Questions on Cobra brake swap

gunnerdog · 10-21-2009, 12:17 PM

Ok I decided to take the plunge and go cobra brakes front and rear and the parts start ariving today. I previously had power front disc from the factory on my 69. Do I need to change out my master cylinder or distribution block? Any advice is very welcome. Thanks

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chillininnh · 10-21-2009, 05:33 PM

You will need to swap your disc/drum master for a disc/disc master. I would swap the factory distribution block for an adjustable proportioning valve.

gunnerdog · 10-21-2009, 06:01 PM

Will any disc/disc master cylinder bolt up to my booster? So dump the MC, and the distro block for new. I guess the SSBC is a good one or is there a better deal out there?

chillininnh · 10-21-2009, 06:06 PM

I would get in touch with Shaun at Streetortrack.com, he is VERY knowledgeable and can help steer you to the best choice/product. Chockostang.com is also a great source. Good luck!!!!

http://www.chockostangclassicmustang.com/

http://www.streetortrack.com/

sixt5 · 10-21-2009, 06:38 PM

MAKE SURE YOU GET THE RIGHT MASTER!! my master is the incorrect bore and will NOT lock the brakes up. in have 13" disc/ drum setup and the drums wont lock. barely will hold with my line lock.

CAD · 10-21-2009, 07:30 PM

I think I read somwhere that a master and booster off of a 94/95 disc/disc V8 mustang will work but I'm not sure.

sixt5 · 10-21-2009, 08:16 PM

im wanting to go hydroboost

Scott H. · 10-21-2009, 10:37 PM

Quote:

Originally Posted by chillininnh

I would get in touch with Shaun at Streetortrack.com, he is VERY knowledgeable and can help steer you to the best choice/product. Chockostang.com is also a great source. Good luck!!!!

http://www.chockostangclassicmustang.com/

http://www.streetortrack.com/

(IMO) Good advice.
You can also use the '86 - '87 SVO Mustang master cylinder, but it's not a simple "bolt on". It requires matching the booster pushrod length correctly. The length and adjustment of this rod are critical items. If you've never done this, I'd recommend finding someone to help you who really understands brakes.

The Cobra brake setup requires a 1" bore with a bias of 60/40. Disc / drum master cylinders are 65/35 so after going through the trouble to remove the residual valve, there is not quite enough volume to the rear calipers to get the balance correct. I've tried this with an adjustable proportioning valve, and even with the valve fully biased to the rear, it's just a tad short of being correct. Good but not great braking. I ended up doing some custom work to get a disc / drum master cylinder to work.

On a side note:
If you haven't all ready bought your kits, talk to Shaun about his front Cobra kit with the deeper rotor hat. The stock Cobra rotor really limits your wheel choice. The rims on the '66 below are custom to fit the stock dimensions of the Cobra rotors.
I have the Mustang Steve kit up front, which is a very nice and complete kit, but uses the stock Cobra rotors. Shaun at Street or Track has both styles of kits.

When you get these brakes set up correctly they really work awsome. I have this setup on the car in the signature below. There is some information on the website in the signature as well.

Good luck!

Silverblade · 10-22-2009, 12:04 AM

can you elaborate on limited front wheels choice? you can still go deep dish rear right?

Scott H. · 10-22-2009, 12:12 AM

Rear wheel choice is not a problem, only the fronts due to the shallow hat on the rotor. The front caliper sits out further than the wheel mounting surface.
Street or Track offers a different caliper bracket and rotor that sets the caliper further in. This allows using pretty much any 17" wheel.