Anybody switched to a dual reservoir master cylinder?

After losing my brakes last Friday, I'm planning on going over the entire system, and upgrading to a dual reservoir master cylinder while I'm at it. My hunch is that my current master is leaking into the booster, however I haven't torn it apart just yet.

My plan is to go with a master cylinder from a '67 Wildcat for a drum/drum Delco booster. None of my local parts places can locate the proper booster at the moment, so I am going to re-use my current booster as it still works like a champ.

I believe I already have all the necessary adapters. I've got adapter lines to go from the old style 7/16" fittings to the 1/2" & 9/16" fittings of the new master. I have a union to connect the factory rear brake line to the new adapter line. I also have an adapter to connect the factory 1/8" NPT brake pressure switch to the now un-used port (from the rear brake line) in the factory distribution block.

I think I've got all my bases covered. And I believe I should be able to re-use my current booster, although that may not be the wisest decision. The only thing I think I might need from reading a few threads on the subject is an o-ring to seal the master to the booster. Does anybody off hand know the size, or have a part number? Is there anything else I'm over looking? Thanks for any and all help!

 

When we converted my 61 to disc brakes with a dual system, we had to match the booster to the master. I had this done by "Booster Dewey" out in Portland. We explained what we wanted and he built the system and it all fit like a glove and works perfect
It was well worth the time and money to have him do it right
Mark

 

I upgraded my 55 to disc /drum and also installed a new dual master as well.

I think if you going to a dual set up you should take the time (less than day for me) to install disc up front

 

i got everything from summit for my 62 invicta,drum front and rear,buford owner from ct

 

I see no reason to ditch the massive finned aluminum drums that are uniquely Buick.

Care to elaborate on exactly what you got?

I'm going to start tearing into it tomorrow. Nobody seems to be able to source the '67 master/booster combo I was trying to get. I think the '67 master should bolt up and work with my current booster, so that's what I'm going to try first.

 

One thing you need to check is if your original master is a deep or shallow bore then use the same duel master. It will bolt right up to your original booser. I did the same thing on my 64' Catalina. It used the deep bore and I would assume your car will use the same deep master. Good luck.

 

I ordered the master with a shallow bore, since that is what was spec'd for a Delco booster. I'm going to tear it apart tomorrow, so hopefully I don't have to wait for a new master to arrive.

 

+1 on Booster Dewey - Good guy, knows his stuff.

Cameo Invicta - I'm with you on the drums, they work fantastic when set up correctly..I have 68 A-Body Aluminum drums on my 65, and they are beautiful, like a piece of art! The way I look at it, if you have to panic stop a 2nd time, thats YOUR fault....!!!!

You might want to check with Inline tube, they have some packages put together for various single cyl applications, and may have one for your car...I used them on the Corvair and the 65, and was happy I did.. nice to have all prebent and sized lines!

 

Well I didn't end up with what I expected when I took the master off. Turns out that the master cylinder piston is actually part of the booster. I had to disassemble the booster to get at the retaining clip that holds it in place.

However, after that extra work, it still looks like the shallow bore '67 master I ordered should work. Hopefully I can get the booster and master installed within the next few days and make sure everything works. Otherwise I'll be on the hunt for a new booster.

 

Good luck, I'm following this also as I will probably do a dual switch sometime down the road. Pardon the pun. :laugh:

 

Is your stock booster and master Moraine or Bendix? I think the Moraine is the one that uses the piston as part of the booster. https://www.dropbox.com/sh/q5c7cmjd...vrolet 1962 Shop Manual/06 1962 CH-Brakes.pdf

 

It should be the Delco/Moraine unit. No visible markings, however it is a anodized gold color, and there are M's stamped into the rear of the master cylinder studs.

 

I just changed mine over a few months ago. I used a booster from a '92 Suburban (because already had a good one laying around) and a master cylinder from a '80 Impala. I did have to cut the rod on the booster, thread it, then I used a female rod end to attach to the pedal. Also the bolt pattern where the new booster bolts to the firewall was slightly larger.
I asked around for the best was to do this and everybody I talked to had a different opinion. Some said use residual valves or proportioning valves and others said I didn't need them. So I tried what I already had, only had to buy the master cylinder. My car still has the original drum brakes all around and the brakes work great.

 

Got the booster assembled and installed tonight. I've never had one apart before so it was interesting seeing how it all worked.

I also got the master installed on the booster. Everything seems to work as intended. I've got about 1/8" of pedal travel before the push rod contacts the master cylinder piston, which seems to be about spot on from what I've read. Now I've just got to bench bleed the master, bend up the adapter lines, and bleed everything.

I've also got 2 new wheel cylinders for the front, new shoes all around, and had my drums re-surfaced. It should stop on a dime now!

 

If you have not already done it you may want to have your brake shoes re-arched. This was common back in the day of drum brakes. You should be able to find someone locally that resurfaces clutches and brake shoes mostly for commercial/industrial type vehicles, forklifts, trucks and other related equipment, that can preform the service. In the greater Seattle area we have a place called Friction Services that I have used for this service for the past twenty some years. You can read about arching here. Good Luck
http://model-a-wis.com/brakearc.pdf

 

http://inlinetube.com/disc brake conversion/DBK6603.htm WHEN I SWITCH OVER THIS IS THE PLACE I FOUND...LOOKS LIKE GOOD STUFF..

 

Everything is installed and plumbed. I didn't realize the rear line was 3/16". I thought it was 1/4" front and rear, so I had to get a different adapter line, but other than that it went smoothly. And for those that are curious, I incorporated the factory pressure switch into the port on the distribution block where the rear line originally went. I used a female/female adapter (3/16 brake line fitting x 1/8" NPT) and a 12" section of brake line. This puts the switch right next to the master, and within range of the factory harness.

All I have left to do is adjust the drums and make sure everything is properly bled.

And I also had to return the set of front shoes I got from Napa. They were terrible and didn't fit at all.

 

I had to rip everything back apart yesterday. There was something wrong with the booster. Now after studying things a bit more I think the original master cylinder piston actually partially sealed the power piston in the booster. Since I assembled everything sans piston, the power assist didn't function properly. In addition, without the old master cylinder piston the push rod had a tendency to move around a bit and wouldn't contact the new master cylinder piston in a consistant location.

Since I can't seem to locate a retailer with the proper reman'ed '67 booster in stock, I'm going to try to trim the original piston and use it as a sleeve within the power piston. That should hopefully properly locate the push rod and now allow for any deflection, and should keep everything sealed within the unit so the power assist actually works.

 

This project has officially gotten on my nerves.

Even after double, triple, and quadruple checking the re-assembly of the booster, it works, but only barely. Luckily I was FINALLY able to locate the proper re-man'ed '67 booster, which should be here Monday. I'm not sure if there's actually something wrong with my booster (in terms of assembly), as it holds vacuum and does provide some power assist, or if it's just too small for the new master? The booster spec'd for the master I'm using is 10 3/4", and mine is only about 8". In addition, the push rod doesn't seem to be quite long enough.

So I think my plan of attack is to mock up and install the new booster, and if necessary fab up and install an extension for the push rod to get the proper pedal height.

Once this thing finally gets finished I think my rear tires are going to severely suffer from my aggravation.

 

Where did you find the 67 booster? I have been looking for one my self for my 61 Olds. By the way I did this on my 63 Wildcat and you can use the booster from 63 up but getting a used booster is always iffy.