Brake Brain Fart

[RustyRatRod]

Yall help me out with a brain fart. Some of you may remember, I converted my 64 Valiant, Vixen to a tandem manual disc brake master cylinder a while back. It's the master cylinder where the front and rear reservoirs are the same size. If memory serves me correctly, I think it's the same drum to disc and the difference is the proportioning valve. Regardless of that part, I cannot remember which port is for the rear brakes. Is it the front port or the rear? Thank you drive through.

 

[Professor Fate]

Rear brakes- front reservoir.
Front brakes- rear reservoir.
Rear reservoir should be slightly bigger for discs, but a lot of people get away with using the drum master. Just keep a close eye on the fluid level.

 

[Dana67Dart]

but a lot of people get away with using the drum master

Remove the residual pressure valves behind the seats on a drum drum master


The first piston to move is the rear most attached to the pushrod. It pressurizes the front disk brakes.

Then pressure is built between the rear most piston and the front most piston to apply pressure to the rear brakes regardless if they are disk or drum.

The proportioning valve only limits the max pressure to the tears to prevent them from locking up prematurely

 

[RustyRatRod]

Rear brakes- front reservoir.
Front brakes- rear reservoir.
Rear reservoir should be slightly bigger for discs, but a lot of people get away with using the drum master. Just keep a close eye on the fluid level.

I bought it for a 67 A body with manual discs. So hopefully there is no residual valve. I'll look. Thanks! I thought that's how it was.

 

[Dana67Dart]

Ho about a photo of your master

The OEM master for KH front disk and rear drum is a typical rearmost reservoir 2x larger than the front most.

 

[RustyRatRod]

Ho about a photo of your master

The OEM master for KH front disk and rear drum is a typical rearmost reservoir 2x larger than the front most.


View attachment 1716513740

Yeah, so I've told yall for years how stupid I am. This just nails it down even further. I have the same type master cylinder in your picture. Disc drum. I'm a.....

 

[RustyRatRod]

But see, in my defense, I don't raise Vixen's hood often. But that's a good thing, right?

 

[Dana67Dart]

have the same type master cylinder in your picture. Disc drum

Big disk
Little drum

 

[RustyRatRod]

Big disk
Little drum

Yes. That's what I have now. I'll have 10 x 1.75 when I swap the 9" in it. My plan is to simply put an adjustable proportioning valve in the rear (front) port of the master cylinder.

 

[Desoto291hemi]

Yeah, so I've told yall for years how stupid I am. This just nails it down even further. I have the same type master cylinder in your picture. Disc drum. I'm a.....

View attachment 1716513743

Nope
Not at all. I think you are one of the smarter ones here
We all need a refresher course occasionally

A brain can only recall so much at a time
Lol

Tommy

 

[YY1]

Front reservoir is always for the rear brakes*.

However sometimes there is no larger reservoir.

 

[barbee6043]

Brain farts? I just light a match and it goes away!

 

[Mattax]

With the dual or tandem resevior the proportioning valve goes in the line to the rear drums after the safety switch.

 

[RustyRatRod]

With the dual or tandem resevior the proportioning valve goes in the line to the rear drums after the safety switch.

Lots of cats put it RIGHT THERE in the front port of the master cylinder, but I agree with you. That's how the MP manual says to do it. In fact, I seem to remember them saying to put the valve just under and in front of the driver's seat so the knob is on the inside and the driver can get right to it. That's how I did it on my 65 and it worked good.

 

[Mattax]

I suppose on a car without a brake warning light it really doesn't matter.
With a warning light, the last thing I'd want is something lighting up red when I'm braking hard enough for the prop valve to come into action.

 

[RustyRatRod]

I suppose on a car without a brake warning light it really doesn't matter.
With a warning light, the last thing I'd want is something lighting up red when I'm braking hard enough for the prop valve to come into action.

Yeah this has no light. lol

 

[Mattax]

Pointless with a single master. Dual master was supposedly safer but the times I've had a brake hose fail, my foot went to the floor and I said 'oh ****' before I saw a the dash light.