m818 brake issues

[dezert ratt]

I pulled my truck in to the shop today to start working on the airpack rebuild, and check/ adjust all the brakes. I pulled the front tires off the truck, the pass front brakes are dragging so much, i can hardly spin with the wheel on the truck. Now i read up on the tm for adj. the brakes, and when i loosened up the 4 adj. on the pass front hub, the hub locked up completely. Here is where im baffled. I opened the bleeder for the wheel cyl, did not help. I messed with the adjusters, did not help. Now im wondering if the return spring is broken? How can i pull the hub/ drum off, with the brakes so tight? This is my 1st big truck, and its still new to me. Any and all help appreciated.

 

[dezert ratt]

Tomorow im gonna get at it again (when its daytime). I have a brand new 2000lb trans jack, im gonna modify to bolt the hubs on. It should replace soldier B as far as heavy lifting of the hubs on and off the spindles. Pics to come!

 

[dezert ratt]

 

[Hooty481]

just curious but did you happen to loosen one brake shoe while tightening the other shoe. it the only thing that i can think of that might have caused this to happen. remember one of the top adjustment bolt its right tighty lefty loosey and the other one is the opposite. hope this helps if not sorry for taking up the space

 

[dezert ratt]

I made sure to turn each bolt towards the center of the hub, away from the drum. I even tried tightening all 4, each in the tightening sequence. Its either gotta be a stuck wheel cylinder, or a broken spring.?

 

[Hooty481]

the stuck wheel cylinder may be a possibility but i think you could still spin the drum if the spring was broke. does it spin at all? does the other side still spin?

 

[dezert ratt]

The driverside spins free, the passenger side is completely locked up now. Before i loosened the adjusters it was just tight and dragging. Now i cant even spin it with a 4 foot breaker bar as leverage.

 

[rrrr]

You've locked it up with the adjusters. Look in the TM to see which way to turn them to loosen. You might also remove the brake line just in case there is some pressure on the brake cylinder assembly.

 

[Floridianson]

If I rember the back one is CCW and the front one is CW on the top adjusters.

 

[dezert ratt]

The inspection hole is at the 1 o clock position. When i turn the adjuster either way, the brake shoe does not move. There is no gap between the drum and shoe. Im positive i have turned the adjusters the right ways. Its daylight again, so im gonna get back at it.

 

[doghead]

You might(with some damage possible), remove the wheel cyl bolts and try twisting it out of it's mounting holes. That may allow the shoes to retract more.

You can cut the drum, if needed. (I've had to on other trucks).

You could try heating the drum, to expand it some. (not a great idea)

 

[dezert ratt]

Is it worth putting the front wheels back on, with the adjusters loose. Move the truck back and forth a few feet under its own power? Id hate to start cutting and breaking stuff. But if need be ill do it

 

[doghead]

That might help break something free if a part has come loose and is bound.

I would disconnect the air to the sprag, so you do not apply power to the front end, and break driveline components.

 

[dezert ratt]

i fiddled with the brake adjustments all morning. Finally got the drum semi loose. the top adjusters dont seem to be moving the shoes much when i look in the inspection hole while tightening and loosening. The bottom adjusters make the hub lock up completely if i turn them either way. When turned neutral ( between tight and loose) the drum will spin when i turn the hub with a pry bar. the adjusters dont feel like they are working right, compared to the driverside front adjusters. I am going to take the hub apart and further investigate whats goin on. Now i just need to go pick up a hub nut socket from napa, and start fabricating my "soldier B" to assist in removing the hub.

 

[doghead]

At the top, if your wheel cylinder is not retracting completely, you will not get the motion needed. Simply unbolting and partially rotating the wheel cyl may help.

You may be able to pry the shoe away from the drum at the 10 and 2 positions, with the bleeder open and adjusters set all the way in.

 

[dezert ratt]

i thought about it. I feel iffy about not taking it apart and checking the internals. The best bet at this point is to not take any shortcuts and do it right. While im at it, im gonna repack the bearings. I think the shoes should be loose enough to slide the hub/drum off.

 

[m816]

You locked the brakes up by tightening the bottom adjustment. Back off on the lock nut and work each side( bottom and top) a little at a time. I t should free enough to slide off then You would be better witha wheel dolly to remove the wheel. You take weight off the drum slightly by lifting it and get better leverage. Good luck

 

[dezert ratt]

So i found out my pass side front brakes are fubar. I need to get the right sockets next week for the bearing nuts, then im gonna tear down and replace everything that attaches to the backing plate. Im offically beat, and im glad im getting to know my new to me truck already! Its hard work, but definatley worth it!

 

[rrrr]

You are doing the right thing by doing the job right ! Congrats on getting it apart.

 

[Csm Davis]

Okay what was fubar? And just got to do it