1940 Brake Bleeding

[bobH]

Originally Posted by 19Fordy

Mike42:

Here is the correct order for bleeding drum brakes starting with the wheel farthest from the master cylinder and then bleeding each of the other wheels in decreasing distance order from the master cylinder.

1.Right Rear 2. Left Rear 3. Right Front 4. Left Front

Bleeding Process
Begin at the wheel furthest from the driver and proceed in order toward the driver. (Right rear, left rear, right front, left front.) While the actual sequence is not critical to the bleed performance it is easy to remember the sequence as the farthest to the closest. This will also allow the system to be bled in such a way as to minimize the amount of potential cross-contamination between the new and old fluid.

We would never be able to agree. Farthest, nearest, whatever, I've NEVER been able to understand what difference it makes. 'Course, I'm new to this game. I only have about 65 years into it so far. Referring to my post #33, and starting with a completely open, clean, 'no-fluid-in-it' system, and with all the bleeder screws OUT, here's all I did... Bled the M/C (It was fresh and empty, too.) 2. Gave couple pumps to m/c, and see where fluid comes out. It came out of RF. 3. Put bleeder back in RF, loose, gave it one more pump, close RF bleeder. (No helper, working alone.) 4. Repeat step 2. Fluid came out RR. 5. Repeat step 3. 6. Repeat step 2 & 3 (LR). 7. Repeat again (LF). 8. DONE. I've got a firm pedal. And, what the heck if I missed a little air. It's going to work it's way out, anyway.
'Course, I have other ways of doing it, too. When I'm working on modern cars, and simply flushing the system, I use a vacuum pump system, working through a glass jar. That way I'm able to see when the contaminated fluid ends, and fresh fluid starts. For this scenario, I finish with a couple of aggressive pumps on the pedal, in attempt to flush whatever wheel cylinder I'm working on.
And, for really difficult systems, and only once have I done this, I have pumped the fluid backwards. An aircraft mechanic taught me this, many years ago.
And, if I happen to have a helper, I've done the 'hold the pedal down, let me pop the bleeder, close it'.
Worse situation I've run into, is 'home-builts', where the fabricator routed a line from a high-mounted m/c, down to the frame, then, somewhere along the plumbing path, the line was routed higher (usually to go over something). This creates a place for air to collect, and a spongy pedal. Air won't work it's way out of one of these 'trapped' high spots. I have a friend with a Bonneville Studebaker, with the brakes plumbed this way. And, he is always fighting a spongy pedal. He can bleed, and bleed, and get a firm pedal one day. Next morning, it's spongy.
Obviously, lengthy, windy opinion.