Rear wheel cylinder port swap?

[Larry Callahan]

Long before we bought our 1930 Model A someone added hydraulic brakes.


Like so many others the rear wheel cylinders are at the bottom and are difficult to bleed due to the bleeder screw being at the lowest point.


Has anyone ever seen a wheel cylinder with the ports that are reversed? Maybe something out of another car or maybe one that's easy to modify?


My day job is at a machine shop and I am half tempted to make my own from scratch.

[johnneilson]

I just install mine at the top

[Bob C]

I've seen the cylinder swapped side to side but I think
you have to redrill some of the holes in the backing plates.

[Larry Callahan]

Originally Posted by johnneilson

I just install mine at the top

Any chance you can share a picture? I have always believed that you can't do that due to the leaf spring.

[Larry Callahan]

If I swapped them from side to side the bleeder port would still be at the lowest point.

[nkaminar]

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On one car I took the steel tube a little loose. It was at the top. No air in the cylinders.

One alternative would be to pump brake fluid in the bleeder port and have to tube loose at the master cylinder.

Any change that the cylinders could be turned up side down?

[Martinbuilt]

There are a couple hotrodder solutions to that.
I think the shock ball is the issue. Someone using tube shocks would cut those off and put the backing plates on right side up.
Another fix is to redrill the 4 mounting holes. You position the backing plate at 11 o'clock, and get enough clearance for the bleeder.
It may also be necessary to cut a small recess in the backing plate. (It's been a while since i've looked at this mod)
If you leave them at the bottom, you can swap left for right and rotate them so the screw is on top.
However, there's some work, as the mounting holes and the big round boss are not centered. I've seen videos of guys cutting a moon-shaped sliver out and welding it in 180° out.

[30Murray]

Les Andrews volume 2 (green book) has all the details, basically what is described in post #7.

[larry harding]

i put hydraulics on my speedster project. yea the wheel cylinder is at the bottom. bleeding was a little trouble, but not bad enough to worry about

[ModelA29]

My Cessna 182 had the bleed screw at the bottom. You just took the cap off the master cylinder and hooked a hose on a squirt oil can to the bleed screw and pumped any air back into the master cylinder.


https://youtu.be/1haS13YyJRE?t=63

[Bob C]

Here is a picture of the wheel cylinder at the bottom and the bleeder at the top.

[Larry Callahan]

Originally Posted by Bob C

Here is a picture of the wheel cylinder at the bottom and the bleeder at the top.

Oh!!!! What cylinder is that?


Any chance you know what it's originally from or a part number?


Thanks!

[Bob C]

Those are the original wheel cylinders. You switch them from side to side move the big hole in the backing plate up a little and drill new bolt holes.

[Larry Callahan]

Originally Posted by Bob C

Those are the original wheel cylinders. You switch them from side to side move the big hole in the backing plate up a little and drill new bolt holes.

Forgive me if I am missing something here but, isn't the bore / piston a different size on each end of the wheel cylinder? Turning them around makes the different bore sizes face the wrong way?

[Bob C]

You have left and right hand wheel cylinders so you can orient
them the way you want.

[Mitch]

Larry
I have a coupe that had hydraulics. So, I rebuilt everything new cast iron drums, master cylinder, wheel cylinders, and welded the shock balls where they belong. Didn't have all the original parts to go back to mechanical. Anyway, I can take pictures tomorrow and post them. It work very well. Now my roadster is all original and I wish the coupe was also.

[Larry Callahan]

Originally Posted by Mitch

Larry
I have a coupe that had hydraulics. So, I rebuilt everything new cast iron drums, master cylinder, wheel cylinders, and welded the shock balls where they belong. Didn't have all the original parts to go back to mechanical. Anyway, I can take pictures tomorrow and post them. It work very well. Now my roadster is all original and I wish the coupe was also.

I would LOVE to see pictures.

Thanks!

[JayJay]

Originally Posted by Larry Callahan

Forgive me if I am missing something here but, isn't the bore / piston a different size on each end of the wheel cylinder? Turning them around makes the different bore sizes face the wrong way?

Don’t have any experience with early Ford brake cylinders, but I’ve never seen asymmetric cylinders on any other car I’ve worked on.

[Larry Callahan]

I have not worked on many cars with drum brakes but every one that I have ever touched had asymmetric bores. I never measured mine. I will blow it apart this weekend and see if I can find numbers to 100% confirm. Oh!, maybe they are only different on the slightly newer Bendix self adjusting style.

[Mitch]

These should be pictures of the left rear. I believe the ones on this are 1948 hydraulics but not sure. It is tight but works just fine. I plan on going back to mechanical after I finish a roadster.