrow .. im gonna run over and see what hes got ,, he said he sold his place in north carolina and moved 35 more birds back to vermillion ..wants me to come over and take a look ,,if he will let me Ill take a picture of his empire ..ken

[kenneybert]

talk to my old buddy in vermillion today ,, he says one of y'all called him a week or so ago ... hes a good ole boy isnt he? hes said he would fix me up with a m/c and booster tomorrow .. im gonna run over and see what hes got ,, he said he sold his place in north carolina and moved 35 more birds back to vermillion ..wants me to come over and take a look ,,if he will let me Ill take a picture of his empire ..ken

I broke down and bought a booster m/c off ebay for 199 bucks and its on and done..it does look good if i say so myself ... thanks again for all the info..