Do I need a new Master Cylinder with 73MM calipers?

oo7thenova

Founding Member
Aug 31, 2001
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CALIFORNIA
My stock Calipers are leaking from the piston and I'm try to buy replacements for them

Do I need a new Master Cylinder with 73MM calipers?
Also if i get the 73mm calipers, do Brake pads that would go on stock 5.0 Calipers Fit in the 73mm Ones??

thanks
 
You don't need a MC, but it is Highly Recomended for safety concerns (your pedal might drop to the floor under heavy braking)

You can reuse your stock pads on the new caliper, you just have to spread the pins on the back of the pads so they don't move in the piston, be careful not to break them, because they are fragile, even though they are metal
 
BlackFox5.0 said:
You don't need a MC, but it is Highly Recomended for safety concerns (your pedal might drop to the floor under heavy braking)

You can reuse your stock pads on the new caliper, you just have to spread the pins on the back of the pads so they don't move in the piston, be careful not to break them, because they are fragile, even though they are metal

That is a good suggestion! NOT. "You dont need one, but the braking system does not work without a larger bore unit!" Great advice!

You have to upgrade the MC to a larger bore unit. Bottom line. If you want the math, post back.
 
:OT:
Can I install the Summit(Wilwood) brake partition valve on a completely stock system and just leave the valve wide open?

What will happen if I use the larger MC on a completely stock system?

I'm doing the conversion, but I might have to do it piece by piece.

Thanks guys.
 
Now IM concerned, I have the 73mm Calipers with slotted and c/d rotors using the stock M/C. Which one should I get as an upgraded part. Do you have a part# or any suggetions that will help 007the nova and myself? Let me know.
 
Matt90GT said:
That is a good suggestion! NOT. "You dont need one, but the braking system does not work without a larger bore unit!" Great advice!

You have to upgrade the MC to a larger bore unit. Bottom line. If you want the math, post back.

Could you please send me the "math" Because I'm not understanding the advise that's being passed around on this thread. I'm currently running a pair of 73MM SVO Calipers up front with Hawk HPS pads and MM Brake Caliper Sleeves with absolutely NO problems? I drive approx 20miles to work which is basically in the mountains with some serious twisties. I get on the brakes pretty hard on the way down and have yet to have any problems :shrug: The only complaint I have is the Hawk pads squeal like a stuck pig when they are cold :rlaugh:
 
I have the entire SVO brake package on my car. 76mm calipers, SVO M/C, and the rear axles, disks and calipers. I think the SVO M/C is reccomended for the bigger calipers. It works well on my car anyway.

However, if you keep the rear drum brakes I think you have to add the Proportioning valve. Not sure though... but it's a good idea for tuning the brake bias anyway.
 
Saleen put the SVO master cylinder on the Fox bodies with the 76mm SVO calipers. Are you saying Saleen doesn't know what they are doing? Or are you saying the SVO M/C is better for 76mm fronts with disk brakes too?

Also, Saleen didn't put a proportioning valve on my car and it's fine. However, they did switch the block that distributes brake power.
 
Saleen used rear discs, if they did use the SVO MC, and 73mm Calipers, Depending on the size of the calipers in the back, a bigger MC is better for bigger calipers, They might have just used all SVO brakes I think, as well as a proper Prop Valve for rear discs
 
The SVO M/C is the way to go. You won't need an adjustable proportioning valve. While you are at it, get the stainless steel caliper pin sleeves to replace the rubber. Take it from someone who has done this! The stock M/C is 1" bore, the SVO is 1 -1/8" bore. Doesn't sound like much of a difference but it works great. I tried the stock first and it felt like four-wheel drums. You can stop but what's the point? To build up your leg? Get the bigger M/C! I also have the slotted/cross-drilled rotors.
Good luck,
Mikey
 
The SVO MC is too BIG! I had stock drums, and the 73mm Calipers up front, I put in my SVO MC and I couldn't even lock up the brakes even if I jammed the pedal till I lifted out of my seat. I told you which ones you want. the stock MC is smaller than 1"
 
The SVO MC should only be used if you have front AND rear brakes from an SVO

I would use the 94-98 v6/gt mc or the '93 cobra mc.

Also, adjustable prop valve do not come on cars from the factory. It's a liability. Imagine someone who has no idea about anything to do with braking systems messing around with that knob. They dial in too much rear bais and first rainstorm they spin the car. Saleens put a proportioning valve in their cars much like SVO's. Is it the same one exactly? who knows.
 
Quote: "Saleens put a proportioning valve in their cars much like SVO's"

Not true. Saleen gutted the stock combination block (ie. stock prop. valve) but they did NOT add an adjustable prop. valve to the set-up. They did however use the SVO M/C (or Lincoln Mark VII M/C....same thing) with a 1 1/8" bore. Brake booster remained stock.
 
89 Saleen#455 said:
Not true. Saleen gutted the stock combination block (ie. stock prop. valve) but they did NOT add an adjustable prop. valve to the set-up. They did however use the SVO M/C (or Lincoln Mark VII M/C....same thing) with a 1 1/8" bore. Brake booster remained stock.


So what controls the brake bias? I had the same brake setup on my car previously and with the adjustable valve open all the way i would always lock the rears up first. Something needs to step it down. :shrug:
 
People crack me up..."the SVO is way too big so use a 93 Cobra m/c" Checking specs....SVO is 1-1/8" bore....93 Cobra is 1-1/8" Yeah....I guess you should go with the 93 Cobra <snicker> It's the new math they teach ya! At least he's right on the stock 86 bore, it's .827"

Mustang5L5 has a point, the SVO is set up for having rear disks. I haven't had any problems and I drive an hour each way to work in the mountains of California. Brakes are kick'n for a stock daily driver. If your car is not stock, I would definitely upgrade the entire system to something else.