Hydraulic Brake Conversion

[8EL]

So after diligently following Model A Ford Mechanics Handbook Volume 2 authored by Les Andrews directive on installing hydraulic brakes on the model A, I wonder how are the brake lines to be plumbed?

The backing plates are rotated 16 degrees to clear the spring shackles, but how are the lines to be routed? Has anyone followed this procedure? When I bought this car the wheel cylinders were on the bottom to solve the spring clearance problem. But in that position the bleeder screws were on the bottom so getting the brakes properly bled was next to impossible......

Looking for someone who has followed the procedure described in this manual, and what was done to plumb the wheel cylinders....

[nkaminar]

My Model T had hydraulic disk brakes at the rear (no front brakes). There was a flexible cable at the ball joint at the front of the differential. From there a solid line ran to the banjo and a tee branched off to solid lines to each brake. The cylinders for the shoes were mounted up side down so I had to remove them and turn them right side up to bleed them, leaving the steel lines connected. That might be impossible with drum brakes.

[rotorwrench]

The info in the previous post is same as the 1939 through 1948 basic systems. The radius rods forward down to the wheel cylinders aft should be hard lines. Place the lines in the best protected part of the radius rod to prevent damage from below. The brass T fittings from the 39/40 or 41/48 can be used along with a flex line to the forward end of the radius rod connection to the torque tube. Study the later systems that used hydraulics for placement. Mac VanPelt's web site has the parts illustrations for all the early V8 years.
http://www.vanpeltsales.com/FH_web/F...m_1939to42.jpg

[ModelA29]

In your 4th picture it looks like you'll need to grind some room to get the line and a wrench to the wheel cylinder. In the old days we'd just go to the parts stores and start opening boxes until we found one with the line in the right spot at the right angle. On my airplane the bleeder was at the bottom and you reverse bled it with a squirt oil can.



Bleeding starts at 4 minutes - https://www.youtube.com/watch?v=SL0aotYplfw

[8EL]

The whole reason for moving the wheel cylinders to the top was to be able to properly bleed them. I had limited success in achieving a good pedal with them on the bottom, even trying to power bleed them and just cracking the bleeder. The instructions that I followed did move the wheel cylinder to the top. They were to be indexed to sixteen degrees from vertical, which mine were. Looks like they would have cleared the spring shackle mounting strut if that would have been twenty degrees.

I was wondering if any one else had run into this issue. More of a hinderance I guess than a problem for as "Bridgeport taketh, Lincoln giveth" ....Just a nuisance to have to weld the holes back up and redrill four degrees ahead..... Id rather not be grinding on the forging.

[Phil Brown]

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It looks as if it was rotated in the other direction the brake line would point away from the shock mount. Kinda looks like it is pointing straight at it now

[Kurt in NJ]

some new wheel cylinders don’t have the bleeding hole going to the top, it ende 1/3 the way down the cylinder due to bad manufacture, I learned to take apart and inspect every one, even rebuilt( resleeved ones still had grindings in them embedded in the rubber cups

[8EL]

Originally Posted by Phil Brown

It looks as if it was rotated in the other direction the brake line would point away from the shock mount. Kinda looks like it is pointing straight at it now

The larger of the two pistons has to face forward, if you move it to the other side to point the port forward it will put the smaller piston to the front. Same thing if you rotated it 180 Degrees and left it on the same side, it would also put the bleeder on the bottom.

[8EL]

Relocated one allowing enough room to plumb the line. The bleeder could still be considered on top and effective for its intended purpose. Might have to heat and re route the emergency brake cable tube up a little on the exterior side?

[Jim Brierley]

I did my first conversion to hydraulics in 1959, and have done 3 since then, and I have never rotated any backing plates. It becomes a bit restricted, but is doable. Always use steel line or special tubing made for brake systems. I believe it is Volvo that makes tubing that is made for braking systems, but looks more like copper and doesn't rust, we use this on our Bonneville racer.

[ursus]

I think Jim Brierley is referring to Cunifer tubing which is a copper-nickel alloy that is more easily bent into the shapes that would permit installation in the tight quarters of an installation that avoids the need to rotate the backing plate. More expensive but worth the cost, in my book.

[8EL]

All backing plates need to be rotated if installing the wheel cylinder on top. Otherwise the cylinder will fall directly in line with the spring mounting strut. Les Andrew's book called for it to be rotated 16 degrees which was not enough as can be seen in the pictures sent. The flare nut would not even clear the strut to start it in in the cylinder. If this conversion was being done without rotating the backing plate, then they were swapped side to side allowing plenty of room, but they would then be on the bottom with the bleeder on the bottom. Which I was trying to get away from....

I always have used steel line and double flared connections on brake lines.

[Y-Blockhead]

I used Cunifer brake line when i replaced the brake lines on my '55 Ranchwagon. Easy to work with and rust/corrosion proof.

[Gene F]

What happens if you swap the wheel cylinders from one side to the other? That way you can use a socket, or wrench to bleed, and bring the lines in to them.

[Y-Blockhead]

Originally Posted by 8EL

The larger of the two pistons has to face forward, if you move it to the other side to point the port forward it will put the smaller piston to the front. Same thing if you rotated it 180 Degrees and left it on the same side, it would also put the bleeder on the bottom.

Originally Posted by Gene F

What happens if you swap the wheel cylinders from one side to the other? That way you can use a socket, or wrench to bleed, and bring the lines in to them.

I think he mentioned the larger cylinder has to face forward? I am not familier with that type of cylinder.

[rotorwrench]

Spring over axle mounting was discontinued after the end of model A production. It's always been a work around to put hydraulics on the model A. The other problem is an emergency brake connection. It has always complicated the conversion.

I prefer the mechanicals myself but to each there own. I'd put hydraulics on a hot rod but it would likely not have a spring over axle suspension.

[ModelAArmy]

I am considering hydraulic brakes but this discussion complicates my decision since there seems to be many problems. If you purchase the Boling brake conversion kit, does it have these problems too.

[8EL]

Originally Posted by Gene F

What happens if you swap the wheel cylinders from one side to the other? That way you can use a socket, or wrench to bleed, and bring the lines in to them.

Yes, if you move it to the opposite side, you will have to locate it on the bottom to maintain the larger wheel cylinder piston towards the front of the car. That is what whomever first installed these type brakes on my car did.

I think increasing (as illustrated) the offset from the 16 degrees outlined previously to provide the necessary line clearance is the best option. This should afford good bleeding function while maintaining proper wheel cylinder / brake shoe orientation as originally engineered.

[8EL]

Originally Posted by rotorwrench

Spring over axle mounting was discontinued after the end of model A production. It's always been a work around to put hydraulics on the model A. The other problem is an emergency brake connection. It has always complicated the conversion.

I prefer the mechanicals myself but to each there own. I'd put hydraulics on a hot rod but it would likely not have a spring over axle suspension.

I thought that Henry kept his "Buggy Spring" design until the Deuce took over and came out with the "All New Ford" in 1949?

[AzBob]

Originally Posted by 8EL

I thought that Henry kept his "Buggy Spring" design until the Deuce took over and came out with the "All New Ford" in 1949?

X2, I thought the same as well.


1939 to 1948 Ford rear axle drawing.