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Upgrade Brakes - advice please

B

blackford

Member
Here is what I have now:

Kelsey Hayes discs up front with RS-2 pads (10 year old pads recently resurfaced)
Granada 10x2 drums in back with RS-2 shoes (10 year old shoes recently resurfaced)
Cobra Automotive 1" Aluminum dual master cylinder (no booster)

These brakes were an upgrade from the stock drums all around and the brakes performed well with the RS-2 pads even at the road course nearby as recently as 2006.

The master cylinder has always been a bit of a mismatch for manual brakes because you have to apply more foot pressure although you have less travel.

Nowadays, the brakes just don't seem to work as well anymore. I resurfaced the pads and shoes and serviced the drums and rotors, but things really didn't get much better. I also tried adjusting the proportioning valve to see if that would help. Maybe the pads and shoes are just too old and resurfacing them isn't going to help...not sure.

I've known for a while that I have to do a redo on the brakes. I want to upgrade the front discs to something better than Kelsey Hayes and put discs on the rear.

If I should change out the MC for a smaller bore MC than i'll do that too.

I would like to add a power booster if there is a unit that would fit my '65, but I don't know if I have room especially since I have a hydraulic clutch for my T5z in the vicinity of the MC.

I'd like to hear your recommendations for new brakes on my car. I like the idea of the Cobra 13" disks up front along with MustangSteves kit, but i'm open to what you guys think. I have 17x8 wheels all around.
 
Change to a 3/4" master to reduce your pedal force if you'd like. You'll obviously gain some travel but this is the size I have used and most others do as well. Make this change and you won't feel the need for a booster.

13" is a BIG rotor. Our light cars do not need that much brake (on the street anyway). All you gain is more weight and since you go to the strip not sure that's a good thing. I suggest a smaller rotor and aluminum calipers. You can save weight and gain stopping power out back same way. Wilwood makes kits for both that aren't too expensive and look and function great.
 
"Horseplay" said:
Change to a 3/4" master to reduce your pedal force if you'd like. You'll obviously gain some travel but this is the size I have used and most others do as well. Make this change and you won't feel the need for a booster.
Click to expand...

That would be great if that would make the difference. If I leave the KH discs in front and add discs in the back, is the 3/4" master still the proper size?
 
"blackford" said:
"Horseplay" said:
Change to a 3/4" master to reduce your pedal force if you'd like. You'll obviously gain some travel but this is the size I have used and most others do as well. Make this change and you won't feel the need for a booster.
Click to expand...

That would be great if that would make the difference. If I leave the KH discs in front and add discs in the back, is the 3/4" master still the proper size?
Click to expand...
A few things factor in like going from drum to disc in back. A few years ago I spoke at length with a guy by the name of Dean Oshiro at a place called HotrodsUSA. If you do an internet search on him you'll find he is regarded as the guru of braking. He guided me in putting my latest system together and took the time to explain a hundred times more than I ever wanted to know about brake systems and function. What I suggested to you is the basics of what he told me.
The short answer to your question of going to a 3/4" MC being the correct size is yes. I have some pretty big calipers up front and the standard Wilwood out back and Dean assured me 3/4" is the way I wanted to go. As he put it, once a system is filled with fluid and bled, in a street application there is not a whole lot of fluid volume needed to actuate everything.
 
what MC has a 3/4" bore?
I have a 67 drum/drum MC with I believe a 1" bore and Granada/Versailles 4 wheels disc brakes with no booster. Pedal effort is more than PB but not bad and travel is decent but not too much. It's been this set-up for over 20 years and works good but if I could improve I'd be open to an upgrade.
The MC's Street and Track list have a 1", 1 1/16" or 1 5/16" bore.
 
Now that I got up off my butt and went out to the garage I have to apologize. It's not 3/4" but rather 1". The 3/4" is for my clutch. Sorry. 1" is the smaller option for a dual MC although Wilwood does make a 7/8" which would reduce effort a bit more.
 
Tracy,

Before you go and start spending money, take the car out and re-bed the brakes as if you were going to track the car. If you have track type pads/shoes and you don't get them up to temp, crap builds up and reduces the braking power.

I have always liked my brake setup on the track and the street. Since I switched to full race pads/shoes (Porterfield R4), the braking on the street is nowhere near what it'll do when up to track temps.
 
"Horseplay" said:
Now that I got up off my butt and went out to the garage I have to apologize. It's not 3/4" but rather 1". The 3/4" is for my clutch. Sorry. 1" is the smaller option for a dual MC although Wilwood does make a 7/8" which would reduce effort a bit more.
Click to expand...
thanks, I have heard the smaller bore will help with effort and was thinking I had about the smallest I could find. But that was like I said, over 20 years ago! Things change every decade or so... :whis
 
FWIW, I've got the parts to change mine over to PB. Plan is to use a 99-up V6 master cylinder and v-8 fox body booster. I'll have granada rotors with PBR calipers and Explorer discs out back. Now that I type this, I've got a hodge podge :hide

Bill
 
"tarafied1" said:
what are PBR calipers? I didn't know Pabst Blue Ribbon made brakes too :hmm
Click to expand...

Just pop a top Pop's. You know Coors is my brand. PBR is the aluminum 2 piston calipers off 99-04 4.6 2v stangs.

Bill
 
cool, I have one of those 99 4.6 2v Stangs :hmm but I better not take the brakes off of it :bomb

I like Killians Red, Sam Adams, etc... not that watery stuff
 
"tarafied1" said:
cool, I have one of those 99 4.6 2v Stangs :hmm but I better not take the brakes off of it :bomb

I like Killians Red, Sam Adams, etc... not that watery stuff
Click to expand...

PBR is an Aussie company that is also in the USA making Brake parts.
They make the brakes on the ZO6 corvette.
Here they are in the USA - http://www.pbrbrakes.com/
When we were young and irresponsible we used to use their VH44 booster on our old cars as it could be mounted remotely - like this
DSC01069.jpg

There must be a remote booster floating around America somewhere that could go in the unboosted cars.
 
"blackford" said:
What do you think of using this Wilwood master cylinder? It has a 7/8 bore and 2:1 reservoir volume ratio. I assume the larger reservoir is used for the front discs since they have more surface area than the rear drum pistons.

http://www.mustangsplus.com/xcart/Ford-Mustang-Wilwood-Polished-Aluminum-Tandem-Master-Cylinder-7-8-Bore.html
Click to expand...
That was the other size option I had when my system was put together. I chose the 1" for less travel over more pedal effort.
 
"Fst Blk" said:
FWIW, I've got the parts to change mine over to PB. Plan is to use a 99-up V6 master cylinder and v-8 fox body booster. I'll have granada rotors with PBR calipers and Explorer discs out back. Now that I type this, I've got a hodge podge :hide

Bill
Click to expand...

I have the same master cylinder 15/16" diameter (which I believe is also used on the cobras) same booster and calipers (PBR/Cobra) , but with 13" front and 11.6 rear disks. I like the pedal feel...

Don't forget, part of the feel also has to do with how far the master cylinder rod is mounted from the brake pedal's pivot point.
 
"stangg" said:
"Fst Blk" said:
FWIW, I've got the parts to change mine over to PB. Plan is to use a 99-up V6 master cylinder and v-8 fox body booster. I'll have granada rotors with PBR calipers and Explorer discs out back. Now that I type this, I've got a hodge podge :hide

Bill
Click to expand...

I have the same master cylinder 15/16" diameter (which I believe is also used on the cobras) same booster and calipers (PBR/Cobra) , but with 13" front and 11.6 rear disks. I like the pedal feel...

Don't forget, part of the feel also has to do with how far the master cylinder rod is mounted from the brake pedal's pivot point.
Click to expand...

That's something I haven't begun to work out yet. Any notes on where you mounted the pivot on the pedal?

Bill
 
AS a first step, like msell66, is was going to suggest bleeding. I would also consider changing the fluid.

Sizing of the master is very important. Sizing not only includes the bore of the master but matching the volume of the master to the volume required by the calipers as well as the force applied. Not to mention the geometry of the pedal to master. A few years ago while troubleshooting I made a spreadsheet you could plug in this information to help optimize all of this. I have no idea what I have done with it. If I find it I will add it to this thread.

Great info here:

http://www.pirate4x4.com/tech/billavist ... Hydraulics

http://www.outlawdiscbrakes.com/faq.html

http://www.engineeringinspiration.co.uk/brakecalcs.html
 
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