More about the Brake Conversion

Bleeding the brakes was difficult for a couple of reasons.
1. I had not connected all of the brake lines. I guess it was sort of a "I'll do it later", but forgot.
2. I had a few leaks. I hadn't tightened all of the connections.
3. The crappy one-way valve I bought for bleeding at Harbor Freight Tools (I know, I know, Harbor Freight sucks) was leaking.
4. It takes a lot of pumping to clear the air out of completely empty lines. A LOT of pumping.
5. Once I had completely got everything bled, I noticed a leak on the line going into the power brake booster. As I tightened it, I stripped out the threads on the brass fitting. Finding a replacement part was somewhat difficult - none of the catalogs carry the part (some of them have a part number, but none of them carry it), and getting the specs for the part was pretty hard. Eventually I found someone who knew the weatherhead part number. From that, I found an auto parts store here in Austin that had it. The part I ended up installing is Edelmann 265301. 3/16 inch female thread, 1/2 - 20 male to go into the booster.
Now everything is back together. The brakes work well, but are still a little spongy. The power booster is working quite well.
Anyway, here's some pictures.
The replacement fitting is on the top center part of the picture, going into the booster.
Here's the new dual chamber master cylinder:

Below, the pictures are the left front rotor and caliper, right front rotor and caliper, and a couple of pictures of the car.

Brake Conversion Complete (almost)

The disc brake conversion is complete (mostly).
Once I got all of the parts in, the first thing I did was replace the pads and cylinders on the rear brakes. This was fairly simple, but there was quite a bit of grime on all of the parts. The pads were not completely worn, but the wear was uneven, probably because the springs were not installed correctly.
Once I had the rear pads replaced, with the new cylinders from the disc brake conversion kit installed, I replaced the brake lines on the rear axle. This took a bit more time than I thought, since I had failed to order the flexible rubber hose that attached the brake line on the frame to the rear axle.
Next, I painted and mounted the rebuilt power brake booster. I did this first to get an idea for how all of the new brake lines needed to be installed.
Next, I removed all of the parts from the front drum brakes. Since these were not going to be reinstalled, I didn't bother cleaning them, but I did keep them (since replacement drums are quite expensive).
Finally, I removed the master cylinder and the rest of the brake lines. I found the broken brake line on the front right side (which was the cause of loss of brake pressure which triggered this project).
Next job was to install the new front brake discs and calipers. I started with the front left since it was at a more convenient location in the garage. On my first try, I installed the mounting plate, and installed the brake caliper. However, I installed the brake caliper on the wrong side of the mounting plate, and was not aware that I needed to grind down a minute portion of the spindle before the installation. After grinding it down a bit, the mounting plate and caliper installed correctly.
Of course, the caliper needed to be removed before installing the rotor (but was necessary for making sure it fit). To install the rotor, I needed to pack the bearings, which was a new experience for me. I found some very helpful youtube videos that showed how to do it without special tools. Only time will tell if I did it entirely correctly.
Once I was sure I had the left rotor installed, I installed the right front, which considerably less difficulty.
Next I installed the new brake lines. One of the brake lines, the rearmost line attached to the frame, I was unable to remove. This seems to be because the lines were designed to be installed before the body was attached to the frame. Thus, I could not get the old line off without bending it out of shape. If I was going to have to damage the line removing it, I was not going to be able to install the new line without damaging it, so I just left the old line in.
The disc brake conversion kit has a dual bowl master cylinder. This is a massive safety improvement, but it meant that the front and rear brake systems had to be separated. This was accomplished by simply removing the line connecting one of the frame brake line blocks to the front left brake. The unused connection on the block was plugged with a part from the conversion kit. Note: this means the power brake booster only works on the front brake system. The rear brakes are still manual.
After I had all of the brake lines installed, I needed to bleed the master cylinder before connecting the lines. This was done with a kit that I bought at an auto parts store.
Another thing to note: not all of the crush washers I needed for this job were supplied with the kit. This was because I did not already have the power brake booster installed, and was not strictly a deficiency in the kit.
Next post I will go over the issues I had (and am still having) bleeding the brakes.

Left Rear Brake Drum

Since I was unable to make progress on the power brake booster rebuild, and I found a place that would do it for only $50, I mailed it in.
In the mean time, I took a look at the left rear brake drum. It was pretty dirty in there - lots of road grime. That's not too surprising, since the brakes haven't been done in probably over 20 years. The rear brake pad had some uneven wear on it, which if memory serves me, indicates that the springs are unevenly worn. That's not so bad, since replacing the springs on both rear drums costs about $7. The brake cylinder looked pretty bad on the outside, but once I got it taken apart, it was in surprisingly good condition. There wasn't much fluid in there, which isn't so surprising, since the hydraulic system seems to have lost pressure. There didn't appear to be a significant leak in the left rear wheel.
I'm predicting that I won't find a definitive cause to the loss of pressure - the entire system probably died from a million little pinholes. If the rest of the wheels are like this one, the amount of fluid loss of all of the wheels was probably enough.
In any case, I am going to be replacing all of the brake lines. The disc brake conversion for the front includes brake cylinders for the rear wheels. Once the power brake booster is back from the rebuilder, and get the parts I'm ordering in, I should be able to start and get the work done in a couple of weekends.

Power Brake Booster

I'm rebuilding the power brake booster for my 1956 T-bird. I have been driving the car for 18 years, but the booster has been out since at least before then.
As you can see, it's in pretty rough shape. Also, if you've seen the 1956 Ford Shop Manual, you'll notice that it really doesn't bear a lot of resemblance to the one in the diagram (page 215, Fig 15). I'm not sure if this discrepancy is because this part doesn't really belong in this car (not likely, my Dad is usually pretty reliable about this stuff), or, the design changed during the design year or the Thunderbird was different from the standard 1956 Ford.
Anyway, here are the steps I've completed so far:
1) Removal (this probably happened over 20 years ago, so I don't know how this was done)
2) Disassembly
a) "Remove the control value bypass tube from the booster assembly".
This instruction is typical of the Ford Shop Manual, in that it's not as helpful as it could be. Anyway, you do this by loosening the nut that's holding the bypass tube from the control valve body. Once the nut is loosened, the bypass tube can be worked off. Be careful because brake fluid WILL leak out when you do this.




b) "Remove the control valve body, diaphragm spring, and the control valve piston and diaphragm assembly from the slave cylinder body".
This is pretty simple. Remove the bolts, and it just comes right off.















After the housing is off, the housing and spring looks like this:









And the control valve piston and diaphragm assembly looks like this:











Getting the diaphragm assembly was a bit troublesome. There's a lock bushing of some kind, and I broke the bushing while taking it off. It appears to be part of the Rebuild kit in the Casco catalog, but not sold separately. I'll see how many of the parts in this kit need to be replaced, and see if I can get it separately if I need to.
Once I got the diaphragm off, it looked like this:





"Mark both bodies of the booster chamber and the flanges of the control valve and the slave cylinder so they can be assembled in their original positions. Remove the clamp ring, the outer section of the booster chamber, and the diaphragm and the pressure plate assembly with the return spring".
I didn't mark the bodies of the booster chamber, because there are plenty of ways to identify the correct orientation, and I took a picture.
You don't need to completely remove the clamp ring, just push it down over the inner section of the power chamber, so the outer section can be taken off. Again, be aware that fluid is likely to leak out.
Removing the diaphragm and pressure plate with the return spring was easy. Just rotate it counter clockwise, and it comes off easily.
Here's what it looked like as it was being removed:














Next instruction:
"Remove the push rod bushing and the inner section of the power chamber from the slave cylinder"
This part caused me a problem.

The bolt-head of the bushing is at least 1 1/2 inches. My largest wrench is 1 1/4 inches. I have some channel locks that can get that big, but channel locks are sub-optimal when removing a bolt.
Also, in the middle of the bolt, you'll notice a snap ring. Don't try to remove the snap ring without snap ring pliers. It's trivial with the pliers, and likely to break the ring if you don't use them. Once the snap ring was removed, there was a washer and a seal that came out easily.



Since I could not get the bushing out of the booster body and the slave cylinder body, and it was getting late, I stopped here for the night. I placed all of the parts in tupperware containers so they don't get lost or confused. I've applied some bolt loosener to the bushing, and hopefully it will be loose enough to get off with a 1 1/2 inch wrench later.