the dreaded trudle vac

I have rebuilt this miserable piece of junk too many times. Whats the cure ? is there a bolt in replacement for a GM power master cylinder for a 58 cad ?

part numbers, cost , where to purchase and any tips or problems replacing it ? Thanks

 

Rare Parts, Inc. Northern Calif.

Or just pirate one off a late fullsize GM, and make the bracket and push rod.

 

Thanks mike ! hey have you seen this thing ? its mounted up and down vertical !

 

I also had problems with the one I rebuilt and heard there were parts that needed to be welded up and turned back down to the correct size on them,dont know what parts the rebuilder was talking about but must be true since the one I rebuilt did not last long. A correct rebuild cost some money on them and I converted to manual brakes (53 olds) and was working on a plan to co back to power but ended up selling the car,I was planning on a small booster with a mastercylinder with a remote fill due to the booster mounting on the panel around the steering column and was actually under the column.

 

Treadle vac

 

There was a tech post on here a long time ago about adapting a more modern master/booster. My 58's sucked too.

 

Thanks T man and mike , it helps when you can spell . I did find this

http://www.jalopyjournal.com/forum/showthread.php?t=329070&highlight=the+best+55+caddy+build

But holy Cow ! there is nothing that will bolt in ?

Treadle vac , Dope !

 

Those T-vacs are junk, quit messing with it. That is my '55 Caddy build thread you've listed above...I wanted to keep the pedal on the floor instead of hanging off the firewall cuz I wanted my firewall clean. My system works well and here's something else, FWIW, we simply removed my brother's T-vac system in his '54 Cadillac and installed a new master cylinder and associated lines...he's been running it sans power for over 4 years now...never has a problem.

Another thing, we built TWO of those brake set-ups at the same time in anticipation of putting one in his '54...I do have pix of the set-up out of the car if you need them...and no, I know of nothing that will simply bolt in...!!!

R-

 

I would have to check on 58 Cadillacs, but I know that 54, and probably 55 Cads do not use treadlevacs, they use hydrovacs, which are a separate unit which is used to take the master cylinder output and amplify the pressure using vacuum, then using it's master cylinder, send the brake pressure to the wheel cylinders.

I have a treadlevac on both my 54 Lincoln and 58 Buick, and I have had no problems at all. I rebuilt the master cylinder on the Lincoln, and now the car stops very well. Another thing that might be noted is that the master cylinder used with treadlevac is a "displacement type" and does not have primary cups, only a secondary cup to keep fluid from coming out the back of the cylinder.

 

This is what it looks like in a '58. Sorry for the bad pic. It's all I have.

Mine needed to be rebuilt. Did the rest of the brakes, but the master was expensive to have rebuilt and I wasn't sure I wanted to change to a newer style.

 

Precision Rebuilders might be able to rebuild the unit. They can bore and sleeve many kinds of m/c and booster units to repair water and wear damage.
They're located in St. Clair MO. I've had them repair many hyd brake truck and equipment units.

 

If you have room on the firewall, it's not hard to just put a later hanging pedal and conventional master/booster on. The GM G-van pedal brackets are pretty compact and easily adapted; the 95-back hangs straight down, the 96-up is offset to the left about 7 inches, and you can change the actual pedal out if you want.

 

I drove a 55 Olds with one of those for 12 years and never messed with it.
Luckily it never went out, all I ever did was put fluid in it when I did brake work at the wheels.
It's unusual that I didn't "mess with it" since I usually go through the whole brake system on a car as soon as I get it home from purchase, but that one is just too weird.
I'd go to a lateer firewall mounted system rather than even open one up, and I'm an if it aint' broke don't fix it kind of guy.

 

Well mine were locked up from sitting so I reluctantly took the " Thing " apart . The master cylinder is no real trauma its the steal tube power assist thing . inside that thing is a piston that uses a leather type of o ring for a seal . Inside that piston is a floating control valve that is adjusted with shims . The floating control valve consists of two steal rings concentric with a sorta rubber diaphragm in between . That single part is 100 bucks and about five times that to have somebody rebuild it . There is a part to determine how many shims you will need , however no dimension to mic . Just a part number . if it sits too long it takes a set and the peddle will not return on its own . I took thing apart and cleaned and lubed it 4 times . I bunch if little fingers and springs ball bearing loose that act as check valves . It has got to go ! Maybe if I had sprung for a new floating control valve , just too cheap at the time now I don't want to mess with it any longer. I havent been able to drive because of this mess and one other prolblem in the way now as well