64 Dual MC conversion questions.

[jsgun]

I'm replacing my brake lines, and converting my single master cylinder to a dual chamber. I bought a 67 Buick drum/drum MC, but the plunger is different. The 67 takes a short plunger, and my 64 booster has a very long plunger shaft. Easily 3" hanging out of the booster. Did I get the wrong MC? Do I cut this rod, and if so how much? Search function helped some, but i'm still not clear on it.

 

Anyone know what the fitting sizes for the MC lines are? They're considerably larger than the 64's. Any junction blocks I should use? Maybe Impala? My original is kinda not usable, the rear line fitting is seized in it. Might as well replace it with something that works easily with the dual MC.

[KongaMan]

There are two MCs: Delco and Bendix.  One takes the short plunger, the other the long.  Sounds like you got the wrong one.  

 

IIRC, Bendix has the deep hole and takes the long shaft.  It also has a screw-on cover while the Delco is held on with a wire clip.

 

I think the fittings are 9/16-18 and 1/2-20.

[telriv]

I have a good used distribution block IF you destroy yours upon removal of the rear line.  To plump your new M/C after you remove the rear line put a plug where you removed the line.  Remove the line from the original master. Fabricate the new line & connect it to the block where the original line went. Now run the rear line of the M/C to the rear line & connect them with a connector.  Done!!!!  Very little brake line fab required. Don't forget to give the new lines coming out of the master a couple curls to help keep the flexing lines from being over stressed & eventually breaking.

 

Tom T.

[jsgun]

I got the Delco MC, so that adds up. I'll start looking for a Bendix.

 

I got up close and personal with the frontend, while replacing that brake line at the crossmember. Looks like one of the PO's rebuilt the front suspension and brakes. Sitting for a decade dry rotted the rubber hoses a little, but the rest looks great. Rearend bushing need replaced, but i'm grateful about the front.

 

Tom - I may take you up on the block, but i'm hoping I can get the fitting out of mine with some persuasion.

[KongaMan]

Don't use too much persuasion; you don't want to bung up the fitting.  

 

If that's going to be a problem, you could run the rear line through the junction block (plug the other holes) and fab a new line with a tee for the front.  That's not the way folks normally do this, but it's easier than reflaring, patching, or replacing the main line to the rears.