Single to Dual Res Master Cylinder Conversion

[LostMy65]

Please don't close this thread, and please add it to the FAQs. Thanks.

[BabyBlue64]

Last week I saw my original single Master cylinder is leaking, so I want to do this upgrade also. I found this thread but the pictures in the original write up are gone

[Captainfab]

If you are staying with manual drum/drum brakes it is quite simple. All you need is a '67-'70 master cylinder. The front port is the front brakes and the rear port is the rear brakes. Then you will need to add a second line on the back of the suspension crossmember to feed brake line that goes to the rear.

Originally Posted by BabyBlue64

Last week I saw my original single Master cylinder is leaking, so I want to do this upgrade also. I found this thread but the pictures in the original write up are gone

[jocko]

BabyBlue, I’m still seeing the pictures, they were attached thru this site, not a third party host, so should be visible. Can you let me know which posts you are not seeing the pictures on?

[BabyBlue64]

Hi Jocko, I mean the pictures of Chief's original write up, where you refer to in post #12.

[D'Monsta]

My single was leaking so I decided to do this conversion today.. all bled, feels like good pedal, but the brakes barely grab and just kind of coast to a stop no matter how much leg I put into it.. Is there a special way to bleed a dual master or is the 'furthest away, then next furthest, etc.. still the way to do these? I read somewhere else that the front and back from each side should be bled at the same time.. Gotta get this done.. My brakes are worse now than with the single MC

[jayoldschool]

Did you bench bleed the master? Bleed order: RR LR RF LF. Sounds like you have air. Maybe open up both rears and gravity bleed it for a bit, keep topping master. Then do fronts. Then, two person pressure bleed in order.

[D'Monsta]

Yes, Bench bled the master.. I will redo the bleeding sequence tomorrow.. Probably time for brake shoes too but I want to get the hydraulics in order first..
Thanks..

[Captainfab]

The correct brake bleeding order is LR, RR, RF, LF.

[D'Monsta]

Thanks Gents.. Got it done.. Nice high. firm pedal.. Will lock up with a firm push now.. I used 3 couplings, one plug, one length of new tubing and some pre-made supply tubes from NAPA.. Nothing fancy but it works great. Peace of mind.. Fixed the E-brake a while back too..

[G8rN@te61]

I found this thread as I am in the process of looking at changing out my master cylinder and doing some all around brake work. Question I have is when changing out the master cylinder, how do you handle the clutch that operates off it too? I have a '61 btw.

[LostMy65]

Originally Posted by G8rN@te61

I found this thread as I am in the process of looking at changing out my master cylinder and doing some all around brake work. Question I have is when changing out the master cylinder, how do you handle the clutch that operates off it too? I have a '61 btw.

.
These threads might help:
.
http://67-72chevytrucks.com/vboard/s...d.php?t=362375.
.
http://www.67-72chevytrucks.com/vboa...d.php?t=339335
.
http://67-72chevytrucks.com/vboard/s...d.php?t=300087
.
.