My Master Cylinder is leaking on my model A and i want to replace it. I cant find the same push rod on other applications and i cant get this rod out. any ideas? the MC seems to be from a Mustang or something similar. I have drums front and rear.
Defiantly the wrong master for a drum drum set up, like said, both reservoir's should be the same size.
yes i realized the master is for a disc drum setup that is also part of the reason i do want to change it. and there was a dust cover but i have the rod apart already and threw it back together for pics. thanks to those that helped with suggestions.
There is an expanding ring in a groove on the push rod that holds it in the piston. You have to pull out really hard. Even then, I have had some not come out. A drum/drum Mustang unit would go in there too.
I have advised a bunch of Ford guys on a dual master conversion for drum/drum cars,go to www.rockauto.com and get a Bendix 11485 (new)$41.79 this will have a separate pushrod with it or the Autozone rebuilt is a FENCO M1485 $20 exchange(many of these are Bendix cores) their new ones are mostly import **** as are the Raybestos at O'Reillys.The master you now have has had the pushrod modified so it can be adjusted for length,Summit and other vendors sell the kit for that,stock pushrods are non-threaded.
Wrong,some Ford masters for drums will look the same, the internal bore length is the difference.When you look at the rear of the master you will see the depth of the piston is different between disc and drum masters.The one He needs is a Bendix 11485 which in a new one has an equal bore see Pic
You're right about some Ford/Bendix drum/drum master cylinders looking like disc/drum with different sized fluid chambers, as many drum/drum masters are not 50/50 in operation, just like disc/drum. One example is a '68 F-250 drum/drum. You are wrong, however, about the primary piston push rod bore. Most Ford/Bendix (and others) manual masters have a shallow bore with a retainer to capture/retain the push rod, while most power brake masters have a deep bore to make sure the booster push rod does not fall out, as the push rod cannot be retained to allow removal of the master from the booster.
The rod will come out. There is a spring steel clip that holds it into the piston and it is hard to pull it out once it snaps into place. When you put the new one in place make sure that it snaps back into place. If you don't it will be too long and prevent the piston from returning. My buddy had that problem when he replaced his M/cyl. The brakes eventually locked up. Later in the day he stomped on the pedal and it snapped into place fixing his problem. That tells me it's a Ford M/cyl. I Agree it looks like a disc drum M/cyl I should know it by sight (I've sold more than a few but the new ones all run together for me.) it looks like a 68 disc M/Cyl for a full size Ford.
Just not true. In fact, it's better to use a disc/drum master with drum brakes. OK- 1-There were more produced and are easier to find. Car/lt.truck drum/drum brakes were all but done by the mid '70s, or for less than ten years total, with tandem masters. 2-No question which chamber (larger) goes to the fronts. 3-A future front disc upgrade will not require a master cylinder change. JFYI, many drum/drum masters have unequal fluid chambers, because they are not 50/50 in operation. There is a good reason the outlet ports are different.
I know this is an old post, but I am researching my application for manual drum/drum brakes,(stock '40 ford) and here is what I take from this discussion. I have purchased a Bendix 11485, it looks like the one in Tommy's post, not like the one in jeffB2's post. All of my hands on searching for the Ford C9AZ-2140-D (Bendix 11485) are of the unequal reservoir size. My reservoir, in hand, does NOT have equal reservoirs, and the outputs are different sizes. Posted here "No question which chamber (larger) goes to the fronts.", on the M/C I have, the rear has the larger reservoir and smaller fitting. The Front has a smaller reservoir and a larger fitting. To be clear the rear M/C port is for the front brakes and the front M/C port is for the rear brakes? I have stock drum/drum and future F1 front drum/stock rear.....Old skool. Are there any flaws in my logic?
Correct. The larger reservoir goes to the front brakes, regardless whether primary or secondary, or outlet port size.
It all depends on how light the Model A is in the ***. PU truck masters are sized differently than cars. I would go with a '67 Mustang master myself.
The Jalopy Journal
