[1967Tempest]

Originally Posted by Scarebird

We make a semi-custom bracket that mounts the "BK" code 1985-87 dual 9" booster on different cars. The test car is a 64 Catalina; we will get some pics and post them. The later booster allows 66 and later masters to be used.

Would like to see them if you have them...



Also I swapped out the lines. Front reservoir goes to front brakes etc.. Car brakes were still VERY touchy. But I put 70+ miles on the wagon yesterday and the more that I drive the car the better they get. Meaning the feel of the pedal. I think that there might have been a lot of rust on the brakes or what ever, cause they feel great now.

I would still love to get a front disc set-up that uses 14" rims.....

[61 vent]

Scarebird, have you had time to take a few pictures of your bracket?

[mkoser]

I know this is an old thread, but I though I would bring it up again to seek feedback.

Does anyone that has done this conversion have any input?

I did mine in 2011, and have not had a lick of trouble since then. I've put a few thousand miles on. I've had no leaks, and no braking issues.

I still haven't cleaned up my "test-fit" brake lines to the master. I have work to do yet. I think I'm finally ready to throw my old single master in the trash. I held onto it "just in case."

Thanks,

[Keith Seymore]

Subscribing (so I can find this when I need it).

Just lost the brakes on the GP last night (single system). Made it home safely by downshifting the trans and with what little brakes I had left, but getting the car in the garage was a challenge!!

K

[Keith Seymore]

Some of you know that I was a brake development engineer for GM light truck at the Desert Proving Ground in the early 1990's timeframe. My (professional) experience is therefore limited to dual systems but hopefully it is still ok for me to make some general observations:

a) Not to put words in mkoser's mouth but it seemed implied to me the thread was to discuss drum/drum systems. References to disc/drum systems tended to confound the issue and probably should have been avoided.

b) References to the master cylinder port location should be made from the perspective of vehicle position. That is, the front port is the one closest to the front bumper; the rear port is the one closest to the rear bumper. Any other frame of reference causes additional confusion.

c) In my development experience, even within modern dual systems, there were some that were front to front and some that were front to rear, depending on other considerations like hood clearance and relative reservoir size based on vehicle platform* In those cases it was obvious what the intention was, since the large reservoir would be for the front disc system. My point is that I wouldn't be surprised if early cast iron dual master cylinders had similar variation and it would be ideal if the part itself could tell us which way it was to be hooked up, similar to my aluminum master/plastic reservoir analogy. Since we are specifically discussing a '69 Bonneville m/c I wonder if the '69 chassis manual would provide any insights...

d) I have the brake system release charts for all LD pickups, starting in 1969. I'll take a look and see if they reference which port feeds which brake system (front to front vs front to rear).

e) I believe this thread was an excellent resource and am glad it is still available as a reference.

K

*example - the old M/L Astro/Safari mini van. The sharp hood angle cause the rear reservoir (located toward the front of the vehicle) to be miniscule in height. I tried one of these master cylinders on my Chevelle and, while it worked well for pedal feel/effort/travel, the angle of the installation meant that I had to jack the rear of the car up in order to put brake fluid in the rear system or to bleed the brakes.

[Scarebird]

Originally Posted by Keith Seymore

Some of you know that I was a brake development engineer for GM light truck at the Desert Proving Ground in the early 1990's timeframe. My (professional) experience is therefore limited to dual systems but hopefully it is still ok for me to make some general observations:

a) Not to put words in mkoser's mouth but it seemed implied to me the thread was to discuss drum/drum systems. References to disc/drum systems tended to confound the issue and probably should have been avoided.

b) References to the master cylinder port location should be made from the perspective of vehicle position. That is, the front port is the one closest to the front bumper; the rear port is the one closest to the rear bumper. Any other frame of reference causes additional confusion.

c) In my development experience, even within modern dual systems, there were some that were front to front and some that were front to rear, depending on other considerations like hood clearance and relative reservoir size based on vehicle platform* In those cases it was obvious what the intention was, since the large reservoir would be for the front disc system. My point is that I wouldn't be surprised if early cast iron dual master cylinders had similar variation and it would be ideal if the part itself could tell us which way it was to be hooked up, similar to my aluminum master/plastic reservoir analogy. Since we are specifically discussing a '69 Bonneville m/c I wonder if the '69 chassis manual would provide any insights...

d) I have the brake system release charts for all LD pickups, starting in 1969. I'll take a look and see if they reference which port feeds which brake system (front to front vs front to rear).

e) I believe this thread was an excellent resource and am glad it is still available as a reference.

K

*example - the old M/L Astro/Safari mini van. The sharp hood angle cause the rear reservoir (located toward the front of the vehicle) to be miniscule in height. I tried one of these master cylinders on my Chevelle and, while it worked well for pedal feel/effort/travel, the angle of the installation meant that I had to jack the rear of the car up in order to put brake fluid in the rear system or to bleed the brakes.

You may be able to simply switch reservoirs, from say a 81-87 G body.

[MOJO Catalina]

Originally Posted by Keith Seymore

Subscribing (so I can find this when I need it).

Just lost the brakes on the GP last night (single system). Made it home safely by downshifting the trans and with what little brakes I had left, but getting the car in the garage was a challenge!!

K

Scary situation.. I lost brakes in my '63 GP pulling into a parking space at a grocery store.. Luckily there were bushes in front of the space that were about 5 feet tall and had been there for 10 years. I usually park just anywhere but on that day Chief Pontiac must have been watching over me.. The pedal grabbed for a split second then went right to the floor.. I sailed right into the bushes.. No damage, just bent the bush out the other side.. When I pumped the brakes a few times they started grabbing again.. the seals in the MC must have gotten some rust buildup around them, allowing the fluid to blow by them.. I abandoned the grocery run and drove home slowly with one foot on the Emergency brake... It could have been bad if I'd plowed into a car or someone and their cart.. Did the dual swap the next day.. ( car sold years ago) Now both my drivers have them. The '60 Cat is manual drum/drum and the '63 BV is power drum/drum..

[Keith Seymore]

Originally Posted by Keith Seymore

Subscribing (so I can find this when I need it).

Just lost the brakes on the GP last night (single system). Made it home safely by downshifting the trans and with what little brakes I had left, but getting the car in the garage was a challenge!!

K

Ok - so I've gathered all the parts and have started the teardown....and already hit a couple snags.

a) I'm using the Autozone M-1328 master cylinder for a '69 Bonneville. I've added the adpater fittings to the outlets and, when I position the master cylinder, I've got hard contact with the wheelhouse inner. There's not enough room to add a brake line and make the turn. Anybody else experience this?

b) The removed single pot master cylinder has a very deep bore in the piston for the push rod; the new master cylinder has just a small dimple to position the push rod. I'll need to take quite a bit off the push rod but - how does it come out from the booster? When I pull on it it comes out a bit but feels like it is attached to a/the diaphram and sucks back in when I let go.

c) I sent a note to one of the brake engineers relative to the port placement. He was off for the GM shutdown but I'll let you know once he replies.

d) Do you all have a preference - should I keep posting here or should I start a new thread specific to my conversion?

K

[Stuart]

I seem to recall that the push rod is either attached to the booster internals or is a separate part, depending on what brand your booster is - Bendix or Delco-Moraine.

[Keith Seymore]

Thanks, Stuart.

I found a vintage (1978) Delco Moraine design handbook which shows it clipped to the diaphragm.

I can probably rework it in place but I thought it would be easier to put the point on the end with it out of the car.

K

[ornjcr8]

no...no, keep posting with your project. I live by Rochester and once your get yours done I know you will want to come over and do my 62

[Keith Seymore]

Originally Posted by Keith Seymore

d) I have the brake system release charts for all LD pickups, starting in 1969. I'll take a look and see if they reference which port feeds which brake system (front to front vs front to rear).

Not particularly helpful but I thought it was cool to look at the old document (from back when everything was done by hand).

K

[64catalina]

On my 64 cat I believe the original pushrod was attached with a collar and pin w/clip.
New one had threaded rod and collar.

I have a question with all due respect to everyone here.
I have done the conversion on my car.
I am curious, why would you collect all the parts and pieces versus an established kit?
Not trying to stir up stuff just curious.
for me it was knowing I had what would work so I could be back on the road asap...

There is no good luck, its just what you make out of what you got...

[Keith Seymore]

Is there an established kit?

I have to stay drum/drum because I'm keeping the 8 lug aluminum wheels.

K

[64catalina]

I looked around a lot and master power brakes was the only one I found that would guarantee fit. disc upfront original drum in back.
uses calipers etc from a late 70'early 80's chevy all new parts with power $900 give or take
Came with everything but the ability to bend a really tight brake line..

[Keith Seymore]

Any input on why I'm crashed hard into the wheel apron?

It looks to me like I need ports on the inboard side of the master cylinder.

K

[1967Tempest]

Did you have manual brakes? Normally, the brake booster, (with power brakes) would move this up and out of the way. You might need a 90* adapter.

[Keith Seymore]

Nope - always been power brakes.

My parts guy said they don't make 90 degree adapters (which accept a brake line flare).

K

[1967Tempest]

Originally Posted by Keith Seymore

Nope - always been power brakes.

My parts guy said they don't make 90 degree adapters (which accept a brake line flare).

K

HMMM... I might have to say BS on that. If I get some time I will go to the "real" auto parts store and dig through the Weatherhead bin and see. Is that 3/8s in the front and rear of the new master cylinder?

[64catalina]

Those 90's are hard to find. I had the same issues.
also I did not want put distribution block far away.
Here's what i wound up with...