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Useing a MC for Disc Brakes on a Front Drum Setup

khryslerkid

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What would be wrong in useing a dual mastercylinder for front disc brakes on a front drum system?
I am converting my single mc setup on the '62 to a dual mc. I eventually will change out the front drums to disc but not at the moment. I had the thought, why not use the required mc for the disc brakes for the front drum? The opposite wouldn't work because the reservoir for the front would be too small.
Thoughts?
 
Disc brakes needs more volume and more pressure and the drum MC probably won't do either but I've never tried using one on a disc system.....
 
When I changed out the single master,I used a cast iron one from a 67 Satelite for years before I installed SSBC discos.I installed a prop valve but ended up in full adjustment,,,,,,in other words I didn't need the prop valve:mad:



Your results May veiry:thumbsup:
 
A drum master has a residual valve in it to keep the pads from dragging. Probably not that great an idea to use a disc master on drums without said residual valve.

Might want to see if anyone has a lightly-used drum master in the Wanted forum; see if you can get one cheap that will get you by until your conversion.

-Kurt
 
A drum master has a residual valve in it to keep the pads from dragging. Probably not that great an idea to use a disc master on drums without said residual valve.

Might want to see if anyone has a lightly-used drum master in the Wanted forum; see if you can get one cheap that will get you by until your conversion.

-Kurt
Actually, the residual valve on a drum MC is to help keep air from entering the system. The springs on the shoes keep them from dragging but as they compress the wheel cylinder pistons back to rest position, a bit of air can enter the lines on systems without the residual valve . The 'square' ring on the piston of a disc brake caliper is what helps pull the piston back a hair to keep the disc pads from dragging but as they age, they don't always work so well but generally, air won't enter the caliper. I would suppose that a drum MC would work so long as the residual valve is pulled out of the rear section of the MC and the MC puts up enough pressure to keep the driver from having to stand on the pedal to make the discs work like they are supposed to. I do remember another member having that problem and then when he installed a gauge, he found that the PSI was way low. You can find what the PSI ranges are for both systems by doing a search on the net.
 
Might want to see if anyone has a lightly-used drum master in the Wanted forum; see if you can get one cheap that will get you by until your conversion.
The money isn't a problem. It's the thought of changing out the mc twice. That's not really a big thing either. I plan on using the silicone fluid for the safty if any gets spilled and of course the cooling and corrosion factor.

The reservoirs on a disc brake mc would be sufficient for a all drum system. I'm just not sure if the piston would be right for the power and timing.

Interesting point about the residual valve.

If I don't hear a response from someone who has tried this, I'll have no problem useing a drum dual mc first, then change it out later for the disc.

Thanks to all for helping me kick this idea around!
 
I havn't done my homework yet,but I want to replace the master with a newer one,like out of a dakota or diplomat that has an aluminum body and plastic reservoirs.
Start chipping away at this overweight brick!
 
"HEMI-ITIS, post: 910521375, member: 895"]I havn't done my homework yet,but I want to replace the master with a newer one,like out of a dakota or diplomat that has an aluminum body and plastic reservoirs.
Start chipping away at this overweight brick!

well maybe....
"stop carrying all those Delmonico steaks in the trunk"..
 
Pops,I prefer to chase them SKIRT steaks!

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