ok, i am sure there are threads on this but, what i would like to hear about is, how many of you have had single master cylinders blow out on you and what did you do if you were driving? i know after the '70's, everybody started all the fear ****ering about single mc's can blow out on you and cause accidents. or the front or rear wheel cylinders blow. what i would like to hear about is, how many of you have had it happen?
I've had that happen on an 80 International dump truck w/hydrovac single m/c abortion case, you pump the brakes, hit the parking brake, and steer around whatever you dont want to hit. Lucky for me I wasn't going fast just leaving the yard unloaded. All it takes is one leakey wheel cyl or rotten break line and the peddle goes to the floor. Put a duel m/c on anything you plan on driving faster than 5mph
I had a 55 1st series Chevy pickup back in 69-70. On the way from Gakveston TX to Mobile AL, I was p***ing through Pascagouls MS on Hwy 90. When a light turned red I braked and the pedal held for just a second then straight to the floor. Luckily there was light traffic I was first at the light and the beach was on the right so I wheeled right and stopped in the sand a couple hundred yards down the beach. Rear brake line from junction to RR wheel cylinder blew out from rust. Only time I ever experienced total brake failure.
Many years ago, I had a '57 Merc that the M/C failed while I was going about 70mph on the freeway. Started to slow down for a off-ramp, pedal went right to the floor. It is pretty scary. I still drive a lot of miles in cars w/single master cylinders, but I always try to leave a lot of room between me and the car ahead. Just pushing my luck, I guess. I've never had (or heard of anyone) having a complete brake failure with a dual M/C.
The dual is by far the safest but I have had one fail. I had bought a cheap one and wasn't going to put that "chinese ****" on my truck again. I ordered a raybestos from rock auto, the picture showed made in the USA but the part got here...made in china. FWIW the raybestos is still working good though
the only problem is that alot of dual system master cylinders have smaller bores. like 11/16. so you have to pump up the pedal if you have 4 wheel drums. so you need to make sure you buy a dual master with the SAME size piston as the single you had before.
Had a dual fail all the way also, luckly was just pulling into my brother driveway, bought a new one and no problems.
New Drum/Drum non-power dual cylinders are still available from your local auto parts store. They were used on drum/drum cars from about 68-74 after duals became fashionable/law and before everything changed to disc/drum and disc/disc. Your parts store can order them for you, doubtful they'd have one in stock, only take a day three usually. Example: 73 Dodge Dart non-power drum/drum. Bore sizes are listed in the Brake Parts Catalog at the store.
I had a complete brake failure in a 37 Ford coupe. I had just bought the car and was driving it home. When I went to slow down for a four way stop the pedal went to the floor. I grabbed the emergency brake and pulled it all the way out and got nothing. I downshifted into 2<SUP>nd</SUP> gear and was grinding on 1<SUP>st</SUP> as I rolled through the intersection. Fortunately I was the only car in the intersection. It was a terrible feeling. 37 Fords had cable operated mechanical brakes. Some previous owner had upgraded to 1940 juice brakes and did a ****py of running the lines. There was no rubber hose to allow for movement of the rear suspension. There was just a long steel line from the master cylinder to the rear axle. Metal fatigue on that line was what caused the problem. <O</O Nevertheless, I feel perfectly safe driving my older cars with a single MCs because I have made sure the entire brake system is in top shape.
6-volt, see now that's what i was wondering about. i know if the car is a work truck or something you didn't build, there is going to be trouble. if it is a car that we build, we are going to do it right. or at least i hope so. i built my henry j about 7 years ago and had a terrible time trying to get a mc to work on it. it has a '59 ford 9" drum rear and '54 chevy car front drum brakes. i went through several different mc's before i got the one in it now. the brakes were always hard as a rock but it wouldn't stop worth a dime. i did everything everybody said, longer pedal arm changed size of lines, moved mc from under floor to firewall, nothing worked until i got the mico mc. i remember back in the '70's about the mico power mc that everybody seem to be using back then. i thought, why not? it is a single mc, but it feels just like power brakes. it solved all my brake problems and i have not felt i will have any problem with it. the wheel cylinders may be a different story as they get older. thanks for the replies guys.
i've had one pop a line in my '60 elco and seen another in a lincoln down a hill into a crowded intersection...... not pretty. all my drivers have a dual master (elco is off the road now, but drove it many more years with the single).
I don't want a dual M/cyl on my hotrods but that is my decision. I understand others concerns. Remember the dual system M/cyl will still work marginally in the event of a broken wheel cyl., brake line or hose. That is the primary reason for the dual system. It's not the M/cyl failure. It's the failure of other brake components in the system and still have some partial brakes. I have had to replace 2 steel brake lines on my late model Ford P/U recently. The dual system allowed me to very carefully get home for repairs.
I've had failures on both types, but the difference is, when the single goes, you have NO brakes left. Maybe one or two pumps and you are done. When the dual fails, it's usually on one side or the other and it will start to sink and the brakes will be lousy, but you can get the car stopped.
I had a 67 chevy bus with a single master, kind of a party bus. Was driving it to a music festival when a real school bus coming the other way turned on its flashing lights, requiring me to stop. I hit the brakes and the pedal went to the floor. I about **** my pants. I wasn't going very fast and the bus was a good distance ahead. I down shifted a couple gears, grabbed the emergency brake, then shut off the engine. Luckily the school bus didn't have any kids crossing the road, and turned off its flashers just before I got to it. I was just about stopped then and was able to pull off the side of the road. The rear brake line between the rear wheels had rusted through at one of the hold down brackets. We replaced it on the side of the road. All of my rides have dual master cylinders and I will continue to build dual master systems on cars and trucks. The thought of hitting a kid still freaks me out. Red
Around '81, I had a '66 Mustang coupe. I was on the freeway and went to make an exit. Peddle went right to the floor. There were cars in front of me, but I noticed that I might be able to go around them. I'll never forget the looks from a family of four as I drifted past them. As I got on the feeder road, I used the emergency brake to come to a stop. Rear line had burst. Considering how easy it is to have a dual setup, not doing so is a study in stupidity.
In 2000 I had a 63 chevy with only 53ooo miles on it. I had added a 350/350. On the first date with my wife I thought it would be cool to pick her up in the 63. The brakes went out on the way to Fort Worth. I made it there and back using the e-brake. She never knew the difference. I was puckered......I only use the dual period.
Was pulling out of the Beloit Autorama when the brake pedal went to the floor at the first stop. Turns out the prior owner had cross threaded one of the brake line fittings and it finally let go. Topped off the master and planned my stops well in advance. I'll be looking for a dual master that will require a minimum of fab work to install. Got lucky that time. Don't wish to push my luck.
Dual master cylinder was government mandated for everything 1967 and newer. Not uncommon to see some cars as late as 1976 with four wheel drum brakes, with the disc front setups becoming the norm around 1971. Any master cylinder can be used with discs or drums. Bore size of the cylinder, piston stroke, reservoir capacity, and presence of residual valve would determine suitability for a particular caliper or wheel cylinder.
leaving Ft Huachuca about 25 yrs ago, the pedal went to the floor when the light turned red...used the parking brake to stop. NAPA was about 100 ft away, so I went there and bought a new brake hose and installed it. I only had one other failure after that, same deal with a worn out front hose. Strange thing is that in all the years of driving cars with dual master cylinders, I've never had a line go bad so I could see if it really worked. But you can test your dual setup, open a bleeder and see if you still have pedal. I'd bet that at least half of the cars that have been converted to duals, have them set up wrong so it doesn't work (pedal goes to floor). Something about the different stroke of single and dual cylinders, and how the dual needs to take up a lot of slack when one side goes out. try it
I've had the brakes fail over the years on several cars with dual master cylinder setups. The pedal goes damn near to the floor and the car slows so slowly it feels like dragging your feet on the pavement would work better. A well adjusted parking brake (remember when they were called emergency brakes) is probably more effective at actually stopping you (provided the brakes the parking brake cables are attached to aren't the source of the problem to begin with), and if you think either is going to bring you down from speed in reasonable fashion to keep you from hitting anything without a great deal of luck, you're dreaming.
I had a 57 Volkswagen oval window and the brakes failed on the way home form the beach. Just yanked on the emergency brake to stop first, then took off the c-clip that held the gears that made it click stop and drove it home using the e-brake like old-time cars. I drove it that way for a month until I had enough money to buy a new M/C. (it was when I was a teenager and broke, not now that i am old...and broke)
It seems a common occurence everyone is mentioning is brake line failures from either rusted lines or bad hoses. Although one of my projects this winter is to convert from my single M/C to a dual, I've driven several years with no issues - but the entire brake system was the first that was thing that was total redone when I got the car. I don't care if it doesn't start right, or run smooth, but I know it will always stop when needed. I just make sure anytime I have the car up on stands I check the lines and hoses, and at the first sign of any rust or cracking, it gets replaced. The cargo I normally carry, (kids & wife) is too damn precious to play with. Just my 2 cents !!!
Lost brakes a few times. One time a rear line burst -panic stop on the freeway - thank god for dual m/c - got it stopped but was scary. Another time driveshaft came apart (racing) the carnage included cuttin' the rear brake line. Again dual m/c - pedal went to floor, but still had pedal - car stopped ok as the front brakes were still working. Having to experience it one time is usually enough for you too get a good opinion about dual m/c
Ton's of gm and mustang 1" or 1.125" bores out there. non power brakes 1", power 1.125. almost across the board. Only newer, lighter cars started in with tiny bores. I can't think of a good reason to use a single, unless you are restoring a car that won't be driven like a hot rod. Duals give warning before they fail.
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