On a associated company yard were three older trucks at 500,000 and ready for trade sale or Auction, sat out the Entire Winter thinking MAY end up used as spares but now need GONE. First truck up, change Batteries as Failed to routinely start, got it running then LF Wheel would NOT roll, bumped it a few times in PD Lock and broke free, It left unscathed. Next TWO, Both could not be coaxed to move, Maxi Supplied Drive axles were LOCKED Down, ended up removing wheels and "Massaging" on Outer Brake pads to rotor to free it up as was RUST Bound in support and to rotor. Got the next two moving, One almost made to trade yard wheel smoldering as brakes got hot, towed in and then into shop for Air Disc OH, the other screeched so loud they had to rebuild brakes to get off the yard. Will Not ever sell me on Air Disc.
How many times have {I} written about the woes of air disc? What eight times. Those were crap 10 years ago & haven't changed, I like the fact everyone buying new trucks keeps buying with air disc. They get what they deserve, by not checking all the variables.
Will ALWAYS remind me of the Over Complicated, Too Tender Bendix WEDGE Brakes, and just as worthless over time even as Great for Auto adjusting New.
The real experience is when a complete set of drive axle air disc are replaced/rebuilt. Then the bad taste takes on a even richer flavor. Not the guy paying for it, he asked for that, the guy doing the work is the one who really feels it.
Is it possible to swap an axle over from disc to drum? I have never actually laid hands or eyes really on an air disc setup.
Axle bolt flange should be similar, however would require a lot of other changes as Hubs instead of Rotors inboard would have drums outboard, stud lengths, p/n interchanges. Do not know.
It would be less crap to install a complete used S-cam housing. Depending on drive axle center section.
OK, thank you for the info. I don't touch trucks unless it is engine work and that is only on older cats and cummins or the occasional dt466. I worked for a trucking company for about 6 months over 10 years ago and that was enough for me to realize I don't like the repeditivenes of trucks or fleet work. It was always brakes, grease, oil change and every once in a while throw in a clutch or a/c job. My adhd couldn't take it anymore and have been on equipment ever since.
Was "schooled" on wedge brakes at CF, entire fleet had them, power, trailers and dollies. May have been good concept when shiny new, warm, salt/rust free operation, but were a nightmare in harsh climate operation.
Got relatively good at Gas Axing the adjusters thru the tool holes, only way could retract shoes enough on some to clear the drums to remove hubs.
And the last place wedge brakes to be used was a dump truck/cement mixer.
Don’t I Know it!! All really not want to remember was reinstall as took out for angle of Wedge Actuator, all small parts got replaced, replace diaphragms, USE Supplied grease, always, ALWAYS, New Drums. Were LH and RH self adjusters. Worthless crap.
How many times did foundation S-cam/shoe/drum brakes have a redesign through the 80 years of production other than a brand type Eaton or Rockwell. Only minor changes to hardware, s-cams and finally extended wear. Since air disc came out the rotors and calipers have been superseded about 6 times already, which includes the spider mounts. What will be interesting is finding parts for 20 year old air disc that's been dropped from production for years.
Is there a way to back off on air disc? I've never worked on them but the T880 I run uses them. It constantly locks the steer axle while trying to slow maneuver like back through a doorway. Have to be quick on the R and N buttons or its very dangerous. Wouldn't be too bad with a proper transmission but I didn't pick thus turd.
The standard T bolt for holding off park side of air chamber. Backing caliper adjuster is under a rubber plug and takes a 8mm socket for Wabco or Bendix uses a adapter {star shaped} also under a rubber plug that uses a 10mm. But If locking up it has other issues. Moisture inside of calipers is death, sounds like a {not releasing issue}. I don't like air disc but when it's working brakes are smooth. Thing is if not turned the correct direction and it stops turning {STOP} trying to turn it immediately, the heads of adjusters will snap off rather easily. Once that happens it's acquire another caliper. The special tools to rebuild are expensive and it's a time consuming job. And if moisture has made it's way inside it's junk anyway. There is very limited factory rebuilt calipers on the market, it's mostly replace with new at the tune of $650 to $1,300 depending on brand. * To do a rotor change and wheel seal is roughly 2 hours a corner for a novice, fastest I ever changed out a corner was 1.3 hours--and that was bustin ***. If you throw in trying to rebuild calipers the time went to 4.5 to 5 for one corner. At shop rates of $175 hr my as well install new.
Ad from 40 years ago talking up KH design, it didn't last very long, nothing but issues. *
It sounds like everything else in today's day in age. Manufacture components that are too expensive and too labor intensive to repair so we just throw away and buy new. It is amazing the amount of trucks that come and go from some of the local landfills in a day
Years back trucks were built to be rebuilt--sometimes twice. Manufactures today, don't design for a truck running past 1 million miles, and that goes for all brands. The industry has geared itself to selling new trucks, with a parts line dwindling down in 10 years after it's birth. With constant upgrading in the electrical system--it's not profitable to keep manufacturing electrical parts when they know it's past it's prime and newness has worn completely away and it's not long before it ends up in a rendering plant. Eventually all the old repairable stuff will be gone and the only avenue left is to buy new. It's kind of a paradox--people keeping old engines/ trucks/tractors you name it they will try to keep it. But that new high powered diesel pickup, got's to have that, because it's pretty well used up by 400K. It's all about the use of plastics in manufacturing, the only thing that was plastic in 70's W900 was the headliner. It was also loud inside.
Same with all of the old off highway equipment. The really big cat stuff is made to be rebuilt over and over but most of it not. I look at 4wd ag tractors with weights added to them all of the time and think about our old steigers that never had a weight one. There was no plastic in those and you didn't need to buy extra and add weight because itbwas built into the base tractor. I remember as a little kid trying to open the hood one time and giving it all I had with no luck...hoods were made from several sheets of 1/4" plate bent and welded together. My little 60-70lb britches didn't stand a chance lol
That old KH style actually worked similar to S Cam shoe brakes, with calipers like the Medium Duty BENDIX Junk Juice Brakes. Was simple yet complicated. Main issue I saw of those was premature pads failures from corrosion effects on sliding components. Repair parts availability sucked.
I don't like pickups that have disc and drums together . The pickup I had and used the most had 4 wheel drums and it seemed to have the best brakes of any pickup I have drove I pulled a lot of trailers with it.