Master cylinder swap on 51 Mercury?

Is there some sort of known swap to upgrade the master cylinder on a 51 Mercury to a 'modern' (post-67) dual reservoir design? Not looking to put a booster or master cylinder up on the firewall...would rather find something that will fit in the location where the stock, original master cylinder is???

Any one of you Merc guys done something like this???

 

Checked the Brake Bible, my Wagner book and that is a 1" bore MC. Front wheel cylinders are 1 1/8" and rears are 1". An exact match in bore size is a 67-70 Chevy Truck half ton MC Wagner PN F64885. Used the same front shoes 11x2" and the rear on the Merc is 11x 1 3/4" Should work fine..........damn I love looking this stuff up!

 

that sounds great on paper,,

....but i am pretty sure a 67-70 chevy MC does not mount the same way a 49-51 mercury does under the floorboard....much less the way the pedal articulates....

 

The Mercury master cylinder isn't really under the floor, as it is on most early Fords...It IS low-mounted, though...sitting at the bottom of the engine compartment in front of the firewall area. Not real accessable, but better than being under the floor and behind the pedal assembly! You can see it if you look down next to the motor on the driver's side.

The pedal comes up through the floor, though...like on early Fords.

 

Before I went to power brakes, I had a fatman bracket made just for your application. Manual brakes but with a dual master cylinder. The bracket is a good design, you don't need to change any pedal stuff or even the original pushrod. It does relocate the new m/c higher because the brake lines come out of the left side of the m/c. The higher position is so the lines can be high to clear the frame.

 

That sounds cool to me. Is it an existing Fatman product, or was it a one-off custom job?

I'd like to be able to keep the stock pedal, etc...but have the benefit of a safer, dual reservoir master cylinder on the car. The stock drum brakes stop the car fine, and the pedal effort is almost nill, so I'm not concerned about adding power brakes at this point.

 

I would also like to know - I bought the conversion kit to replace witha dual MC and a power booster but have yet to install. The instructions are not clear and I know it will be a weekend issue cutting on the chassi. If there is a better way i would love to know!

 

Maybe the A-1 10-1485 Mustang mounts with two ears has a 7/8 bore if it's a new one. Stops my coupe with F 1 and 8 inch Ford rear My 2 c's

 

That is funny how my sentence could read it was custom made. No, it was an off the shelf part. But I just went to the FATMAN Fab site and noticed it is not listed anymore?? I bought this simple bracket more than 10 years ago. Maybe they still make them but don't list them. It was just a bracket that bolted to the original holes on the frame for the original m/c. Then there was a 90 degree plate on this fatman bracket that you could bolt the manual mustang m/c to it.

 

Of course but as noted changing mounts is rather easy.

 

Ha Ha...I get it now...I wasn't sure if you were saying the mount was custom made or not.

I'll call Fatman and see if that bracket is still available...could be just what the doctor ordered!

Thanks!

 

Just called Fatman to order the bracket. It's still available and runs $70 shipped. The guy says it bolts a 74-78 Mustang II manual brake master cylinder to the 49-51 Mercury brake pedal assembly.

My only concern now is...will that master cylinder work right with the stock Mercury drum brakes? A Mustang II uses a disc/drum arrangement instead of four wheel drums. At the very least, I'd also need to add a residual valve to the front brake line plumbing, correct? (the residual valving is often built into the master cylinder's drum brake output as I recall).

Or...is there a low-buck disc brake swap kit or adapters out there for the stock Mercury spindles??? That might be an option, as the car needs all new linings (shoes) at the moment anyway??

 

I played it safe and put in the 10lb residuals in both lines when I put my kit in. Later when I changed to power m/c, I sold the fatman bracket and m/c to a friend. He never bothered putting in the residual valves and he said he never had a problem. That fatman bracket puts the m/c pretty high up on the frame, it must be at least 8 to 10 " above the bottom most point of the frame. So, maybe there isn't that much gravity action pulling the brake fluid down away from the wheel cylinders.

The JAMCO website advertises a 49-51 disk kit that doesn't require spindle machining. That is a big marketing feature, no body offered a bolt on kit like that before. Specifically that you could use without modifying a arms, uprights, spindles. You still would need a dual m/c anyway wouldn't you for that? I don't think the stock single m/c has enough volume to run a disc caliper.

 

I'll have to see how much room there is to move the master cylinder upwards from it's stock location. There's some room above it, but then the exhaust manifold and pipe come into play if you go TOO far.

No, the stock single reservoir master cylinder wouldn't work with disc brakes...it doesn't hold that much fluid at all...not nearly enough for even a small disc brake caliper.

I was able to order new brake shoes for the front from the local parts store (Murray's) this afternoon, so I'll keep the stock drums for the time being.

My brother-in-law thinks that most Ford mastercylinders will interchange as far as the mounting goes, so we're thinking that I could go with a 1967-70 Mustang drum/drum master cylinder in place of the Mustang II one on the Fatman bracket. I think that would be the best answer if it interchanges directly.

 

You're right on top of things. I also made a heat shield out of an aluminum plate that sat between the exhaust manifold and m/c. The fatman bracket put the m/c right next to the joint where the exhaust manifold (SBC) connects to the exhaust pipe.

 

This one's got a 289 Ford in it with the rear-exit manifolds. Probably a pinch narrower than a small block Chevy, but it'll need a heat shield as well if the new master cylinder is up much higher. Thanks for the inside info so far!

 

Used this type master on my '51 using the Fatman/ECI bracket.
It's late 60's GM drum/drum and has the residual valves built in (no unecessary plumbing) Found that there was interference with the steering box when trying to use the Mustang master. This to me is a better choice if you are using original drum/drum setup.

 

I have never seen a cap like that! All m ine had the wire bale

 

In fact the one that was used on the car had the bale wire. Other than the cap they are identical, probably different vintage.

 

Anyone know how that Fatman bracket will work if you are running the stock Flathead? Any problems with exhaust?

 

There should not be any problem. It puts the new master almost in the same place as the original.

 

Is that master cylinder pictured the one from the 67-70 Chevy/GMC pickup that T-man mentioned? Or is it from a late 60s GM car (Chevelle, Nova, etc)??

 

They are pretty much the same shape and size regardless. You can look at the pictorial guide and see where the ports are located based on app.

Good luck man.

 

have been paying attention to Merc/brake issues for a while as my brother bought Feders coupe.....hence saved the following from a previous thread that I can't find just at the moment...Note: they're alliance members...

http://www.jamcosuspension.com/products_suspension.html

1952-53 Mercury Passenger Cars


The Jamco Disc Brake Conversion kit bolts to your Stock Spindles without modification. Kit includes new 4-1/2" Bolt Pattern Rotors* (Disc Brake Spec¹d Wheels REQUIRED); new Calipers and Pads; Caliper Brackets; Caliper Hoses and Brackets; Bearings, Seals and Dust Caps.
*GM 4-3/4" Bolt Pattern Available.
P/N FM-4953DBC @ $525.00
We do make bolt on disc brake kits for the 49-51 & 52-53 Mercurys. We also do the Ball Joint conversion for both. I do want to appoligize that our website pricing is not correct. We are building a new website that is nearing completion. Our new site will be a secured commerce site with suspension and brakes for all your needs. Please contact us for the current prices.<o></o>
<o> </o>
With our kit, you do not have to machine anything. It is a true bolt on kit in the 5 on 5 1/2" bolt pattern. All you will need to do is clean up your spindles and bolt our kit on. We have machined new bearing races to fit the stock spindles.<o></o>
<!-- / message --><!-- sig -->__________________
JC Genty
Jamco Suspension
ph #951-549-1441
fax # 951-549-1446
www.jamcosuspension.com
*Proud Member of the Alliance

Cheers,

Drewfus

 

someone post a picture of the fatman bracket. my friend has a '50 merc and i was thinking about making a bracket (the master bolts to the frame with 2 bolts through the lower part of the master). you can find a different master with a illustrated guide (i have a early 90's wagner book off of ebay for $5). the bolt on style caps are getting harder to find but in most cases they're shorter, so if you have room for the bail lid then use it. i made one for my '47 ford but that was an easy straight shot, it looks like the inside ear of a new style master will hit the frame.

 

Our new website is now up and running. The 49-51 Merc kit is on the front page. All pricing on the website is correct. As mentioned above, these are true bolt on kits. no machinging on your part is required.

 

here you go...

tok in the house.

 

TOK = THE MAN

Thanks!

 

Simple, yet effective!

Thanks, Toker!!!

 

Not a single problem with the exhaust, I do have fenton headers on my flatty.