I thought I would offer a few words for reference on my struggle last night with the parking brake release in my '87 CV.
After replacing the release handle/rod assembly (snapped by the connection to the pedal assembly when I tried the parking brake when looking at the car), I realized that the release was not returning fully. This prevented the parking brake from holding when the pedal was depressed - it would just come back off when pressure was relieved. I got around this temporarily by reaching above the pedal and pushing the release bracket forward by hand at the point where the release rod attaches with the pin and clip. It seemed to have abnormally high resistance to returning fully, even though the return spring still seemed fresh enough. Graphite lube at the release bracket pivot did not help the situation. Last night I dropped the underdash cover and realized that when the brake release lever was pulled, the actuator rod to the automatic vacuum release was rotating clockwise (facing forwards) and binding up on the vacuum actuator housing.
After some tinkering, I was able to make the brake release operate reliably by putting a slight bend on the wing of the release bracket where the vacuum actuator rod is hooked. This limits the rotation of the actuator rod so that it doesn't change its position and bind up on the vacuum actuator housing. For good measure I also sprayed a bit of silicone spray on the diaphragm of the vacuum actuator to keep it fresh, since they are unobtanium in stock form.
Unfortunately I didn't have a camera handy last night, but looking at the parking brake assembly, it is pretty straight-forward. Why Ford didn't use the same linkage for the vacuum release as the release handle rod (pin/clip) is beyond me. That offset tab style is just prone to play and binding.
I was planning on locating the underdash wiring for my Tripminder installation, but seeing as it was almost 11pm by the time I solved the brake release issue and the shop is 25min from home, I didn't feel so inclined at that point!
After replacing the release handle/rod assembly (snapped by the connection to the pedal assembly when I tried the parking brake when looking at the car), I realized that the release was not returning fully. This prevented the parking brake from holding when the pedal was depressed - it would just come back off when pressure was relieved. I got around this temporarily by reaching above the pedal and pushing the release bracket forward by hand at the point where the release rod attaches with the pin and clip. It seemed to have abnormally high resistance to returning fully, even though the return spring still seemed fresh enough. Graphite lube at the release bracket pivot did not help the situation. Last night I dropped the underdash cover and realized that when the brake release lever was pulled, the actuator rod to the automatic vacuum release was rotating clockwise (facing forwards) and binding up on the vacuum actuator housing.
After some tinkering, I was able to make the brake release operate reliably by putting a slight bend on the wing of the release bracket where the vacuum actuator rod is hooked. This limits the rotation of the actuator rod so that it doesn't change its position and bind up on the vacuum actuator housing. For good measure I also sprayed a bit of silicone spray on the diaphragm of the vacuum actuator to keep it fresh, since they are unobtanium in stock form.
Unfortunately I didn't have a camera handy last night, but looking at the parking brake assembly, it is pretty straight-forward. Why Ford didn't use the same linkage for the vacuum release as the release handle rod (pin/clip) is beyond me. That offset tab style is just prone to play and binding.
I was planning on locating the underdash wiring for my Tripminder installation, but seeing as it was almost 11pm by the time I solved the brake release issue and the shop is 25min from home, I didn't feel so inclined at that point!
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