front disc conversion

7173Mustangs.com

Help Support 7173Mustangs.com:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

fonzogt25

Well-known member
Joined
Jul 2, 2014
Messages
84
Reaction score
0
Location
mi
My Car
1973 mach 1 w/ 1971 351c
So i found a guy that would sell me his fromt disc spindles and calipers for about 200 bucks. They are off a 73 mustang. My question is will they fit mine? I have a 73 mustang with drums in the front but i believe they are the smaller tires. Would i have to get bigger rims to fit the disc brakes? And also if my tires are big enough to house the discs, would they just bolt up to my suspension?

Thanks!

EDIT: he said the brakes were stock size on 14 inch wheels

 
Last edited by a moderator:
My '71 H-Code Mach 1 came with factory power disc brakes, and 14" wheels. Stock 14" steel wheels from the day are a crap-shoot as to which will fit over the calipers and which will not. My car came to me wearing 14" chrome modular rims, so I don't have any P/Ns to offer on the stock steel wheels.

What I do know is that not all old school stock steel wheels are created the same. The ones from my pal's drum-brake equipped '63.5 Galaxie 500 do not fit over the calipers.

So to answer your questions:

Yes - you will most likely want to get bigger rims (& tires, of course) because your drum brake rims may not fit over the calipers.

Yes - the spindles will bolt-in to replace your drum brake spindles.

Yes - once the spindles are changed, your can effectively becomes a disc-brake car, as far as your suspension and wheels are concerned. But - you will need to change out the master cylinder and proportioning valve for disc brake units, since the drum brake components work differently.

There are some good threads on this site regarding drum-to-disc conversions - use the Custom Search Tool in the upper right-hand corner to narrow them down. ::thumb::

 
No unfortunately i dont have a friend i can test fit the tires. Ok, does anyone know what the space needed inside my rim would be to check if itd fit?

 
Your wheels will fit. I've done the conversion. Like another said get the brake things also. You will also need rubber lines, the steel lines and the landing bracket between them. I believe the pedel assembly was different also when power.

 
Last edited by a moderator:
Alright. Sounds good. Now whats the difference between manual and power brakes?

Also why cant i use the same master cylinder and proportioning valve as my drum brakes?

 
Alright. Sounds good. Now whats the difference between manual and power brakes?

Also why cant i use the same master cylinder and proportioning valve as my drum brakes?
You can use the same master cylinder. My car was drum manual brakes and I swapped to disc brakes and retained the original manual master cylinder and proportioning valve. I have been running these for several years with no issues. Your hard lines in front will remain the same and can be reused, you will just need to buy the disc brake rubber hoses.

 
Understood, I just assumed we were talking about a complete " like factory" conversion. With the drum master cylinder there will likely be some fluid delivery issues and dragging pads that will cause heat build up and subsequent spongy brakes. So they will probably work. But I'd do more research about the different designs.

 
Last edited by a moderator:
Ok. Well let me ask you guys the worth of these spindles and rotors. He is asking 200 for those. Both have been sand blasted and POR-15. Are these worth 200? Is the stopping power of the discs vs rotors worth paying the 200 or are they worth less than that?

 
I don't recall what I paid for mine - probably got them from ebay (and somehow managed to forget to add them to my spreadsheet). But I think that's a good deal, considering the asking price from reputable vendors... providing they're in good shape.

For instance: http://www.mustangsunlimited.com/itemdy00.asp?T1=TC22+01 $349.95 for the pair.

 
So i found a guy that would sell me his fromt disc spindles and calipers for about 200 bucks. They are off a 73 mustang. My question is will they fit mine? I have a 73 mustang with drums in the front but i believe they are the smaller tires. Would i have to get bigger rims to fit the disc brakes? And also if my tires are big enough to house the discs, would they just bolt up to my suspension?

Thanks!

EDIT: he said the brakes were stock size on 14 inch wheels
So you are going to have to get the rotors so factor in that cost. Expect to pay around $60.00 each for a quality one.

 
You need the backing plates to protect the disc.

The master cylinder on the drum brakes has a 1" diameter piston and the disc is .937" diameter. The proportioning valve allows a different amount of pressure to go to the brakes. Yes if will probably work with the drum brake one but it will not work correctly. You should get everything to do the job right. There are no adjusters on disc brakes so you cannot balance the front to back by adjusting the calipers. In a panic stop situation the proportioning valve does the work. If your fronts lock up then you will spin out in a panic stop.

I am also told, but have not done the change, that a Granada disc brake is a direct bolt on with 11" discs. I think you might have to change the tie rod end to get the pin to lock in to the Granada. Not sure what years but think 78 is one year.

I have a complete set on a 72 parts car but no time to pull them off right now. I will be putting up for sale later. Need to be able to move the car around and don't want to pull now.

Do it right and you won't regret it do it wrong and you will have problems.

David

 
I get around 350.00 for all the parts for a conversion - depends on condition.

spindles with calipers - complete, booster and MC, pedal and prop valve + shipping

Don

 
Don's deal is the way to go you get everything you need to do a great job. To everyone with disc brakes. If the calipers are dragging check the front hoses going to the calipers. If you let the caliper hang there by the hose while doing a brake job it can cause the inside of the hose to delaminate and cause flow issues and might need replacing. If they are original I would replace unless you need them for show.

David

 
I did the swap from manual drum to power disk. It required I change many parts. The brake pedal is different from manual to power, the master cyl. You will need a power booster, a different proportion valve, and different rubber hoses. I replaced my hard lines as well. The hard lines did not match up with the master cyl or the proportion valve. I installed new disks and pads and rebuilt calipers. Great news is the car stops great. The brake pedal difference was a shock. The manual braked have a longer stroke with more leverage.

Sent from my iPad using Tapatalk


4b5507bdc02fcdf90a710aa03d5fc0ab.jpg


Sent from my iPad using Tapatalk


d572d36c5930d981abb36ba1649a0696.jpg


Sent from my iPad using Tapatalk

 
Last edited by a moderator:
Back
Top