[GON_RACIN]

i just recieved my newer style big bore aluminum M/C from MagnumHP. It had slipped my mind until now, but the car i'm putting it on has 4 wheel drum brakes, and if i'm not mistaken this new M/C is designed for disc/drum and or disc/disc applications. Anyone know of any problems i might run into by using this M/C with a 4 wheel drum brake system ???

 

[383man]

You should use a Master cyl for drum brakes as most drum brake master cylinders have redisual check valves in them to actually hold a small amount of pressure in the brake lines. It works good with drum brakes as it's not enough pressure to overcome the return spring pressure. But if you use in on disc it will cause a brake drag as disc have no return springs they just release from the caliper seal relaxing. There are some drum brake systems that had wheel cyl cup exspanders in the cylinders and I believe some of them did not use the check valve. But I would want to use one made for drum only to be safe. Here is the one I used on my 63 as it was a single master cyl and I updated to this 67 setup. Ron

 

[GON_RACIN]

thanks 383man, i was afraid of that I'm getting rid of my suicide single M/C aswell, but the new M/C is already on the car full of fluid so returning it is not an option. I saw an add last night in the newest mopar muscle where a company is selling inline residual valves, i havent test driven the car yet but i may have to try one of those if the pedal is real spongy.

 

[GON_RACIN]

drove the car a bit this afternoon and the brake pedal feels a tad spongy, but its not unbearable. Its about the same as the single reservoir M/C that came off the car. There is maybe 1 or 1.5 inch of spongy travel before the pedal firms up when putting on the brakes. I reckon i'll just live with it for the time being, i really dont feel like tearing back into the brake system now that its back together.

 

[slow_motion]

street rodders use an inline residual valve---pick up a street rodder mag and start looking-----they need them because they usually put the master cylinder under the floor which makes it the lowest point in the system---not ideal to say the least.