Technical Disc brake with fruit jar master cylinder

I put disc brakes on the front of my 1960 Merc Monterey convertible,, still using the stock drums in back. Can I use the original single resivoure master cylinder, non power?

 

I would search out an appropriate dual master cylinder.

 

My Model A coupe has four wheel disc brakes with the fruit jar M/C and the T-bird Midland power brake booster. It was on the car when I bought it and worked pretty well until recently. Now that it quit working, I won’t be repairing it, I’ll update to a dual system, non power.
Everything else aside, hydraulic pressure is hydraulic pressure, as long as the brakes are adjusted properly it should “work”. But it’s far from being optimal as far as performance and safety.
I would update to a disc/drum dual master cylinder.

 

What they said about upgrading it but, I had a disc drum set up with the GM fruit jar for over 10 years with no problems the only reason I switched was to put Power brakes on it. 1964 El Camino

 

I am going to break a rule here and post on this subject.
This is not an answer and without a doubt no one needs to follow these practices. So just examples of what I have seen done with good success. Take it or leave it.

I used to tune a Stude, a Lowey coupe. It ran GM metrics in the front and Ford drums on the rear (smaller drums). For at least 7 years that I know of it ran the stock single master under the floor board, no power single reservoir. This particular car got driven all over the United States, not trailered.

Now this is a little OT but good for an idea for the masses. In '69 I was screwing an A coupe together with a buddy. We decided that hanging peddles were the chit, and he really wanted a dual reservoir. In a fit of intelligence I decided to ask one of the old guys what would work best. he got under his bench and handed me two jelly jars. I guess I looked confused and he laughed and scrawled out two attached by a balance bar. That was what the A bone got. One fed the front and the other fed the rear.

 

I worked on a NASCAR team back in the 80's and that's all we used , we did put a taller filler cap to increase volume

 

yes it will work, keep an eye on fluid level as the brakes wear.

 

“Can I use” or will it work? Yes it will work.

 

yes you can use it, but you might want to remove the residual pressure valve, from inside the master cylinder.

 

Studebaker Avanti in '63 used a single master cylinder with disc on the front and drums on the rear.

Just because it's been done that way in the past, even though it worked well, doesn't mean there isn't a better way to do it today. It would be very easy to upgrade your '60 to a dual master with a proportioning valve to make the overall job conform to more up to date safety standards.

 

I've built many hot rods with disc brakes on the front & drum in the rear with a single
"fruit jar" master cylinder. Having the correct master cylinder bore dia. is important.
I also remove the internal residual valve.
These cars have traveled thousands of miles.
Example, in the 1990's Thom Taylor & I built a '36 Ford sedan delivery project car for Rod & Custom magazine.
Super Bell supplied the disc brake kit, and they asked me if I would experiment with a single "fruit jar" master cylinder on the project. I let them know I had been building them that way for years!
Thom & I drove that '36 to Springfeld Mo. to the "Americruise" & Thom drove it for many years safter!

 

I had a basket of parts that came with a car, and in it was a wilwood setup with two single cylinders for brakes, and an additional cylinder for the clutch. Looked good. I put it on another project car and sold it, so no experience with it after that.

 

I know a guy locally who has an early Falcon with KH front disk brakes and drums in the rear, single master cylinder. I've driven it and it stops ok, but I don't remember it trying to put me through the windshield.

Devin

 

My 66 Studebaker had non power disc brakes . Single piston front calipers, and 7/8 rear wheel cylinders. Looked like the ford master cylinder.

 

I will probably put the dual piston master cylinder eit, makes me feel safer

 

Just a nudge reminder, guys. Brake fluid is a maintenance item. It's not how many miles you drove or how many times you pushed the pedal. It's how long it sat in the system soaking up water molecules. Even a partial can sitting on the shelf is liable to absorb water over time. Don't throw it away but use it within its "freshest if used by date".

 

Got one in my coupe. I believe I removed the check valve in the master. Works great…..but it’s a little car.

 

Do yourself a favor, get a manual disc drum / master cylinder for a 1969 Mustang. It is a bolt in. Run a new line from the larger fluid port down to the lower "T" that splits the front and rear lines into the port that would normally feed the rear line and run a line from the smaller fluid port to the rear line through an adjustable proportioning valve. Adjust the valve so that the rear brakes don't lock up before the fronts. An extra couple hundred at most and you got your bases covered. I did this to my 64 Marauder. Had a single bowl MC many years ago, blew a wheel cylinder and then the stop sign and almost got T boned. Never again. Larry

 

like this?

 

if you convert it to a double master cylinder, do yourself a favor and make sure that it will do what you think it will. After it's installed, open a bleeder on the front, and see if it still has brake pedal, or if it goes to the floor. If it still has pedal, try it again opening only a rear bleeder.

This is a useful test, because the pedals on old cars are not set up to push the piston as far as cars that came with a dual cylinder, and if it bottoms out before you get brake action, then you've wasted all your effort adding the dual cylinder.

 

That one is a dual drum/ drum. The disc /drum one has a larger reservoir for the front disc. And as Jim mentioned in some cases I have had to extend or relocate the push rod on some applications.

 

I use the 1979 Ford Fairmont none boosted master, works great.

 

If you install a duel chamber master cylinder, you must also use all the tubing and brass proportioning valve that is included on the original doner car. With out it, the pedal will just go to the floor when bled just like any other master cylinder. There is no safety factor without that tubing and valve.

 

Mopar used the single pot master cylinder in 66 on their A bodies. They used a master cylinder extension-Rare! Here is a picture from a 1966 Barracuda

 

Sorry about the double pictures. This is a disc brake car.

 

If you have ever had a wheel cylinder fail with a fruit jar master cylinder and you were rolling down hill against the flow of traffic at school pick up with no brakes, then you would not even consider not using a dual master cylinder. I have experienced it. Was very lucky once. Don't ever want to try it again!

 

Some people like to gamble, with life itself.

 

It used to be sufficient to have a manual brake (parking/emergency brake) to deal with situations like that. For some of us, it still is.

Almost everyone killed on US highways today has a dual braking system in their car, plus a manual brake. Doesn't seem to prevent catastrophe, in the eternal gamble of driving. Strange.

 

Also make sure that your emergency brake is in working order. And if your ride doesn't have one, it's time to install one.

 

Everyone does every day , its a matter of risk ,everything you choose carries a degree of risk !

 

Is a dual master cylinder better than a single master in a catastrophic failure ? Yes it is . At the very least it does give you “ some” brakes . I think there is a false sense of security that a duel master if one side fails you still have 50% of your brakes . You don’t , maybe 15-20 braking power left . Not great , but still better than nothing .

a proper working Parking brake or “ emergency brake “ is far better in an emergency situation .
I’ve owned many winter beaters over the years and have had brake lines fail etc , and the parking brake has always saved my bacon .


Not to veer this conversation off course but more importantly the a duel or single master disc or drum set up . But prober brake system maintenance is the single most important thing you can do. Flush your fluid every couple years , inspect lines , hoses and tube , etc etc etc .

I prefer a non power duel master system mounted on the fire wall as you get the extra safety of a dual system , being non powered the fire wall stays non cluttered . But the entire system needs to work together and have fail safes and be maintained correctly .


Ok off my soap box and back to my day .