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Does anyone know how much force is applied to the parking brake cable when the pedal is fully depressed? I have been through several pedal assemblies (including one new one), all of which have failed. The pedal assembly is discontinued by Ford so I am now trying to create my own way of activating the parking brake.
If you find that you have to step on the parking brake like an elephant just to get it to hold, perhaps the issue does not lie in the pedal assembly, but rather other issues need to be addressed? Brake cables free? Shoe assemblies inside the hub of the rear disc clean, dry, no axle lube leaking out on them, making them all slick and not properly engaging?
My 2002 Silverado had the same issue. Wouldn't hold, even on a 1% grade. Turns out the axle seal was just dripping enough to lube the brake shoes, but not enough to show a leak on a general inspection. Had to redo the entire rear bearing/axle seal assembly. Now I can push it down with two fingers and it will hold tight.
I should have included a little more info, the cables and shoe assemblies are fine (I replaced the axle seals, all cables, rotors, shoes and levers), it's the pedal assembly that has caused the issue. The retaining springs (the ones that go around the drum) broke in the first 3 used pedal assemblies so I bought a brand new OEM assembly which worked great for a while and then started randomly releasing. Sometimes a few seconds after application, sometimes minutes later. I can't trust it to hold, when when it does, it holds the truck fine.
These pictures show the spring on the drum that I mentioned above
Nothing like crappy engineering to make you
Other than getting a good assembly and, with a little study of the mechanism, and then perhaps welding in some "reinforcements" to the structure, I'll be interested in knowing how this goes. I'm still on the factory original foot pedal and it's working just fine. Stick shift truck here, so no just sticking it in park if I need to sit for a bit. Parking brake HAS to work for me.
Years ago I was very unimpressed with the performance from my parking brake. The lack of holding power from the parking brake was even worse as like you, I have a ZF6 transmission.
I took several steps to enhance the performance and holding power of the parking brake and to this day it holds the truck and 5th wheel quite well, even on a slight slope/hill.
I have not installed the textured rear rotors, but that will be my next step if the brakes start to give out again or I need new service brakes in the rear.
As for the pedal mechanism itself, I replaced that, along with the front and intermediate cable. As well as the parking brake shoes and associated hardware. Much like a lot of what it sounds like you replaced as well. When adjusting the parking brakes, I made it so that the pedal was not tightening about 1/2 way down to the floor. I made it so that the pedal was starting to tighten (resist force) about 1/4 the way down to the floor. This way, I had much more clamping force travel in the pedal.
I think I got the technique from AKCooper9, but cannot remember for sure since I have slept since then and do a memory dump each night.
Thanks for the responses. Good info there. Unfortunately, the pedal assembly is obsolete. I just called the Ford dealer and they said it is obsolete and no longer available. Auto parts stores tell me it is a dealer only part, no aftermarket availability.
So I am trying to design a system that will apply the correct amount of force to the cable under the cab, which will eliminate the pedal assembly.
The pedal assembly housing seems fine, it's just the drum retainers that seem to fail.
When I identified my pedal assembly had failed, I looked into repairing it. Turned out I was in over my head regarding a repair and purchased a genuine part off Amazon.
I see that it is unavailable now, as you have mentioned. With a search for F87Z-2780-AA brings up only one remaining part. I am not 100% sure this is the entire pedal assembly based on the crappy image and the country of origin is listed as China.
Sous, I'm always impressed with your willingness to help others! Your responses are frequently in depth and detailed.
I do find it interesting that you included links for F87Z-2780-AA. The dealer told me the part number for my truck is F81Z-2780-AA, the only difference being the third character. I'm wondering if the F87Z part is the replacement for the discontinued one. I did ask the dealer if there was any other part that superceded the discontinued one and he said no. But I didn't get the impression that he was really invested in his job... He told me to try Advance auto parts
Which brings up PriusLover's question about whether a newer one could be retrofitted. I will have to look into that, thanks for the idea!
I too find the lack of holding power of our parking brakes an annoyance. It has gotten to the point where I am thinking of replacing the brake shoes with knurled metal plates that bite into the brake drum instead.
I too find the lack of holding power of our parking brakes an annoyance. It has gotten to the point where I am thinking of replacing the brake shoes with knurled metal plates that bite into the brake drum instead.
Or the other thought that came to mind is modifying one of those truck driveline parking brake assemblies that are mounted on the tailshaft. That sounds like a lot of work for a one-off job, however.
Or the other thought that came to mind is modifying one of those truck driveline parking brake assemblies that are mounted on the tailshaft. That sounds like a lot of work for a one-off job, however.
The problem with that is if one wheel is on a low traction surface like ice and the truck is parked on a steep enough slope, that truck is still going to move because of the differential. Limited slip/TrueTrac notwithstanding.
The problem with that is if one wheel is on a low traction surface like ice and the truck is parked on a steep enough slope, that truck is still going to move because of the differential. Limited slip/TrueTrac notwithstanding.
Well, yeah, but now we're splitting hairs. If conditions are that sketchy, don't park on a hill!!
The parking brakes on these pickups is just woefully inadequate for the load placed on it. I put a good used one on a gal's pickup a couple months ago....about a year after a new one had been installed. The lady STANDS on this thing and it won't hold on a hill....even with correct adjustment, good shoes and decent drums.
