Anybody switched to a dual reservoir master cylinder?

I finally found one thru O'reilly's. Napa, Autozone, and Advanced couldn't get the booster or master/booster combo. I would call and double check that they have a warehouse with them in stock. I've had a lot of vendors this summer accept orders for parts, and then inform me 3 or 4 days later that the stuff I ordered is no longer available. Frustrating to say the least!

 

wow, makes me glad I kept all the dual brake stuff of my '67 skylark when I parted it out. My '66 has a single and I was going to refurbish it all and swap it down the road.

 

Please take a picture of the booster and post when you get it. I just looked at the ones they offer for my 61 olds, 67 year boosters and I might go with the one for front discs. What kind of core charge is there. 15-45 for these.
Thanks
Pat

 

Will do Pat. Mine had a $29 core charge.

 

Everything is finally installed and the brakes work great! I had to enlarge the hole in the booster push rod to fit the brake pedal, but otherwise no further modifications were necessary.

I'll post some installed pics later, but here is a link to the booster I used: http://www.oreillyauto.com/site/c/d...ake+booster_1319138_-1&keyword=brake+booster# .

It says its for a disc/drum car, but I've seen other sources list it as a drum/drum application as well. Either way it works well so I can't complain!

 

Andy,

Any chance you could grab some cell phone pictures? I'm interested in doing this on my 1964, and this thread has more information than most. Regarding your master cylinder, by shallow bore, was it the 1" bore? Also, does your master cylinder have separate bales for each reservoir that go left right, or just one that goes front and back?

 

Sure Joe, I'll try and get it uncovered today or tomorrow and snap some pics.

In terms of the master there were two styles used, a unit for the Delco/Moraine booster, and a unit for the Bendix booster. The Delco/Moraine style had a shallow bore, as the booster push rod was much shorter. The Bendix style had a very deep bore, as the booster push rod was quite long. It is a 1" bore.

It only has separate reservoirs for the front and rear.

 

To fill it with fluid, do you snap off one wire (bale) or two?

 

Sorry I never replied Joe. I thought I did!

To fill it with fluid, there is a bolt that holds the entire cover in place. See the attached pictures, and it should clear up any confusion.

Not sure why it's flipping all the images, but it should give you a general idea.

 

I have a 1961 Buick Lesabre with a single reservior master cylinder with manual brakes. No power booster assist. Been sitting 12 years. I would like to convert to a dual reservior master cylinder for safety sake. I lost brakes on a 60 Nash Rambler one time. It was an interesting experience I would not like to repeat. My question is does anyone know a source / part number for a dual master cylinder with manual brakes? It's a big heavy car and I want it to stop safely. I don't know if parts are available to convert it to dual reservior with power booster. Thanks.

 

From my experience, you should still be able to use a master cylinder from a '67 big car like I did. As far as I'm aware, the only real difference is the pedal ratio, not in the master itself. For the one I used, they also included a rubber boot in the box for a manual brake pedal push rod, so it should work in either application. The only thing you'd need to double check is whether your factory master has a deep or shallow bore.

 

This is a mod I would like to do to my '61 some day, but for now there are too many other things that need to be done. Is it as simple as installing the new master and redoing the lines for one line to a distribution block for both back brakes and one line to a distribution block for the front, or is it more complicated than that?

 

The front port on the new master gets plumbed to the factory rear line with an adapter. The rear port on the new master gets plumbed to the factory distribution block. The now un-used port on the factory distribution block (where the factory rear line originally went) gets plumbed to the factory brake pressure switch, with a section of brake line. Fairly simple once you figure out exactly how everything has to be arranged.

The difficult part comes with getting the master/booster/brake pedal to work together. Although I tried it at first, it's not a good idea to try and use the factory early style booster with a later master. They aren't meant to work together. The best and easiest solution is to source a later master/booster combo, if you can find one. In the case of manual brakes, I cannot comment directly, but I'd assume it would be easier and should just bolt up, and be plumbed as I described above.

 

Like dadio55, I've got manual brakes, so it sounds pretty easy. Assume the brake switch line can be routed to a location convenient to get to up front with an in-line block to connect the switch to. So getting the proper master would be the most difficult part I can see. I've been looking on Rock Auto and see a couple that might work. Thanks!

 

This is the master that I used; http://www.autozone.com/autozone/parts/_/N-8kn47?itemIdentifier=227074_0_0_2877,92231 .

For the brake pressure swtich I used a female/female adapter (3/16 brake line fitting x 1/8" NPT) and a 12" section of pre-made brake line from Napa. And I just bent it so the switch sits right next to the master.

 

This is the one I was looking at, it's for a '67 Olds Delmont with manual brakes.

http://www.rockauto.com/catalog/moreinfo.php?pk=964517&cc=1346127

The bore is 1", same as mine I believe.

 

Now that I looked at the service manual diagram, I see what you mean on plumbing. I thought at first I could not use the original distribution block, but I forgot all about the brake light switch. I think I can get away with using just 3 short lines and a union for the back brakes. Pretty slick.

 

As I've been doing my mountain of research, I've been looking at measurements off Centric Parts on RockAuto. Generally you want to match the bore size, but you also have the push rod depth to consider. On manual brakes if the linkage stays on the car and is adjustable, I wouldn't guess it would be an issue and you would only have to deal with the difference between short "dimple" pushrod and deep.

I've purchased a booster to go along with it, but this is what I am going to use on my 1964 Wildcat, but Bendix brand (for a 1967 Wildcat with drum/drum):


For reference here is a 1964. Note the (small) difference in pushrod depth. I have no idea how this affects real world, but I assume the deeper the push rod depth the more pedal you are going to have to put in for the same braking effort.

 

That looks identical and has the same specs as the one I used, just from Dorman rather than Fenco.

It really is pretty slick. A lot simpler than I initially thought it would be. If you look a the pics above, you should be able to see how I actually routed everything at the distribution block.

Did you purchase a Bendix or Delco booster? The push rod depth listed for the original master is deceptive, because the push rod and master cylinder piston are actually an assembly. With the later style master/booster, they are separate. If you ordered a Bendix booster, than the master cylinder you posted will work. If your ordered a Delco booster, than you need the master cylinder spec'd for a Delco booster with drum brakes, which I linked below.

 

Hasn't been that long since I put a new master cylinder on mine so the memory is fresh. As I recall, the depth matches the one from the '67 Olds pretty close. Of course if some alteration of the push rod is necessary, I would think that shortening would be preferred over making it longer.

Something I had not considered is the different line and fitting sizes, but that should be a simple fix as in-line and conversion blocks are available in most sizes.

I also made a simple diagram of how Andy said to hook up the new master cylinder. Keep in mind it is a very simple diagram, I never claimed to be an artist.