Master for 4-Wheel Disk

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Master for 4-Wheel Disk

April 25, 2007, 01:12:52 PM

I’m having trouble finding a Master Cylinder to work for my setup.
I have 91 Mustang front disks and 84 Mark VII rear disks.
Cobra master is what I have been looking for yet my parts man can’t find it, I just got off the phone with Max at 5-star ford and he tells me they have been discontinued and are “no longer available”.
I hit the U-Pull-It yesterday looking for something that might work and came up empty.

Any Ideas what I could use?

Master for 4-Wheel Disk

Reply #1 – April 25, 2007, 01:26:51 PM

What about an 86 SVO m/c($20 reman) or a 94-98 v-6 mustang? They both should bolt up to your booster.

louie

Master for 4-Wheel Disk

Reply #2 – April 25, 2007, 01:45:02 PM

Got it covered, not that cheep however but found the cobra master at Disk Brakes Are Us for 89,, total $99 shipped. It's on the way.

Master for 4-Wheel Disk

Reply #3 – April 25, 2007, 02:27:38 PM

Advance Auto has new Bendix MC for 93 cobras for $67, and reman Raybestos for $68. This is where I got my Cobra MC and BB.

Master for 4-Wheel Disk

Reply #4 – April 25, 2007, 02:31:13 PM

Is that $67 with or without the core charge? (I'm thinking without)

Is that a '93 Cobra master cylinder that you got? Those seem a bit small for four wheel disc to me, with only a 1" bore. I had a 1" bore MC on my car initially after converting to vac assisted brakes and I didn't like it, although I also put 73mm front calipers on the car too.

Master for 4-Wheel Disk

Reply #5 – April 25, 2007, 04:33:16 PM

I spoke to Jeff at Disk-Brakes-Are-Us and they have both the 93 cobra w/1" bore and a 94-95 cobra 15/16" bore same price. Told him my setup and the 94-95 15/16” bore is what he recommended, so that’s what I went with. I was thinking the 1” sounded better but he said it’s not.
I dident question it anymore than that, I'm assuming he knows what he's doing after all Disk Brakes are them. (could easly be my downfall when it doesent work, I'll let ya know)

Master for 4-Wheel Disk

Reply #6 – April 25, 2007, 06:56:57 PM

I bought my '93 Cobra M/C off eBay for $65 plus $15 shipping. This was with no core charge.

RedLX - why would a '93 Cobra M/C be too small for disc brakes? I've got pretty much the exact brake setup in my car (11" front discs, 11" vented TC rear discs) that a '93 Cobra had. I haven't actually driven the car yet with this setup, but the pedal feels fine just during the bleeding process.

Master for 4-Wheel Disk

Reply #7 – April 25, 2007, 11:00:23 PM

Quote from: Red_LX;142750

with only a 1" bore.

This was my thoughts also, Actually I thought i read someplace about a 1-1/8 bore. However in that same thread it mentioned the travel available can have more to do with it than the stroke.

Also, from WAY Back in my memory (15-20 years ago) dealing with Hydraulics when I dropped a built 351W and 4 speed top loader with a competition clutch in a 53 Ford half ton. I couldn't compress the clutch, was solid as a rock like it was stuck. Contacted a Hydraulic specialist and he suggested getting a smaller more master OR a larger bore slave. He suggested 1/16 smaller on the master saying this would increase the pressure to the slave by a phenomenal amount (THOUSANDS of PSI) sure enough 1/16 changed the peddle from feeling like the rod was stuck to pushing so easy I didn't even think it was working.

Amazing stuff these Hydraulics

Master for 4-Wheel Disk

Reply #8 – April 26, 2007, 09:09:05 AM

I read about that 1-1/8 bore also (SVO master cylinder) and the article recommended against using it, saying the big bore was too big for what I did (stock [for Mustang] 11" front brakes and TC rear). They recommended the 93 Cobra M/C with the 94-99 V6 M/C coming in second

Master for 4-Wheel Disk

Reply #9 – April 26, 2007, 10:13:23 AM

There are a few MC larger than 1"
http://mjbobbitt.home.comcast.net/mustang/mc.html

Master for 4-Wheel Disk

Reply #10 – April 26, 2007, 10:37:45 AM

See, the thing between a clutch and a brake system though...in a clutch you you have one master cylinder moving one slave cylinder. In a brake system, you have one master cylinder moving FOUR slave cylinders.

I don't claim to be an expert in hydraulics by any mean, but in that situation I think the volume of fluid moved by the master plays a factor, rather than pressure.

I just know that when I used that 1" bore master, I had a mushy pedal. When I switched to the SVO master, it firmed it up a bit (though it is still a tad mushy for some reason)

Master for 4-Wheel Disk

Reply #11 – April 26, 2007, 12:41:15 PM

GREAT info 88Sportcoupe Thanks.

After reading that info, have you ever tried swapping out your booster Red LX?

Master for 4-Wheel Disk

Reply #12 – April 26, 2007, 02:49:20 PM

No. Didn't much feel like doing that job again if I don't absolutely have to.