1980 F350 4X4 C6 Project

[Atlas75]

I also have a wheel/tire question.  Has anyone had clearance issues with 16” wheels and the front calipers?  I have heard that sometimes grinding on the calipers is required for clearance.

I currently have the 16.5” wheels mentioned earlier in this thread but I purchased a set of 16” and now I am looking for an appropriate tire size.  I like how the current tire fills out the wheel opening so I would like something similar and that should keep the speedometer pretty accurate.  I measured and they are roughly 31.75” in diameter and say 12-16.5 on the tire but no mention of diameter on the tire.  I was thinking 285/75/16 but am not sure.  What would y’all recommend?

[Gary Lewis]

I would pull a wheel and slip the new one on to see how it fits. Spin it to see if it hits the caliper.

As for the tires, I use Tire Rack’s info. Pull up a tire you are interested in and look at the specs. That will tell you the diameter as well as wheel width they should be used on.

On the splice connectors, I don’t think they should have a place on any vehicle. I solder my connections and use adhesive-lined heat shrink over the joint. And I don’t have connection problems, now or later.

As for the brakes, the calipers are supposed to slide to line up with the rotor. But the Bullnose ones don’t slide very well. My guess is that yours are frozen in place, causing it to wear the pads badly. And maybe cause them to grab.

But the rear brakes can also cause pulling. Had brake fluid gotten on the lining of the shoes?  That will certainly cause one to grab. Or maybe they aren’t adjusted evenly?

[Atlas75]

The shoes all looked dry when I reinstalled them.  I adjusted them by turning the adjustment wheel until the drum locked.  Then I backed it off about 10 to 12 clicks.  Not sure if that is right but that is what I did.

I watched a few videos on that style front brake and they seem to show a wire clip on the back of the caliper by the pads.  Mine doesn’t have that on either side.  What is the purpose of the clip and what might happen with it missing?  I also noticed I could barely turn the front rotor by hand.  I had to get a screwdriver and pry between the hub and the wheel studs.  It certainly seems tighter than it should be.

[ArdWrknTrk]

The Z-clip across the back of the pads keeps them from rattling in the caliper.
I'm not sure if they were incorporated into 1980 model year calipers.

Lubing the caliper sliders could help equal the wear between active and passive pads in the caliper.
It might also keep the brakes from dragging so much.

The wheel studs mount through the hub and rotor.
I don't really understand how that would free up the wheel.
Can you explain what this does to free it up?

[Atlas75]

It doesn’t free it up.  It just gives me more leverage to turn the rotor.

[ArdWrknTrk]

Oh!     That can't be good.  😳
Yes, that's much tighter than it should be.

So you haven't removed the caliper to determine whether it is the brakes or the bearing that is dragging?

[Atlas75]

I think it’s the brakes because I can wiggle the outside pad but the inside pad is tight.  I can’t get it to move even a little bit.

I never thought about it being a bearing issue.  I hope thats not it.  Hopefully I can get the caliper off in the next few days and confirm.

[ArdWrknTrk]

It appears the caliper and bracket are really dusty or have a light coat of mud.
I would probably get new hardware kits for both sides (with retainer bolts, and Z-clips if applicable)

Spend some time with an old toothbrush getting everything clean, and deburr if necessary.
Lube the slider and pin surfaces so you know the caliper itself isn't binding.

[Atlas75]

I went out to remove the caliper tonight.  I was encouraged when the bolt came out relatively easily.  And that is where the “easy” ended.  I could not get that key/spring to budge.  I noticed the tire side of the key was peened over a bit so I tried driving it out from the backside with a hammer and punch.  No dice.  Should the key go in/out of either side?

Then I tried a bigger hammer and punch on the caliper to see if I could get it to slide side to side.  No dice!  Is there something I’m missing here or is this thing just bound up with dirt and rust?  Oh, I also sprayed down the key ways with PB Blaster.

[Gary Lewis]

The bolt is the "key retaining screw"?  Here's the procedure from the factory shop manual:

[Atlas75]

So it should just tap out.  I tried it again tonight and it still would not budge.  I guess I’ll keep spraying it and hammering on it until it lets loose.

[Atlas75]

FINALLY!  After a week of spraying and hammering, the key came out of the passenger side caliper.  Yesterday the caliper started to slide just a little but so this morning I focused on that and got a fair amount of movement by compressing the pistons and hammering the caliper back and forth.  The key still needed a lot of work and took about two hours to get it out.  It was just filled with rust and dirt.  I think I’m going to get new hardware and pads and reuse the caliper.  The pistons did compress so I am hopeful it will work ok.

[Gary Lewis]

Congrat's!!!  Glad you got it out.

But you can rebuild the caliper.  They sell pistons and seals, which is all that needs to be replaced.  I did it for Big Blue and they work great.

[Atlas75]

I’ll have to look for a video on how to do that.  I searched Rock Auto and found the caliper rebuild kits but they are out of stock on the kits with the piston seals.  Anywhere else sell a good kit?

[Gary Lewis]

I didn't create a video of refurbishing the calipers because it was pretty straight forward.  But this thread shows the results and discusses a couple of things about doing it.

And this post details what I ordered.  

[Atlas75]

I was able to remove the caliper from the drivers side today.  After the fight I had with the passenger side I fully expected more of the same but it was not nearly as bad.  I did find something strange though.  While the key was still a pain to remove, the caliper itself was not tight in the knuckle like the passenger side was.  In fact it seemed more loose than it should be.  I could move the caliper up and down about 3/16 of an inch in the knuckle.  Does this seem normal?  I took a few photos.

[Gary Lewis]

That’s not normal. It should be a pretty close fit or it will rattle.

While you can’t swap the calipers and use them that way you should be able to swap to see if it is the caliper or the knuckle that is wrong.

[nic55kel]

I thought the spring was supposed to take up the free play.
How do the springs compare?
If the spring is okay then that amount of wear on either the caliper or the mount should be easily visible.

[nic55kel]

Here is a thread that may give you some useful information:

https://www.ford-trucks.com/forums/1498309-brake-caliper-falls-off-1981-f-250-dual-piston-caliper.html

[Gary Lewis]

Yes, the spring is supposed to take up the slack.  But I don't think there is supposed to be 3/16's of an inch slack.