failing brakes/ wet rear tire?

[Justshootme84]

Jumped in the 78 Bronco today and fired it up, haven't driven it since a run right before X-mas. I was having a problem with the brakes going out, and figured it may be a leaking rear wheel brake cylinder. When I came home the other night and shined the headlights on the Bronco, I could see a big wet streak down the inside of the right-rear tire. So today I pulled the tire off, and wrestled with the rear drum to pull it off. Had to adjust the shoes almost all the way in, since the drum is badly worn and has a big ridge cut into it. To my dismay, the brake cylinder is fine, and the axle seal is what's leaking. One of the shoes was soaked with gear oil...

Now the fun begins, since I have to pull the axle and take it to a shop to have the seal changed. It's pressed on, along with the bearing and retainer ring. Will need to rent a slide hammer to remove the old bearing race, too. I may even do a write-up on the bearing/ seal replacement, since I was planning to do one for the brake job. JSM84

 

[88horse]

well hold ur horses u dont need to take it to a shop there easy to replace what rearend do u have?

the same deal happend to mine the gear oil saturated the shoes and my front had to pick up the slack if u have the 8.8 there really easy take off the cover on the rear jack up the rearend of course rotate the tires til u see the bolt on the pin deal that holds the spider gears in place turn tires one more time get that pin out and then ull c a c clip in there kick u tire in towards the center and itll come out easy as far as the seal get some vise grips and crush the seal and pry it out get a chilton for er

Jumped in the 78 Bronco today and fired it up, haven't driven it since a run right before X-mas. I was having a problem with the brakes going out, and figured it may be a leaking rear wheel brake cylinder. When I came home the other night and shined the headlights on the Bronco, I could see a big wet streak down the inside of the right-rear tire. So today I pulled the tire off, and wrestled with the rear drum to pull it off. Had to adjust the shoes almost all the way in, since the drum is badly worn and has a big ridge cut into it. To my dismay, the brake cylinder is fine, and the axle seal is what's leaking. One of the shoes was soaked with gear oil...
Now the fun begins, since I have to pull the axle and take it to a shop to have the seal changed. It's pressed on, along with the bearing and retainer ring. Will need to rent a slide hammer to remove the old bearing race, too. I may even do a write-up on the bearing/ seal replacement, since I was planning to do one for the brake job. JSM84

 

[Justshootme84]

The 78 Bronco has a Ford 9" rear axle, with a Currie Nodular iron center-section, full spool and 4.88 gears. The 9" axles have the seal, bearing and retainer ring all pressed onto the axleshaft at once and in that order. So to change the seal, you have to break off the retainer ring and press off or cut off the old bearing. idid this r&r on my 79 F-150 a few months ago, and it's the same way with that Ford 9" axle. JSM84

 

[Krafty]

I had an 81 with the 9" and it had a clip that bolted on the outside of the axle shaft, all I had to do was take out the 4 bolts and pull the axle shaft and drum out and replace the seal then slide the shaft and drum back in and bolt it back on, I never had to get into the ***

 

[Broncobill78]

That's right, the 9" isn't a C-clip axle so the shafts can be removed without going into the differential. That piece with 4 bolts that you removed was the bearing retainer

 

[Justshootme84]

I did some work today, but in the process of taking pics and swatting mosquitoes I dropped the camera and it quit working...

Instead of doing a full write-up, I'm just going to post here what I'm doing. As mentioned before, the 78 Bronco has a Ford 9" rear axle. After placing jackstands under the axle and removing the tires/wheels, I had to turn the brake shoe adjusters several clicks to get the drums to pull off. The driver's- side is the seal that was leaking, and those shoes look fairly new. They had to have been replaced recently before I bought the Bronco. I left everything in place, so I would have a reference for the other side. The passenger-side brake shoes and springs look to be original - worn shoes, rusted and broken springs, leaking wheel cylinder. All that stuff basically fell off with a little help. The local NAPA charges $8.75 to turn one drum, so I 'm gonna get both of them done tomorrow. The rear disc swap looks like it will cost around $500-$600, so that's not gonna happen anytime soon...

To remove the axleshafts, there are 4 bolts holding the shaft and retaining plate to the axle housing end. The axle ****** has a hole in it to access each nut on these 4 bolts. Loosen one bolt, then rotate the axleshaft until the next one, and so on. The axleshaft SHOULD slide right out after removing these 4 bolts. On the pass. side, it did, and the bearing race stayed inside the axle tube. IT normally takes a slidehammer to remove the race, but I was able to get it out with a 2-jaw puller. The driver's-side was a bear, and would not come out easily. After pulling and pulling with all my might, it finally came out. The bearing race also came out, stuck onto the bearing. This often confuses folks when they pull the axleshaft and the race comes out with it.IT SHOULD NOT What normally happens is the bearing goes bad, freezes to the race, and it can damage the axle tube if the race is allowed to spin long enough. I'll be able to tell when I go to install the new race how tight it fits. IF it just pushes into the axle tube easily, the tube is worn. Crossing my fingers that it will fit OK.

Next step is to take the axleshafts to a shop and have them change out the old bearings and seals. On each shaft, next to the retaining plate is the seal, then the tapered roller bearing, then a retaining ring. It takes a 20+ton press to remove the old retaining ring and bearing (or a cutting torch), then press on the new seal, bearing and ret. ring. I have a seal & bearing driver set that I use to install the new bearing race. It needs to be hammered into the axle tube before re-installing the axleshaft with new parts. Tighten up the 4 bolts, and done.

The rest of the evening was spent pulling the 9" center housing or "chunk" to re-seal it. I noticed a leak on the bottom, where either the gasket or silicone had failed. Normally an easy task, but this one was very stubborn!!! I unbolted the driveshaft, then removed the 10 nuts holding the chunk in place. It took a good while to pull the chunk out of the axle housing. I finally wedged it out and onto the floor. It ain't light!!! There was no gasket, only a small bit of silicone left to scrape off. Instead of buying a new gasket ($7.00) I bought a $6 tube of PermateX Ultra Copper to use to seal the chunk to the housing. I laid a good 1/4" bead all around the opening for the chunk, then lifted it back in place. it went in alot easier than coming out. The previous owner used Amsoil synthetic ***** but I plan to run regular 80-90W gear oil with some Lucas oil.

Next update will be after I replace the brake shoes & hardware on the pass. side, and clean the gear oil off the shoes on the driver's side. JSM84

 

[Justshootme84]

Looks like the pass-side drum can be turned, as it's not too bad. But the drum from the driver's side is worn down at least 1/4", and the local NAPA refused to turn it since it would likely be out of spec. So now I have to look for another good, used rotor, as I'm not paying $54 for a new one. Anyone know if the rotor from a Ford 8.8" rearend would work? I have the 86 Bronco here, with the 8.8". JSM84

 

[Justshootme84]

I took one of the brake drums off the 88 Bronco 8.8" rear axle and had it turned. it fit right on the 78 Bronco 9" rear axle. It helps to hold the brake shoes on the backing plate while trying to insert the pins and springs, so I used an 11" belt to hold them up. Might be the old belt from the smog pump to alternator on the 84 Bronco? Anyhow, leaving one side intact while working on the other allowed me to put everything back in order. I wentr ahead and replaced the driver-side shoes that had gear oil all over them, since I needed to replace the wheel cylinder anyway. I adjusted the shoes so there was a slight resistance when turning the drum, and slapped the tires and rims back on. I put 3 quarts of 80W-90 gear oil plus 1/2 quart of lucas in the rear 9" but it's still low. Drove it around the yard today after bleeding the rear brakes, and backed up a few times to let the rears adjust themselves. All works fine, and the Bronco stops like it should now!!!. JSM84