Dual Bowl Master Cylinder...

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gravelman
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Dual Bowl Master Cylinder...

Post by gravelman »

"While I was there" with my brake job I was considering a double bowl GM style master cylinder. A friend of mine loaned me one and because of the diagonal fender brace it won't fit. Is the single bowl factory master cylinder our only choice? For safety reasons it would be a good upgrade.

Thanks,

Mitch
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redstangbob
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Re: Dual Bowl Master Cylinder...

Post by redstangbob »

I know this subject has been discussed all over this site, but it falls under the modified section, so I moved it accordingly. Good luck, Bob C
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gravelman
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Re: Dual Bowl Master Cylinder...

Post by gravelman »

Thanks Bob...
stubbie
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Re: Dual Bowl Master Cylinder...

Post by stubbie »

There is a more modern dual master cylinder sold by one of the vendors that you can use. It looks more like one you would find on a Toyota than a sixties Ford. You can use it without the brace modification. This is not it but the sort of thing I'm talking about.
http://www.ebay.com/itm/Premium-Master- ... kz&vxp=mtr

Other than that you could try a flat top from Willwood or do some mods on the brace.
http://ssbrakes.com/i-10092514-master-c ... 470-3.html
gravelman
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Re: Dual Bowl Master Cylinder...

Post by gravelman »

Thanks Stubbie,

The plastic Toyota as you suggest would be inappropriate in my engine bay, I'll get further information on the aluminum job, I'm not sure if it's compatible with a brake booster?

Mitch
mainstreetprod
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Re: Dual Bowl Master Cylinder...

Post by mainstreetprod »

I've already installed the one sold by Bob's. It is dual circuit but has one plastic reservoir and goes on the existing booster. I'm replacing the old proportioning valve with an adjustable one. Also noticed that most dual brake circuit schematics include metering valves, not sure if I need to install one or not. Still waiting for the main brake line to arrive.
stubbie
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Re: Dual Bowl Master Cylinder...

Post by stubbie »

Sorry gravelman that flat top was just an example. Couldn't find the one I was looking for. Try the Willwood web site for the correct one. Yes I agree on the Toyota look one. I think it would look out of place in an old Ford.
Mainstreetprod If you have front disks and rear drums or drums all round you should probably get a combination valve. They have a metering valve and proportioning valve built in. You can buy them for each system type.
mainstreetprod
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Re: Dual Bowl Master Cylinder...

Post by mainstreetprod »

stubbie wrote:Sorry gravelman that flat top was just an example. Couldn't find the one I was looking for. Try the Willwood web site for the correct one. Yes I agree on the Toyota look one. I think it would look out of place in an old Ford.
Mainstreetprod If you have front disks and rear drums or drums all round you should probably get a combination valve. They have a metering valve and proportioning valve built in. You can buy them for each system type.

Stubbie- I've been reading about combination valves but had already ordered an adjustable proportioning valve to replace the original. Mine is disc front/drum rear, is there no metering valve in the system or did the single master have one built in? If there was no metering valve originally why would I need one? Thanks in advance.
gravelman
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Re: Dual Bowl Master Cylinder...

Post by gravelman »

Stubbie,

I had the same question... What is the difference between the proportion valve and the metering valve? I looked on the Wilwood site and it seemed that most of their double bowl M/C were 8" long which would interfere with the diagonal tower brace. Right now I'm not wanting to alter the tower brace. SSBC has a double bowl, but if I read the text correctly it's for a "non-power disc brakes", so that's no help. I'll check with them on Tuesday to see the dimensions and whether they have a M/C for a power brake disc car.

Thanks,

Mitch
stubbie
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Re: Dual Bowl Master Cylinder...

Post by stubbie »

I'm by no means a brake expert but just passing on information that I learned a few years ago when looking into changing my 64 to dual master cylinder. I decided I would go with a dual 1970 Mustang master cylinder and a proportioning valve. I am also going to use the curved 66 shock top and modify the brace. I will be sticking with drum brakes all round. A proportioning valve regulates the brake pressure to the rear brakes. As weight is added to the front end when braking the valve reduses pressure to the rear to stop brake lock up. A metering valve adds pressure to the rear brakes first. When the rear pads make contact with the drums it then adds pressure to the front disks for even braking. An adjustable proportioning valve give you the option to adjust rear brake pressure to your own preference. I suggested the combination valve because it incorporates both metering and proportioning valves saving you the hassle of trying to set the adjustable rear brakes, which I believe can be difficult to get right. I know a 66 has a proportioning valve but I'm not sure if it also had a metering valve built in. If you want to read more look at this link. This is one of the places I spent time researching brake valves.
http://www.mbmbrakeboosters.com/index.p ... &Itemid=10
http://auto.howstuffworks.com/auto-part ... brake2.htm
Mitch I thought the flat top master cylinders would pass under the brace. Unfortunately you would probably still have to remove the brace to refill the fluid reservoir but without the brace mods. There is also a GMH master cylinder used by some of the guys here in Aust that must fit. It is shorter and more compact. Look at this link.
http://www.ebay.com.au/itm/Brake-Master ... 1644152202
gravelman
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Re: Dual Bowl Master Cylinder...

Post by gravelman »

Thanks Stubbie, I was aware of how the proportion valve worked, but unaware of what the metering valve did. Sounds like the metering valve is the way to go for disc/drum brakes...

http://ssbrakes.com/search.html?q=a0470-3

1" bore - 7-3/4" X 3-1/4" wide X 4" tall. From the center of the mounting bolts to the top of the reservoir lid it's 2-7/8" I'm going to make a wooden mock up to see if it will go under the tower brace. Too close to call for just measuring...

They also have another lid off of a Chrysler M/C (A0471-5) with straight milled grooves which I like better if the M/C fits our car. A bit pricey...

Mitch
mainstreetprod
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Re: Dual Bowl Master Cylinder...

Post by mainstreetprod »

Just spent weeks re building the brakes on my 66 and since I didn't care about originality I swapped in a dual master cylinder from the Bird house that fits the original booster. I replaced the proportioning valve with a generic hotrod valve. Calipers are original type and rear drums are stock. Today I took it out and tested it on a wet road and was very pleased with the performance- some wheels did lock but the car stopped straight and true. On a dry road it comes to a halt quickly with no screeching at all. No metering valve in my setup, just like from the factory (assuming the new master does not have one built in- some do).
66tanbird
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Re: Dual Bowl Master Cylinder...

Post by 66tanbird »

Mainstprod, could you tell me the name of the dual master cylinder that you purchased for your 1966 tbird. I would like to convert my 66 to a dual cylinder but BirdNest does not list any dual master cylinders for 1966. Thank you.
gravelman
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Re: Dual Bowl Master Cylinder...

Post by gravelman »

I'm looking at a 2014 Corvette dual reservoir master cylinder with it's booster. It's only 11" from front to back, whether the linkage can be adapted to the existing pedal works is another thing. And or if the M/C can be used with the factory booster. However I believe it's 1.250" M/C bore and whether that will make a hard pedal or not is up for discussion. I just don't want to hack up the tower brace to accommodate a dual reservoir M/C. I guess we all have our limits.

I'll report back if this works out...
Joe Johnston
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Re: Dual Bowl Master Cylinder...

Post by Joe Johnston »

I just don't want to hack up the tower brace to accommodate a dual reservoir M/C.
I have seen a conversion where the brace was just lifted about an inch by putting a spacer between it and the part that bolts to the shock tower. I do not know the type of master used though.
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