I recently finished replacing the worn rear disk brake pads on our 2003 E450 chassis and thought that other DIY folks would be interested in the problems I encountered and the tricks I learned.
I have been doing brake jobs on my cars since the 60's and the change from drum brakes to disk brakes has made replacing the friction material, aka brake pads, so much easier than replacing brake shoes on the old drum style brakes. I figured that the brakes on the E450 were just larger, heavier versions of what I had seen on cars. While this is true, there are differences that made the job more difficult.
The first problem occurred after I had jacked up one side of the rear axle and removed the lug nuts. I discovered that the wheels wouldn't come off. The inside diameter of the wheel rim is a snug fit over the axle hub and rust that had formed in the tiny gap prevented the rim from moving. Application of Liquid Wrench, prying, hammering, etc. did nothing to break the rusty bond. After a half hour of struggle, I recalled reading about a trick to break rusted rims loose. I put the lug nuts back on finger tight, dropped the MH off the jack and drove a short way down the driveway. A sharp application of the brakes resulted in the wonderful clunk sound of the rim breaking loose from the axle hub. This trick works because the holes in the wheel rims are over sized for the lug bolts, so loose lug nuts combined with sharp braking causes the rims to move slightly against the hub.
Picture of oversize lug bolt holes and tight fit of rim on hub
After jacking the wheels back off the ground, I was able to wiggle the outer rim and after about 10 minutes of effort finally got it off.
Picture showing rust on hub before removing inner dual. The inner dual also required lots of wiggling to get it off the hub.
I had chocked both front tires as well as the duals on the other side before jacking, but I don't trust jacks. So I used the wood ramps that level the MH when it's parked in the driveway to catch the axle hub if the jack should fail or the MH fall off the jack.
The next problem was getting the caliper off. All of the cars I had worked on had caliper bolts to hold the caliper in place. The E450 rear brakes have caliper pins, which must be driven out of slots in order to remove the caliper.
Outer end of upper caliper pin circled in red.
There are raised bumps on the ends of the caliper pins to prevent the pins from working themselves out when going down the road. The service info I had downloaded from Ford said that there is a special tool to squeeze the end of the pin so that it can be driven out. The local Ford dealer didn't carry special tools, so I came up with another way to squeeze the end of the pin. In the picture below, the two flat blade screw drivers tapped in with the hammer act as wedges to squeeze the end of the pin, allowing the raised bumps to clear the edge of the slot.
A 3/8" ratchet extension was the perfect size to drive the pin out with some hammer taps.
Close view of end of pin with raised bump circled. The bump is shaped with a slope on the outer end so the pin can be driven into the groove easily when assembling the caliper. The sharp edge on the inside prevents the pin from sliding out. The pins are constructed as `a sandwich consisting of shallow V's of stainless steel with rubber bonded between.
The outer brake pad is attached to the caliper. This made it necessary to do some hammering and prying to get the caliper with pad off past the slightly thicker outer rim of the brake disk.
On the driver's side, the brake hose was long enough and had enough flex to allow the caliper to be removed from the disk. On the passenger side the hose was shorter and it was necessary to remove a support bracket where the hose was attached to the metal brake line.
Once the caliper was free, it was hung with wire to keep strain off the brake hose.
After removing the outer brake pad, a C clamp and a block of scrap wood pressed the two caliper pistons into the caliper.
A comparison of the old and new brake pads. The old pads had almost 81,000 miles of use and still had about 1/4" of friction material remaining. Might have been able to go another 20,000 miles.
Before installing the new brake pads, I cleaned the caliper pins and lightly sanded the caliper pin grooves and caliper surfaces that come in contact with the pads to remove rust. These surfaces were then given a thin coating of caliper grease, with care taken to keep the grease off the pad and disk friction surfaces.
Picture of the reassembled caliper.
Before installing the wheels onto the axle, I lightly sanded the rim/hub mating surface and applied a thin coat of caliper grease, in the hope that the wheels won't be rusted to the hubs the next time.
Inner wheel on greased axle hub.
Since I hadn't disconnected any brake lines in doing the job, there was no need to bleed the brakes. A few pumps of the brake pedal extended the caliper pistons against the new brake pads. A syringe removed the excess brake fluid that had been sent to the master cylinder earlier when the caliper pistons were compressed.
After finishing the other side I took the MH for a short drive. Brakes work fine, good for another 80,000 miles.
I have been doing brake jobs on my cars since the 60's and the change from drum brakes to disk brakes has made replacing the friction material, aka brake pads, so much easier than replacing brake shoes on the old drum style brakes. I figured that the brakes on the E450 were just larger, heavier versions of what I had seen on cars. While this is true, there are differences that made the job more difficult.
The first problem occurred after I had jacked up one side of the rear axle and removed the lug nuts. I discovered that the wheels wouldn't come off. The inside diameter of the wheel rim is a snug fit over the axle hub and rust that had formed in the tiny gap prevented the rim from moving. Application of Liquid Wrench, prying, hammering, etc. did nothing to break the rusty bond. After a half hour of struggle, I recalled reading about a trick to break rusted rims loose. I put the lug nuts back on finger tight, dropped the MH off the jack and drove a short way down the driveway. A sharp application of the brakes resulted in the wonderful clunk sound of the rim breaking loose from the axle hub. This trick works because the holes in the wheel rims are over sized for the lug bolts, so loose lug nuts combined with sharp braking causes the rims to move slightly against the hub.
Picture of oversize lug bolt holes and tight fit of rim on hub
After jacking the wheels back off the ground, I was able to wiggle the outer rim and after about 10 minutes of effort finally got it off.
Picture showing rust on hub before removing inner dual. The inner dual also required lots of wiggling to get it off the hub.
I had chocked both front tires as well as the duals on the other side before jacking, but I don't trust jacks. So I used the wood ramps that level the MH when it's parked in the driveway to catch the axle hub if the jack should fail or the MH fall off the jack.
The next problem was getting the caliper off. All of the cars I had worked on had caliper bolts to hold the caliper in place. The E450 rear brakes have caliper pins, which must be driven out of slots in order to remove the caliper.
Outer end of upper caliper pin circled in red.
There are raised bumps on the ends of the caliper pins to prevent the pins from working themselves out when going down the road. The service info I had downloaded from Ford said that there is a special tool to squeeze the end of the pin so that it can be driven out. The local Ford dealer didn't carry special tools, so I came up with another way to squeeze the end of the pin. In the picture below, the two flat blade screw drivers tapped in with the hammer act as wedges to squeeze the end of the pin, allowing the raised bumps to clear the edge of the slot.
A 3/8" ratchet extension was the perfect size to drive the pin out with some hammer taps.
Close view of end of pin with raised bump circled. The bump is shaped with a slope on the outer end so the pin can be driven into the groove easily when assembling the caliper. The sharp edge on the inside prevents the pin from sliding out. The pins are constructed as `a sandwich consisting of shallow V's of stainless steel with rubber bonded between.
The outer brake pad is attached to the caliper. This made it necessary to do some hammering and prying to get the caliper with pad off past the slightly thicker outer rim of the brake disk.
On the driver's side, the brake hose was long enough and had enough flex to allow the caliper to be removed from the disk. On the passenger side the hose was shorter and it was necessary to remove a support bracket where the hose was attached to the metal brake line.
Once the caliper was free, it was hung with wire to keep strain off the brake hose.
After removing the outer brake pad, a C clamp and a block of scrap wood pressed the two caliper pistons into the caliper.
A comparison of the old and new brake pads. The old pads had almost 81,000 miles of use and still had about 1/4" of friction material remaining. Might have been able to go another 20,000 miles.
Before installing the new brake pads, I cleaned the caliper pins and lightly sanded the caliper pin grooves and caliper surfaces that come in contact with the pads to remove rust. These surfaces were then given a thin coating of caliper grease, with care taken to keep the grease off the pad and disk friction surfaces.
Picture of the reassembled caliper.
Before installing the wheels onto the axle, I lightly sanded the rim/hub mating surface and applied a thin coat of caliper grease, in the hope that the wheels won't be rusted to the hubs the next time.
Inner wheel on greased axle hub.
Since I hadn't disconnected any brake lines in doing the job, there was no need to bleed the brakes. A few pumps of the brake pedal extended the caliper pistons against the new brake pads. A syringe removed the excess brake fluid that had been sent to the master cylinder earlier when the caliper pistons were compressed.
After finishing the other side I took the MH for a short drive. Brakes work fine, good for another 80,000 miles.
Here Ya Go. Had to do a web search how to access photos on this new to me phone. 
The picture is right side up, meaning the Ford Logo is correctly upside down. Also, the shiny clip's round edge, prominent in the photo, is parallel to the pavement. This is the Driver Side. The Passenger side is also on the lower corner of the pad, making it the Leading Edge as described by Charles above.
Rear Hoses don't take the abuse the front ones do, but it could still be a good idea to replace them.
Two things about bleeding the brakes. One is Captain Obvious: The calipers have to be mounted with the bleeder at the top. Ford has reduced the number of late model front brake caliper part numbers to one, by putting a bleeder at both ends. Right and left interchangeable. I don't know if that can be done on rears or if they did.
The other: Don't let the Master Cylinder go DRY. If you do, the ABS Module can get air bound and you'll need a high line OBD scanner to allow bleeding it. I tried to fill the calipers with new fluid. Then I removed as much old fluid from the master with a turkey baster. Filled with fresh fluid and bled/filled, bled/filled till it was clear and bubble free.
The picture is right side up, meaning the Ford Logo is correctly upside down. Also, the shiny clip's round edge, prominent in the photo, is parallel to the pavement. This is the Driver Side. The Passenger side is also on the lower corner of the pad, making it the Leading Edge as described by Charles above.Rear Hoses don't take the abuse the front ones do, but it could still be a good idea to replace them.
Two things about bleeding the brakes. One is Captain Obvious: The calipers have to be mounted with the bleeder at the top. Ford has reduced the number of late model front brake caliper part numbers to one, by putting a bleeder at both ends. Right and left interchangeable. I don't know if that can be done on rears or if they did.
The other: Don't let the Master Cylinder go DRY. If you do, the ABS Module can get air bound and you'll need a high line OBD scanner to allow bleeding it. I tried to fill the calipers with new fluid. Then I removed as much old fluid from the master with a turkey baster. Filled with fresh fluid and bled/filled, bled/filled till it was clear and bubble free.
You're right Charles. Since the calipers are behind the axle, and the pads stand vertically, the clips go in a notch at the bottom of the caliper. The clips and the guide pins are in a pic I posted awhile ago, a page or two back.
I logged back in because I wanted to mention that those guide pins can be installed in the same two ways most things can: Right and Wrong. Right means that the little nubbins on the pins engage the Caliper Bracket. It's possible to install them in a way that the nubbins don't keep the pins from sliding out of place. That, and be sure to use a quality brake lube/anti seize/anti rattle like Permatex high temp for ceramic, purple label.
I logged back in because I wanted to mention that those guide pins can be installed in the same two ways most things can: Right and Wrong. Right means that the little nubbins on the pins engage the Caliper Bracket. It's possible to install them in a way that the nubbins don't keep the pins from sliding out of place. That, and be sure to use a quality brake lube/anti seize/anti rattle like Permatex high temp for ceramic, purple label.
A recent project reminded me of this excellent thread. Arrived at the campground with a hot right rear brake. It'd happened before, and I dismantled both rear brakes, cleaned and lubricated with this Permatex 24125 Ceramic Lube 
I really recommend the stuff. Buy a jar on Amazon Prime and save nearly half the auto supply price... Anyhow, hot again on another trip. This time I went with reman calipers, which come with a new
hardware kit, these pins, clips, and copper washers for the brake line
When we had the 1983 E350 chassis that used those slide pins, I found I could tap at about 45* with a drift pin right at those retaining bumps and they'd retreat into the bracket. Then I could drive them straight ahead like CD showed with the 3/8" extension. I couldn't work the bumps that way on the E450 rear calipers so I used CD's two-screw-driver approach. If I were going to do a lot of these I'd grind a pair of cheap HF screwdrivers to a chisel edge to help get them in place.
I'm adding this to provide a few "assembly tips" for those slide pins.
1. Of course, first lube the sliding surfaces and pins with that 24125. The auto supply stores sell little tear-off packages of "ceramic" lube, usually at the register. They're parked "enough for one axle" but on E450 it's more like "one brake" so get two.
2. If you forgot how the pin goes in, just remember that the BUMPS engage the Bracket, not the Caliper.
3. Parts must align perfectly. By that I mean the matching grooves the Pins go into.
4. Do the Lower Pin first, keeping the Upper from falling out by slipping the Drift Pin you used to drive the Pins out into the grooves temporarily.
5. Clamp a little 4" ViseGrip to the Pin to compress the end of the Pin where it enters the Groove! The tool will get in the way and it'll fall off as soon as you tap on the Pin, but all you need is help getting that first 1/8" - 1/4" into the Groove.
6. NOW tap the Pin partway in and repeat for the Upper.
7. Tap Pins till you have to stop with the Hammer and use that Drift to drive them down till the Bumps are against the Bracket. You'll hear and feel the difference. Check with your fingernail and you'll be able to tell the Bump is against the Bracket.
Above Steps took way longer to Write than to DO, and they took all the cuss-work out of the pins. With C-D's Two-Screw-Driver removal and the Vise-Grip-Install Pinch, those Pins aren't all that bad.
EDIT: And YES, the Rear Brake components like Pads and Caliper, are readily available. Autozone in Panama City FL (decent town but not a metropolis) had them in stock. Easy parts availability, even away from home, is a major Class C advantage.
I really recommend the stuff. Buy a jar on Amazon Prime and save nearly half the auto supply price... Anyhow, hot again on another trip. This time I went with reman calipers, which come with a new
hardware kit, these pins, clips, and copper washers for the brake line
When we had the 1983 E350 chassis that used those slide pins, I found I could tap at about 45* with a drift pin right at those retaining bumps and they'd retreat into the bracket. Then I could drive them straight ahead like CD showed with the 3/8" extension. I couldn't work the bumps that way on the E450 rear calipers so I used CD's two-screw-driver approach. If I were going to do a lot of these I'd grind a pair of cheap HF screwdrivers to a chisel edge to help get them in place.
I'm adding this to provide a few "assembly tips" for those slide pins.
1. Of course, first lube the sliding surfaces and pins with that 24125. The auto supply stores sell little tear-off packages of "ceramic" lube, usually at the register. They're parked "enough for one axle" but on E450 it's more like "one brake" so get two.
2. If you forgot how the pin goes in, just remember that the BUMPS engage the Bracket, not the Caliper.
3. Parts must align perfectly. By that I mean the matching grooves the Pins go into.
4. Do the Lower Pin first, keeping the Upper from falling out by slipping the Drift Pin you used to drive the Pins out into the grooves temporarily.
5. Clamp a little 4" ViseGrip to the Pin to compress the end of the Pin where it enters the Groove! The tool will get in the way and it'll fall off as soon as you tap on the Pin, but all you need is help getting that first 1/8" - 1/4" into the Groove.
6. NOW tap the Pin partway in and repeat for the Upper.
7. Tap Pins till you have to stop with the Hammer and use that Drift to drive them down till the Bumps are against the Bracket. You'll hear and feel the difference. Check with your fingernail and you'll be able to tell the Bump is against the Bracket.
Above Steps took way longer to Write than to DO, and they took all the cuss-work out of the pins. With C-D's Two-Screw-Driver removal and the Vise-Grip-Install Pinch, those Pins aren't all that bad.
EDIT: And YES, the Rear Brake components like Pads and Caliper, are readily available. Autozone in Panama City FL (decent town but not a metropolis) had them in stock. Easy parts availability, even away from home, is a major Class C advantage.
