Finally a brake upgrade

[BattlestarGalactic]

After 20 yrs of single master cylinder and drum brakes, I am upgrading the 2 dr to some better stopping power.

With taking the Tbird brakes off the wagon this past winter for some Wilwood updates, I'm reissuing the Tbird brakes to the blower car.  Something that is was much needed and I got constant grief over when people saw that little single pot master cylinder on that car.   

I cleaned up and painted the spindles, got some new Russell DOT braided lines, a new master cylinder and proportioning valve.   I got the m/c painted and mounted Sunday, along with the brakes.  I picked up some new line and appropriate fittings yesterday.  I have the two lines to the p/v fitted.  Now just need to get the rear brakes attached and the brake light switch.

I was hoping to get an adapter to convert 3/8"-24 flare to 1/8" pipe, but they don't go that way.  Only 1/8" pipe to 3/8" flare.  Ugh.  I'm going to have to add a 1/8" npt Tee and then get adapters for 3/8" flare.  Little more bulky looking then I wanted, but I can hide it down behind the steering box and still plug the pressure switch in using the original wiring.  I could go mechanical switch under the dash?  The jury is still out on that.  I'd like to just use the factory wiring, though it is not that important.

Here is a few pics, need to get more tonight:

Brakes bolted on:


New m/c:


The old single pot still going strong:

[cjshaker]

Funny, I drove them for years on my Falcons and Comets, and a dozen other old cars, and never gave it a second thought, but ever since the one let go in my '65 Galaxie a few years ago, they make me nervous. Especially since just a couple days before I was following a friend in his freshly restored '68 Mustang fastback. If it had let go then....   I finally changed it out last year before driving it to Atlanta for Drag Week. Now I cringe every time I see single pot cylinders.

[Stangman]

I also thought the single master was fine, until my 64 Lemans let go. Not a good feeling. Drove up on a sand median to stop, right before a busy intersection.

[BattlestarGalactic]

Back like 20+ yrs back, before the blower motor in 2000, I had driven the car to a buddies place one evening.  No problem.  I went to drive the car to work the next day and the pedal fell to the floor backing out the driveway.  Huh?   I unscrew the lid and it's DRY.  Bone dry.  How did it work fine the night before?  I installed the present single pot and it's been fine since then.  I put all new wheel cylinders on it before I even started driving the car.  Still don't know where all the brake fluid had gone?

[RJP]

Back like 20+ yrs back, before the blower motor in 2000, I had driven the car to a buddies place one evening.  No problem.  I went to drive the car to work the next day and the pedal fell to the floor backing out the driveway.  Huh?   I unscrew the lid and it's DRY.  Bone dry.  How did it work fine the night before?  I installed the present single pot and it's been fine since then.  I put all new wheel cylinders on it before I even started driving the car.  Still don't know where all the brake fluid had gone?

I learned the hard was about "new" wheel cylinders. Brand new out of the box, installed with no problems...worked just fine for a few weeks. Sitting in line to get into a car show the brake pedal goes to the floor. WTF? Released the pedal and reapplied and braking was back to normal. No more problem until later and the pedal goes to the floor once again. Checked for leakage at all 4 corners and no brake fluid visible. OK, what now? Seeing that I was 300 miles from home I chanced it and drove home without any further problems. Got home and into it and found that one of my brand new wheel cylinders had a rubber piston seal installed backwards. It sealed, most of the time but there was no radial seal against the wall of the cylinder. I now inspect all wheel cylinders before installing.

[BattlestarGalactic]

Late friday wheel cylinder assembly??

Just like I open every oil filter box before purchasing.  Buy one filter without any threads in it and you will ALWAYS open the box and inspect it before buying it!!

[EricDS]

I just changed the single pot to a dual circuit MC in my 64 Monterey last weekend.  All new brake lines front to back too. 

It might just be 100% in my head but the car just feels like it stops so much better.  Much more confidence inspiring driving around town.

There is a brass tee I used that is female 3/8-24 flare on both ends and female 1/8" NPT in the center for the brake switch.  I can probably find the part number if thats what you are looking for.

[BattlestarGalactic]

I'm sure these disc's will make a world of difference in stopping.  They worked well at 120 mph in the wagon!!!

Thanks for the offer on the Tee, I have one coming this afternoon from local parts store(old school store with real countermen).

[Rory428]

Funny how everybody thinks a dual chamber master cylinder means that you will still have brakes if a line or hose breaks. At work we have had numerous trucks come in with rusted out brake lines, and in every case, the brake pedal sinks all the way to the floor. Has anybody not wondered why when bleeding the brakes on a dual master cylinder car, after replacing wheel cylinders, lines etc, when pumping the pedal, and after building pressure, once a bleeder is open, the pedal will go all the way to the floor? Personally, I have always considered the dual chamber master cylinder theory pretty much the same as "self adjusting" drum brakes. In theory it makes sense, and they SHOULD work as described, but in real life, not so much. Pretty common to have cars and trucks at work that have excessive parking brake travel, and a low pedal, nothing that adjusting the rear brake 15 or 20 clicks won`t cure, even though they self adjusters are supposed to eliminate that need.

[RustyCrankshaft]

Funny how everybody thinks a dual chamber master cylinder means that you will still have brakes if a line or hose breaks. At work we have had numerous trucks come in with rusted out brake lines, and in every case, the brake pedal sinks all the way to the floor. Has anybody not wondered why when bleeding the brakes on a dual master cylinder car, after replacing wheel cylinders, lines etc, when pumping the pedal, and after building pressure, once a bleeder is open, the pedal will go all the way to the floor? Personally, I have always considered the dual chamber master cylinder theory pretty much the same as "self adjusting" drum brakes. In theory it makes sense, and they SHOULD work as described, but in real life, not so much. Pretty common to have cars and trucks at work that have excessive parking brake travel, and a low pedal, nothing that adjusting the rear brake 15 or 20 clicks won`t cure, even though they self adjusters are supposed to eliminate that need.

I think the dual chamber masters work as described, but for the master to hold pressure when a failure happens you need the combo/safety shuttle valve to close off one side and those are what never work. Some are built into the master, some are on the frame rail and I've never seen any that work correctly. They're "supposed" to be pressure and velocity sensitive so that bleeding the brakes won't set them off but a sudden loss of brake pressure will.  Best bet is to pop the master lid every couple years and make sure your parking brake is adjusted!

[cjshaker]

Dual pot master cylinders do work. Will the pedal go down if a line breaks? Yes, but you'll still have some brake when you get to the bottom (at least in my experience), and some brake action is better than no brakes!

And self adjusters work also. When you put new brake shoes on, do you have to run the adjusters in? Yes, every time. That means they're working. Having to adjust the emergency brake is due to the cable stretching over time.

I don't know, maybe Canada is different? 

[BattlestarGalactic]

Agree, those shuttle valves typically freeze up and don't work.  When new, I suppose they are fine.  When I lost a line a few years back in my '89 F150, yes the pedal was nill, but at the bottom it would stop the truck(though not abruptly).

My '95 F150, I typically pump the e brake randomly to help adjust the rear brakes.  The brake pedal will be noticeably lower, so I pump the ebrake and it will stiffen the brakes up.

I was always told you need to back up and hit the brakes to help adjust them?  That rocking motion pulled on the cable and would ratchet the adjuster.  Another old story always told back when, but not needed so much in todays world with 4 wh disc brakes.

Here is what is done so far:

I have the two lines to the proportioning valve.   It's unfortunate that I had to twist the lines due to master cylinder orientation.   I prebent some coat hanger to help get it laid out so I could bent them some what evenly.  I'm not OCD, but I do try to make things look "right" to a point.  The hardest part is putting a tight 90* bend right after a fitting.  Never found a way to do it.



I got my pressure switch mounted, run in the rear brake line.


I reused the original block in the front to run the front brakes, I plugged the rear line port and trying to reform the line to come up the firewall to attach to pressure switch Tee.  I  used the existing front line to connect the block and the proportioning valve.

I spent some time trying to figure the m/c lines.  If I wanted them just straight down, I would need to reverse the PV, but that would make me redo the front brake line to come up the firewall and the rear would come out the front.  Didn't seem easier, so I did the twist version as shown.

I'm likely going to have to drop the drivers inner fender out to get the rear brake line attached.  Just no room to get in there.  The existing line is plenty long enough to reach the pressure switch, just can't get my hand in there to bend it.

The nice thing was the local parts store had all the proper line ends to attach everything WITHOUT having to use adapters!!!!

[cjshaker]

Reversing is what works the adjuster. When the shoes are cocked backwards (in reverse), it pulls on the cable and pulls the adjuster lever above the adjuster wheel. When somebody has an issue, it's almost always that people don't take the time to clean up the adjuster pin, where it needs to spin freely. It's also a bad idea to use a heavy grease on the pin, like wheel bearing grease. A light coat of oil works best.

Some people remove the adjuster cables (seen that lots of times), rather than replace them or fix the issue with a stuck adjuster. I guarantee you that it makes a big difference in braking, as the shoes wear over time. It'd be like losing 20-30% of your braking ability, or whatever they say the back brakes amount to. On a drag car, with skinny front tires, that can be huge!

[TomP]

I have lost the brakes completely in three different cars with dual master cylinders. In two of those it was an "upgrade" from a single master (65 Falcon and a 53 F350) and the other was the factory dual master on my 67 Ranchero.
  The truck lost a caliper when the huge forged 79 F350 spindle spread and the caliper flew off into the canyon. Just that missing hose made the pedal go to the floor and pumping didn't stop it. The Falcon burst a rear wheel cylinder and I went sailing through a just changing to red light in front of traffic. Ranchero was also a rear cylinder and it went through an intersection and bumped a Nova.

 I leave single masters on all my cars now. I am using 4 wheel discs with a 65 Mustang large "jam jar" master on my 62.

[BattlestarGalactic]

Tom, like Rusty mentioned, if the shuttle does not move then it won't shut the broken line off.  That valve should move with the sudden change in pressure.  My guess is since they don't get "used" in 20 sum years, they get gunked up.  Thus rendering them useless.