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Looking for AL master cylinder for drum car
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Author:  sixsignet [ Sat Jun 13, 2015 12:13 pm ]
Post subject:  Looking for AL master cylinder for drum car
I have 10 in drums in front and 9 in drums in back.
Manual brakes.

I want to replace the perpetually rusty iron MC with an aluminum one.

Did Mopar ever sell a vehicle with an aluminum MC and four-wheel drums?

What aluminum master cylinder would work on my 63 Valiant?
Author:  Greg Ondayko [ Sat Jun 13, 2015 12:34 pm ]
Post subject:  Re: Looking for AL master cylinder for drum car
Quote:
I want to replace the perpetually rusty iron MC with an aluminum one.

Did Mopar ever sell a vehicle with an aluminum MC and four-wheel drums?

What aluminum master cylinder would work on my 63 Valiant?
You can also Just Rebuild and repaint your master cylinder.

No al Mc's from the factory for a Four drum car that I am aware of.


The 77-89 FJM Body Mc will work on your car - However I am not sure about fluid volume / brake bias. as it was designed for a Front disc / rear drum application with a proportioning valve.

This is the Part:
http://www.rockauto.com/catalog/moreinf ... 02&jpid=11

you will need this adapter plate to fit it to your car: or something like it.
http://www.manciniracing.com/mascylad1.html


Greg
Author:  SlantSixDan [ Sat Jun 13, 2015 1:31 pm ]
Post subject:  Re: Looking for AL master cylinder for drum car
Quote:
I have 10 in drums in front and 9 in drums in back.
Manual brakes. I want to replace the perpetually rusty iron MC with an aluminum one.
If it's rusty on the inside, you need to flush and fill the system. If it's rusty on the outside, you need to realize that's what they're supposed to look like. :-)
Quote:
Did Mopar ever sell a vehicle with an aluminum MC and four-wheel drums?
No.
Quote:
What aluminum master cylinder would work on my 63 Valiant?
None, directly. With an adaptor plate and a different pushrod, a 1"-bore disc/drum master would work mostly OK, though you'd want to install inline residual-pressure valves.
Author:  sixsignet [ Sat Jun 13, 2015 1:57 pm ]
Post subject: 
Valves, plural?
Doesn't the AL master cyl made for a disc-drum system have an internal residual valve for the rear drums?

Rusty on the outside.
Author:  Greg Ondayko [ Sat Jun 13, 2015 5:15 pm ]
Post subject: 
Many of the MC's came from the factory as Bare Cast Iron,,, Therefore that's how they get rusty and crusty on the outside.

Some did come painted Black.

I usually rebuild and Clean them, Wire wheel the crap out of the outside and then Clear it if you want the cast finish or Paint it black.


Any Brake fluid that seeps out of the cover / seal area will wash away the paint or clear tnd then it will be rusty again.. The engine heat can also expand the fluid and push it out the Cover vent and down the casting again too.

I prefer to keep the fluid 1/8" below the rim to allow for any expansion and minimize this effect .


Good Luck,

Greg
Author:  Dart270 [ Sun Jun 14, 2015 3:48 am ]
Post subject: 
IIRC, residual pressure valves were only needed for the really old style wheel cylinders with no internal spring. Every kit or WC I've seen since the 80s has a spring in it, so I believe the valves are not needed. This is just my recollection.

Lou
Author:  SlantSixDan [ Sun Jun 14, 2015 4:41 pm ]
Post subject: 
Quote:
Valves, plural?
Yes. One for the front drums and one for the rear drums.
Quote:
Doesn't the AL master cyl made for a disc-drum system have an internal residual valve for the rear drums?
No. Residual pressure valves were eliminated in '73, before aluminum master cylinders came along.
Quote:
Rusty on the outside.
Awful lot of work to overcome the normal appearance of a part that's working fine.
Author:  nm9stheham [ Sat Jun 27, 2015 9:31 am ]
Post subject: 
Just one thing to be aware of: I noticed that you list 10" front and 9" rear drums. Have the front end brakes been converted? (I see that the original is 9"/9" F/R.) Have you changed the wheel cylinders or shoe material on either end to try to maintain the original front-to-rear proportioning? If not, then the system proportioning is very likely out of kilter, with the fronts having more brake torque than originally designed.

On the drum/drum system of this car model, the F/R rear proportioning was set by the different F and R wheel cylinder diameters, but that is based on specific drum diameters and shoe widths. If you change a diameter on either end, it changes the braking torque on that end, and thus the F/R proportioning. With higher front brake torque, the fronts will be more likely to lock up, and in a wet road situation, you lose your steering traction when that happens.
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