The 1996 Ford Windstar 4-wheel disc MC has a 1.00" bore, large reservoir and (3) 10mm x 1.00 bubble flare ports. (2) of the ports exit on the left side and one port exits downward at the front end of the MC's body. You can plug the bottom port with a 10mm x 1.0 bubble flare plug or, if you don't have a brake switch mounted on the brake pedal you could possibly install a pressure-activated switch in the 3rd port.

The Windstar MC is around 8-1/8" long. It will fit in a '65/'66 Mustang with a 2.3L Fox vacuum booster but, it's too long to mount on a 5.0L Fox booster (drivers shock tower will be in the way). The Windstar MC will clear an Export brace, if you have one installed.







A 1995 Explorer 4-wheel disc MC is a very close cousin of the ('94-'98) SN95 V6 Mustang 4-wheel disc MC. It's roughly the same 7-1/2" in length, has the same 'level' plastic reservoir (as compared to the sloping reservoir of the Cobra MC) , and it has the same 1-1/16" bore as the '94-'98 V6 Mustang. --the '99-2004 V6 Mustang MC swithced to a slightly smaller 1.00" bore. Unlike the SN95 MC though, the Explorer MC has ports that exit on the left.

This is a comparison of an Explorer MC (very similar to the Mustang V6 MC) next to a Windstar MC.







 

I don't know of any Ford MC (with a horizontal flange pattern) that won't fit within the engine bay confines of an early Mustang, when using a thinner Fox 2.3L brake booster. With a thicker 5.0L Fox booster, the length of the MC does matter because of the shock tower.

The '67-'70 Midland/Ross or Bendix brake boosters, dimensionally, are very close to the same size as the Fox 5.0L boosters. This means MC lengths do matter.

If you have 4-wheel disc brakes, running a '70 MC may work but, it isn't going to function like it should. 'Working' and 'working correctly' aren't necessarily the same thing. The early Mustang (disc brake) MCs are designed for discs/drums, --not discs/discs. 

A disc/drum MC is not going to displace the same amount of brake fluid to all four wheels, per pedal application, in the same proportions as a disc/disc MC will. 

Each of the primary and secondary pistons of the MC have (at least) two seals per piston. The distance (and volume) between each of the two seals dispenses a given amount of fluid as you are pushing down on the pedal to apply the brakes. You can think of it as two syringes simultaneously having the plunger pushed in at the same rate but the two syringes displaces a different amount of cc's. 

The photo below shows (3) different MCs: Mk VII/SVO 4-wheel disc MC on the left, '87-'93 disc/drum MC at top right, and an SN95 Mustang V6 4-wheel disc MC at bottom right. Notice the differences in distance between the seals of the primary and seconday pistons for each.

Last edited by ultrastang (3/04/2014 9:53 PM)

I also looked into that Windstar master cylinder, but it has a 1.0625" bore.  When I had that size on my 66, the line pressure, even with the Fox booster, was not enough to actuate my 4 wheel COBRA discs.

I changed to using all 1" bore master cylinders and the brakes feel much better.

That Windstar unit would be great to use if you were using the 5.0 Fox booster or 67-70 Midland or Bendix booster because those boosters have dual diaphragms and apply more force to the MC.  I had one on a 66 using the 5.0 Fox booster.  It would clear the shock tower OK, but a Shelby export brace was a requirement, as was removal of the original welded braces on the shock towers where the original braces bolted on.  The Shelby brace mounts higher on the shock towers so it clears better.

Ultra... Have you measured that Windstar MC at 1.0" bore?  Everything in the published data says it is 1.0625", no matter which engine you have or whether it has anti-lock brakes or not.

MustangSteve wrote:

I also looked into that Windstar master cylinder, but it has a 1.0625" bore.  When I had that size on my 66, the line pressure, even with the Fox booster, was not enough to actuate my 4 wheel COBRA discs.

I changed to using all 1" bore master cylinders and the brakes feel much better.

That Windstar unit would be great to use if you were using the 5.0 Fox booster or 67-70 Midland or Bendix booster because those boosters have dual diaphragms and apply more force to the MC.  I had one on a 66 using the 5.0 Fox booster.  It would clear the shock tower OK, but a Shelby export brace was a requirement, as was removal of the original welded braces on the shock towers where the original braces bolted on.  The Shelby brace mounts higher on the shock towers so it clears better.

Ultra... Have you measured that Windstar MC at 1.0" bore?  Everything in the published data says it is 1.0625", no matter which engine you have or whether it has anti-lock brakes or not.

 
Hmmm.... It's been some years ago that I decided to experiment with the Windstar 4-wheel disc MC to see if it would work in an older Mustang, with a 4-wheel disc brake conversion, and what boosters it would/would not fit on, due to the shock tower limitation. I was searching through a MC catalog (at that time) at a local parts store and came across a listing for a full-up (complete new assembly) Windstar MC with reservoir, 10mm ports, and a 1.00" bore. Off hand, I don't know what the part number was for the unit I bought at the time.

It's also been too long since I looked through all this and I'm not certain but, I think '96 was the first year for this style MC in the Windstars. In doing a brief search just now on O'Reilly's site, I see that the '96s spec'd at a 1-1/16" bore. I jumped ahead to the listing for a '98 and found a reman one with no reservoir that listed it as having a 1.00" bore. I also spotted listings for some that had (2) 12mm ports and one port with a 3/8" port.

The Winstar MC I installed on a friend's '65 Mustang was supposed to be a 1.00" bore and had (2) 10mm ports on the left side of the body. I put a plug in the bottom port of the MC but in looking back, I can't remember if the port was metric or if it was an SAE threaded port. --it's just been too long ago to remember all the exact details of what I used.

At any rate, here is a listing for a ('98) Windstar MC body, which lists it as having a 1.00" diameter bore. So, evidently, I wasn't dreaming there was a listing for a Windstar MC with a 1.00" bore.   

http://m.oreillyauto.com/mt/www.oreillyauto.com/site/c/detail/OBH3/102876/01292.oap?year=1998&make=Ford&model=Windstar&vi=1304648&ck=Search_01292_1304648_787&pt=01292&ppt=C0066

I put a MK VII ms in my 68 and it would not stop the car with any authority, it has a 1.125 bore and the line pressures were well below operating standards.
 I happily ended up using a stock 68 disk/drum O/E ms with my disk disk set up using MK VII rear disks.

The bottom port on the 96 Windstar master cylinder is 3/8-24  inverted flare.  The side ports are both metric bubble flare.  I toyed with the idea of putting one of these master cylinders on the Galaxie.  The only way I could do it was with an adaptor to 1/8 pipe thread.   If someone now makes a 3/8-24 inverted flare pressure switch, that would be a clean installation.  

Last edited by Greg B (10/02/2015 7:45 PM)

67StangMan wrote:

MustangSteve wrote:

That Windstar unit would be great to use if you were using the 5.0 Fox booster or 67-70 Midland or Bendix booster because those boosters have dual diaphragms and apply more force to the MC.

The Midland 67-70 booster is a single diaphragm unit. They were not offered in dual diaphragm.  I know...I'm considering switching from my single diaphram 1967 Midland to a dual diaphragm unit.

The 1996 Winstar MC is in fact 1 1/16" bore (1.0625).  I've been running one for years and measured it myself when I inspected it prior to use.

I'm considering a 1 1/8" bore MC for my 4 wheel disc setup. Need one with ports opposite engine side and no residual valves.  And I prefer a reasonably priced Ford unit, but I might consider the C3 Vette MC if I have to. Any recommendations?

 

The thicker Midland and Bendix boosters are dual diaphragm according to all published specs.  Typically the shape of a dual diaphragm booster is the longer, smaller diameter like those two. The thinner boosters are single.  I have not disassembled one to check, but I have heard "dual diaphragm" on these for many years of dealing with Mustangs.  You said you know they are single.  Educate me, please.
 

MustangSteve wrote:

67StangMan wrote:

MustangSteve wrote:

That Windstar unit would be great to use if you were using the 5.0 Fox booster or 67-70 Midland or Bendix booster because those boosters have dual diaphragms and apply more force to the MC.

The Midland 67-70 booster is a single diaphragm unit. They were not offered in dual diaphragm.  I know...I'm considering switching from my single diaphram 1967 Midland to a dual diaphragm unit.

 

The thicker Midland and Bendix boosters are dual diaphragm according to all published specs.  Typically the shape of a dual diaphragm booster is the longer, smaller diameter like those two. The thinner boosters are single.  I have not disassembled one to check, but I have heard "dual diaphragm" on these for many years of dealing with Mustangs.  You said you know they are single.  Educate me, please.
 

I have a diagam of the Midland single diaphragm '67-'70 Mustang booster and will scan and post here shortly.
My Midland booster is single diaphragm and is exactly 7" in diameter.  It is 6" from firewall mounting surface to MC mounting surface (inclusing the spacer/breather thingy). What other diameter sizes were offered for the '67 - '70 Mustang Midland boosters? Perhaps a larger diameter, dual diaphragm booster was available as an option? I haven't seen one but would like to.
 

I am using the 92 Ranger MC on my 66 with four wheel Cobra discs.  Works great and has 1" bore with ports on driver side.  It is not a true four wheel disc master cylinder, though.  Not sure of the exact internal differences.

As Steve posted above, he's using that MC with his 4-disc set up without issues.....take the plunge....

67StangMan wrote:

The Midland 67-70 booster is a single diaphragm unit. They were not offered in dual diaphragm.  I know...I'm considering switching from my single diaphram 1967 Midland to a dual diaphragm unit. 

Well, I was mistaken!  I studied the '67-'69 Midland booster diagram I have and it does show dual diaphragms. Here's the '67-'69 Midland booster diagram. Note: The firewall mounting bracket is not shown.

 

Last edited by 67StangMan (10/15/2015 11:28 AM)

This is a comparison of an Explorer MC (very similar to the Mustang V6 MC) next to a Windstar MC.




Anyone know what the measurement is of the Windstar MC mounting flange holes, C/L to C/L?  And what's the stock Mustang MC measurement?  Are they different?