I looked for answers on other post but couldn't find what I was looking for.

I did a dual master conversion on a '64 Dart. I started with a brass sleeved master. I then put in a kit and replaced both of the brass orfaces and the valves behind them. I changed the metering block and used 2 adatpers to get the front lines into the new block. The block was provided by the owner of the car, so I can't say anything about that.

The pedal travels about 3" to "lock". On my dad's old Darts, the travel is about 1". All the shoes are slightly dragging, so that seems OK. I know someone else who had this problem, and he make the rod to the pedal longer, but all that does is effectively "pre-press" the pedal down by the added length, since the pedal stops on the brake light switch in the up position.

I would like to know if anyone else has had this problem, and if you have, what is the cause? I want to see if I can fix the cause, not the effect.

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Chuck Rivers, Webmaster

Re-bleed the system, using a pressure bleeder if you have access to one.

Few things that can be happening.... either your master cylinder not holding pressure, the wheel cylinders wearing out or leaking, or the shoes misadjusted. Seems like you got all these worked out, so the only other thing I can think of, as I said before, air in the system....

If everything is functional and your pedal is consistent, and you just want less pedal travel, you'd need a master cylinder with a bigger bore.

Does it have a good hard pedal? Pierre hit on the other question that came to my mind - what is the new m/c bore vs. the old one?

D/W

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If it ain't broke, fix it!

The pedal is not soft, and the bore is 1", same as the one I took out (unless I really missed something). It took a standard rebuild kit for a '67. I have blead the lines twice, I guess I could try that again. I don't have a pressure system.

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Chuck Rivers, Webmaster

A pressure bleeder can make all the difference. You can make one inexpensively out of a garden sprayer. Check out this webpage http://www.bmw-m.net/TechProc/bleeder.htm

I did something similar and it came out well. The only thing is you need some clamping system to keep the lid pressed tightly against the MC reservoir because those plastic reservoirs don't really have enough threads on the cap to hold pressure.

If your using an original style metal reservoir MC, then you need to get more creative.

If your going from 1" bore single pot to 1" bore dual pot in theory you will have less pedal travel, assuming your new MC is holding pressure.

Maybe the sleeve in your master cylinder made the bore smaller then stock?

Drum brakes all around, right? Does the dual m/c have residual pressure valves under the tube seats? I've had trouble with master cylinders missing those, sometimes you just get a bad m/c, too. I know you mentioned it was sleeved, but maybe there is a problem with the piston?

D/W

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If it ain't broke, fix it!

The bore is the same or else the kit wouldn't fit. I have used this re-sleever before and he does a good job. When I rebuilt the MC, I put new valves in behind new brass fittings. Looks like I may have to try a pressure bleed.

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Chuck Rivers, Webmaster

Chuck, Who is this resleever? I need a mc on my oldie Cushman Truckster resleeved.

The resleever is:

Sierra Specialty Automotive
3494 Chandler Road
Quincy, CA 95971
Phone: 800-4-brass-1
E-mail: sierrasa@psln.com

The E-mail address might be old.

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Chuck Rivers, Webmaster