Issue with new drums

[sparky72]

Here's the best thread I've found on how the wiring for the switch and light works: https://fordification.com/forum/viewtopic.php?t=68376

[bobslaven]

Great point out, I didn't find that one in my searches.

I'll try to score a new 2 pin harness in the future. In the meantime, the bulb is performing its duty.

Next step is to rebuild the valve, get out the plastic debris and such.

Thank you, sir.

[bobslaven]

FORDification Folks,
Trying to get that piston out of the brake pressure differential valve wasn't easy...and mine is pretty much like new.
I pried gently with a small screw driver through the switch hole to work it close enough to the exit to grab the piston with a small set of needle nose pliers, but they kept slipping off when I pulled. Then I grabbed the piston again with the pliers and locked 'em in good and tight with a channel lock. Pulled right out!
I was kind of looking forward to the grease gun technique, but not towards finding good hardware to plug those back side ports with - or cleaning out the grease.
Hopefully helpful to somebody in the future.

Billy Bob

[sparky72]

Getting that pin out without marring up the pin or the housing can be a real bear, but once it's out the rest of the rebuild is gravy.

[bobslaven]

Brake pressure differential valve rebuild complete. Everything hooked back up, MC bled, brake bled, warning lamp out (and the switch works).

Still need to check if those o-rings are leaking in the valve.

Brakes works about like they did a week ago. Seem totally functional, but don't engage until the pedal's about 1/3 or the way down. Gotta take 1972hiboy's advice and test it out on a nice drive in traffic, see what happens. I'm pretty sure I need to adjust them out quite a few clicks, though.

Bad news is I've located a fitting leak in the brake line at the front driver's side. Pretty much only during application. Looks like I'm going to need to take that off and try to see why it's leaking. May get to learn how to flare tubing..

[1972hiboy]

The good news is that front drivers steel line is the shortest. Double flaring tubing isn't really that bad but the steps and directions provided by the flaring tool manufacturer must be followed to a T to work right. Also there are alot of options now for flaring tools.

Not surprised about the pedal going 1/3 way. Most of your store bought brake shoes don't match the curvature of brake drums out of the box. At a shop I used to work at years ago that specialized in vintage car maintenance we had an old brake shoe re-archer. We ground the high spots off the brake shoes until the entire shoe made contact with the drum then assemble on vehicle. Of course in CA we aren't supposed to own that stuff anymore or let alone use it. So what is most likely happening is your high spots on the shoes are making contact to the drum first but perhaps not all of the brake shoe is making contact. You will need to drive and wear those high spots down and keep adjusting until they break in. Also in adjusting, you want more than just the sandpaper sound, you want enough adjustment that the wheel has some drag to it.

[bobslaven]

Super great info, makes total sense and makes me feel better about my work. Sounds like I'm on the right track with friction and adjustment. I'll consider this problem solved unless 100 miles from now the pedal travel hasn't changed. Thank you so much for helping me through this!

[beejaytx225]

I'm in the same boat as you here. Lots of good info on this thread. I'll stay tuned for more