Heh..!!! Will This Work..??? Can I do This..??

[Viet Nam Vett]

Can I use a Dual 67 Corvette Master Cyl..Non Power Assist on my 65 Cp??

Will it bolt up and work with my brake Pedal linkage? I want to convert the car for safer operation. I understand that I will have to add the lines and the proportioning valve and the other related gack..

Thanks..

 

[6T5RUSH]

Viet Nam Vett,

Absolutely. That is exactly what I did for my '65 vert. After replacing the front bronze block and buying a length of tubing to connect the front master cylinder orifice (it is a larger size than the rear) to the new front block, I just carefully bent up the existing long line to the rear orifice of the new master cylinder. Great piece of mind!!! If I remember correctly the master cylinder ran me less than $80.00.

Go for it!!

Jim (6T5RUSH)

 

[markiemyster]

DIDO on that Mark.
That was one of the first mods I did when I got my 65 a few years ago.
I bought a conversion kit from ZIP.
Instalation was about 2-3 hours as I remember.

Good luck

Mark

 

[67HEAVEN]

I understand that I will have to add the lines and the proportioning valve and the other related gack..

Gack! I like that word.

 

[Viet Nam Vett]

DIDO on that Mark.
That was one of the first mods I did when I got my 65 a few years ago.
I bought a conversion kit from ZIP.
Instalation was about 2-3 hours as I remember.

Good luck

Mark

Thanks guys for the reply... Did you use or install the proportioning Valve in the system or leave it out?

 

[Viet Nam Vett]

Gack! I like that word.

Yeah..Gack...It comes from the "Jonny Fever" era... Also the early eighties ..as when you asked some one if they had any "Gack" Or "Snow" Or ....Have you seen the "Enemy" around??

Also used to describe the crud or oily stuf in your crankcase or the hard rocky stuff found in your nose when arrising in the morning. Sometimes found in your eyes....when they won't open and require two fingers to pop the lids up.

Gack...a Fun word.....Gack can be good..or Gack can be bad. ...Gack.......

 

[6T5RUSH]

Viet Nam Vett,

No "proportioning" valve. I've got manual brakes. It's not needed. I believe because the front portion of the master has a larger diameter line then the rear, it was plumbed to provide more pressure to the front vs. the rear. Therefore, in my mind, already "proportioned. I'm sure the gurus on brakes will chime in here and provide you with the technical side. With that new dual master, my '5 stops on a dime, straight; but, more importantly, should I ever have a leak in one of the wheels, I'll always have the fronts or the rears to brake with!

Jim

 

[67HEAVEN]

Only the J-56 HD brakes got a porportioning valve in '67 (267 factory built).

 

[Viet Nam Vett]

Only the J-56 HD brakes got a porportioning valve in '67 (267 factory built).

Ok.....So are you running the valve below the MC with the idiot light and fluid stopper leaker pin...:L or are your do your lines go directly into the MC??

 

[67HEAVEN]

Ok.....So are you running the valve below the MC with the idiot light and fluid stopper leaker pin...:L or are your do your lines go directly into the MC??

Yep.

 

[Viet Nam Vett]

Yep.

Ok:BOW

 

[JohnZ]

Viet Nam Vett,

No "proportioning" valve. I've got manual brakes. It's not needed. I believe because the front portion of the master has a larger diameter line then the rear, it was plumbed to provide more pressure to the front vs. the rear. Therefore, in my mind, already "proportioned. I'm sure the gurus on brakes will chime in here and provide you with the technical side. With that new dual master, my '5 stops on a dime, straight; but, more importantly, should I ever have a leak in one of the wheels, I'll always have the fronts or the rears to brake with!

Jim

Jim, the master cylinder bore is one diameter for its full length for both pistons; the proportioning is designed into the system via different caliper piston bore diameters between the front and the rear.

 

[6T5RUSH]

JohnZ,

Thanks for setting me straight. So, is the different diameter brake line for the front vs. the rear part of this "proportioning" equation to, in effect, distribute "more pressure" via fluid to the fronts? Seems like that's the case for all those who did this conversion without the valve.

As always, thanks for your expertise JohnZ!

Jim

 

[JohnZ]

Jim, pressure in a closed hydraulic system is the same everywhere in the system, regardless of line size (assuming there are no pressure-regulating or proportioning valves in parts of the system); all line size affects is the amount of fluid required to fill the system. The only thing that affects the pressure of the pads against the rotors is the diameter of the pistons in the caliper, which is why '65-'82 Corvettes have smaller-diameter pistons in the rear calipers than in the front; that's "designed-in" hydraulic proportioning.

 

[6T5RUSH]

JohnZ,

I "see the light"! Thanks for clarifying this!

Always learnin'!!

Jim

 

[Ol Blue]

John or anyone...

Is there any reason that the 67 dual master cylinder would NOT work on a 63 or 64 drum brake car? Years ago I was lucky in that with each car the brake line bursting happened in the driveway after I had bled the brakes and was checking the pedal.
For any of you that still have the original lines, you might want to check the long line that goes from front to rear along the drivers side frame. Mine rusted through right where the clip was holding it to the frame. Probably because of years of salt and sand collecting there.
Thanks
Ol Blue
http://www.knology.net/~corvettes/63vett.jpg

 

[JohnZ]

Drum brake master cylinders have RPV's (Residual Pressure Valves) in the outlet ports, which maintain about 10 psi in the brake system; that overcomes some of the retraction spring force and keeps the shoes out close to the drums to minimize pedal travel when you step on the brakes. Disc brake systems don't use RPV's, as it would fry the pads and rotors.

A rebuilder MIGHT be able to install RPV's in a '67 master cylinder; if not, use a '67-'69 Camaro drum brake master cylinder - it's a dual master cylinder, designed for drum brakes, and has RPV's in it.

 

[Ol Blue]

Thanks John

I "think" i have a 68 Camaro dual master cylinder that I took off of a junked car back when my gas line burst, but I think it had disk brakes on it.
Ol Blue