Which master cylinder?

ClayBelt

Member
Feb 21, 2020
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Leon County, FL
I've got a 1986 SVO I just put a new brake booster in and am getting ready to put 03-04 Cobra front brakes on (via 95 spindles). I was told the 1 1/8" master cylinder will be too stiff, especially with braided stainless lines. Given that I would like to retain my stock booster if possible, what master cylinder should I use?
 
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Mustang5L5

i'm familiar with penetration
Mod Dude
Feb 18, 2001
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Try the 85 Town car 1” MC. It should be a direct bolt on for the SVO as they both use SAE thread pitch fittings.

The SN95 MCs are a little bit of a PITA to plumb is as they are metric thread so you will need to cut and flare
 

ClayBelt

Member
Feb 21, 2020
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Leon County, FL
So a 1” bore MC should give me an adequately firm brake pedal with the 40mm twin piston cobra calipers up front and 54mm SVO rear calipers? I do want it to be a little firm, just not too firm to use.
 

Mustang5L5

i'm familiar with penetration
Mod Dude
Feb 18, 2001
35,031
11,148
224
Massachusetts
SVO calipers are 8370mm^2 of piston surface area. 99-04 CObra calipers are 5152mm^2. Rear calipers are 4580mm^2 and remain constant.

SO swapping the SVO fronts to the cobra calipers is a 25% reduction in total surface area of all the calipers.

1 1/8" SVO is 638mm^2 of area. The 1" bore MC is 507mm^2. That;s a 20% reduction. That's as close as you are going to get.

1993 cobra, and 85 lincoln town car both have 1" bore MC's, but the town car MC will be an easier swap since it's SAE threads. However, the SVO MC might need an adapter since it appears one line is a different pitch. You might need to swap it with a standard GT line. Unfortunately i don't know this info completely, so you might have to do some legwork

 

ClayBelt

Member
Feb 21, 2020
63
6
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21
Leon County, FL
I managed to get ahold of some SVO owners who were running this style setup early this morning actually, seems a lot of them are continuing to use the SVO master cylinder. If that one feels too stiff for me though when I do my swap I’ll try the town car one.