Posted By: CokeBottleKid
Andy F modern MC adapter in A-body - 07/30/13 03:41 AM
So I have an A-body with factory manual brakes, I've done the conversion on other cars but always been power. What master cylinder do I need to get with the adapter? Looking for one with a 15/16 bore. Also is an adjustable rod necessary or not?
Posted By: RapidRobert
Re: Andy F modern MC adapter in A-body - 07/30/13 04:25 AM
An '89 Dakota has a 15/16" bore alum M/C but I do not know if it has the recess inside the rear piston recess "thimble" which is REQUIRED for a manual brake app. An alum M/C has either a thinner flange or the piston is closer to the flange (#2 iirc) which will want a shorter pushrod but the adapter moves the whole shebang forward which makes up for some (or all) of that distance. With the right (with the recess) M/C I would mock it up & go from there. There are several lengths of OE manual brake pushrods available
Posted By: MuuMuu101
Re: Andy F modern MC adapter in A-body - 07/30/13 04:51 AM
Dr Diff sells the MC and adapter as a whole (kit). I'm not sure if a manual pushrod works; however, I bought an adjustable one from him for myself. I'm in the process of doing this swap. Just need to repair my firewall.
Posted By: Burkenator
Re: Andy F modern MC adapter in A-body - 07/30/13 11:14 AM
My Dr. Diff kit worked great with my original manual pushrod. Did not even need to adjust to make my brake lights work correctly.
Posted By: DoctorDiff
Re: Andy F modern MC adapter in A-body - 07/30/13 03:59 PM
Unfortunately, no off-the-shelf, 15/16" bore aluminum master cylinder will fit a manual brake application.
As far as I know, I'm the only source for the master. I'm currently out, but the machine shop is working on another batch.
Posted By: Supercuda
Re: Andy F modern MC adapter in A-body - 07/30/13 05:23 PM
On this note, why not just run a 15/16" four bolt M/C? Other than the slight weight savings I don't see the benefit of the 2 bolt setup. I did check out Rock Auto to price a 4 bolt unit, about $30 for a new Raybestos Professional one.
Posted By: DoctorDiff
Re: Andy F modern MC adapter in A-body - 07/31/13 06:11 AM
As far as I know, my website lists A, B, and E body applications:
* 4 Hole for all A-Bodies and B/E-Bodies w/power brakes
* 4 Stud for B/E Bodies w/manual brakes
Posted By: DoctorDiff
Re: Andy F modern MC adapter in A-body - 08/01/13 07:20 AM
A 4 stud adapter does not fit manual brake equipped A-bodies because the studs are mounted in the firewall.