Trans Mounted Parking Brake (C20)

[cshanek]

I have a 1964 C20 pickup truck with an OEM transmission-mounted parking brake. Lately, I've been having trouble getting it to hold the truck securely on uneven surfaces. I've adjusted the adjustment screw a few times, which temporarily improves the situation, but it eventually goes back to not working effectively.

I'm looking for advice on what to check and how to fix this issue. Specifically:

1. What kind of material is used to apply friction (the white band in the picture)?
2. I read through this thread which indicated I could find a material that would work, but I am not 100% sure what material I am looking for. Can anyone clarify?
3. Does anyone know where I can buy replacement parts for this type of parking brake (e.g., springs, bolts, boot)? I can't seem to find much.
4. The vertical bolt to the right of the lower spring (with 2 nuts on top) is just kind of free-floating/rattling around in place. Any thoughts on this?
5. Is there an easy way to run lines to convert this band brake to use my rear drums? If so, what are the benefits and drawbacks of doing so?
6. I haven't had any luck even finding a parts diagram for this setup really

Any tips, advice, or step-by-step instructions would be greatly appreciated.

Thanks in advance for your help!