Slack Adjuster

[buswarrior]

Is the adjusting bolt really rounded off below the locking ring?

That one looks like it might be supposed to be round on the end of the bolt.

As long as the adjuster bolt is not ruined below the ring, there is less work in trying to get the adjuster internals loosened up via the advice earlier in the thread, than replacing it.

After using the thinner fluid, be sure to follow with lots of grease.

happy coaching!
buswarrior

[bevans6]

Reading the original post again (always a good idea to read what the problem actually is before offering advice, saves on later edits to avoid looking foolish on my part I find...)  "it (the adjuster) will only turn one turn each way and then locks up."  So the locking ring moves out of the way and unlocks, a wrench is on the bolt head, and it turns two full turns, one way then the other.  The inside of that bolt is a worm gear, the other half of the worm gear is the outside part of the splined bit the S-cam slides into and that big ring is what is most likely seized.  Copious amounts of solvent (I like to use Marvel Mystery Oil for some reason) pumped through along with judicious wrenching on the adjuster may indeed free up the ring/worm gear/splined thingy.  Spraying brake clean spray all around the ring where the S-cam protrudes through the slack adjuster would also be indicated.  There's nothing else in there with a manual slack adjuster, just the two parts...

Brian

[Bob Belter]

Ahoy, Don & Cary,
I've just been there with the brakes on my -01 Eagle drive axle.  I did have to remove the wheels and drums, in order to slide the 'S' cams out so that the slack adjusters could be removed.  My -01 looks just like your pix, except that mine was very greasy.  I could not entirely remove the 'S' cams without removing the hubs. Mine had a snap ring inboard of the slack adjuster, and a second snap ring out by the outboard bearing.   My bearings were OK, so I didn't bother to replace them.

My slack adjusters were 'difficult  //  draggy'.  Lottsa grease and solvent, and an air wrench to run them back and forth did the job.  I tried to install proper new ones, but could not get the splines to mate.  Must have been a tolerance problem.

Good luck   /s/    Bob

[bobofthenorth]

Careful use of heat in conjunction with your favorite brand of weasel piss may help free up the mechanism.  But as Clifford has already pointed out there may be so much wear in the bushings as to render all that work moot - if the bushings are that bad though you should be able to see/feel the movement when you pull on the slacks. 

[Cary and Don]

We finally got the adjusting screw soaked and turning.  The part of the nut in the sleeve part is ok.  It just looks like they twisted the top part of the bolt off.  We finally could turn it and see the shoes move. The shoe closes down so the paper will not slide out with application.  It took three complete turns to get the shoes tight and then a half turn off. We need to do a test drive and see what happens.

Don and Cary
1973 05 Eagle
GM 4107
Neoplan AN340

[buswarrior]

measure the stroke now that you have functionality.

Worn bushings will allow excessive stroke, even with the linings snugged up.

If you can get an inch or so, and the linings are indeed clear when released, you have no worries in the mechanical department.

happy coaching!
buswarrior

[luvrbus]

Don, the reason your parking brakes take 5 or so seconds to release or apply is the 05 does not have a Bendix QR valve install one it's not that big of a job then it will be instant

good luck

[Cary and Don]

Luvrbus,

Look at the pics on the Eagle sight.  It has a quick release on the park brake, which we have changed out.  Maybe it isn't in the right place.  The air exhausts in a blast and then kind of trickles at the end.  It seems like the slack adjusters move slow after the air exhausts.  The application brake is plumbed into the park brake through a two way check valve.  We figured this was for anti compounding.  This kind of makes setting the park brake on a slope a little difficult.

Don and Cary
1973 05 Eagle
GM 4107
Neoplan AN340

[uncle ned]

About good busnuts

At the Palmetto Cove rally  my good friend,Dave Bullock came up with a box. He said you need these.  It was a box of 4 brand new slack adjusters for a 4104.

Sure do miss him. He was a walking book of knowledge on gm buses.

uncle ned