Parking Brake Cable Replacement

Sorry – I didn't even know it was possible to replace the cable alone. No, I'm replacing the entire cable assembly, and failing miserably. Yes, the driver's torque box is the area that's giving me the problem, and that may be why this problem is uncommon.

Thinking I was clever, I actually fabricated a sheetmetal turnbuckle, connected the new cable to the old at the front before I removed it, and tried to use the old cable to guide the new one as I pulled the old cable out from the back, but they got badly hung up in the bid area trying to pull them through. After a lot of work, I finally pulled them out again from the front.

I just don't see any way to use a string or wire to lead the cable through the area I'm having trouble with. I just don't have adequate access.

I'm not looking at it right now, but is there any reason I can't just buy/fabricate retaining clips to fasten the cable along the inside of the frame rail and avoid this problem altogether, or would the force of using the parking brake be too much strain on the clips?