Trailer brake drum problem

[Denis]

Have a dual axle trailer with electric brakes. Brakes are stuck on one wheel and I cann't get the drum off to see why. Other 3 wheels are free and have backed off on the shoe adjuster on the stuck wheel but still no getting it off. Any ideas to get it off??

 

[MAllen1]

Have you tried backing the trailer up with or without the trailer brakes applied?

 

[jelag]

Sometimes when the shoes wear into the drums, there is a ridge on the edge of the drum that won't allow the shoes to pass when you go to remove the drum... .

You need to back off the star adjuster for the shoes... remember that one turns clockwise, and the other turns counter clockwise to retract the adjuster..... If you have one off at this time see which way it turns to retract the adjuster, and put a brake spoon or screw driver into the slot for the other side and turn the star adjuster and retract it...

If the brake drum is that worn, I'm going to guess that its bad, however anyone who knows how to turn these drums can true them up, and turn the surface that the magnet runs on...

On all vehicle drums used on the road is a DOT standard that can't be exceeded... this is the minimum thickness the drum will function at safely...

Hope this helps... .

MAllen1 is right... . back up but do not apply the brakes... some trailer axles have self adjusters on them so they ratchet tighter when backing and applying the brakes... this would make your problem worse... but if they are stuck from rust in one direction then this might free them. .

BTW - the parts are side specific... that means the parts from the left side(drivers) do not work on the right side(passenger)... You can purchase complete backing plates, with all new parts attached to the them for easy assembly... I'm sure what your going to find is that the one wheel, had some of the parts come loose and damage the complete assembly...

 

[Denis]

Trailer brake problem

Have tried going foward and backwards with brake on and off. Drum is locked up either way.



Am unable to loosen the adjustment stars; as they must be rusted. The drum is locked tight by the brakes and I can't seem to loosen the shoes. What to do?? Have tried a very large puller but to no avail. Is breaking the drum the only way to get it off?

 

[jelag]

Look on the back of the backing plate and see if the backing plate is bolted to the AXLE... usually a 4 or 5 bolt pattern... if so, with some luck you can pull the nuts on the back of the backing plate allowing the bolts to fall into the drum... we try and get an air wrench into these nuts to spin them off with force that you can't sometimes get them off by hand... .

With the bolts removed you can than pull the drum backing plate and brakes... make sure the wires are dis-connected from the backing plate...

Once you have this assembly out, the large axle hole in the center of the backing plate will allow you to reach in and remove the hold down springs and hopefully release the shoes and take it apart...

I've never personally had one we couldn't get apart but I can see your point. . and understand how this can happen... If the drum pulls out at all... I'd drop an allen wrench or a screw driver with a hook on the end of it to see if the drum is really worn...

If I thought the drum would be scrap, because of the wear... I'd just smack it with a 16 lb sledge and break it free to save the time... on the other hand if I thought it was good and re-useable I'd do what I could to salvage it...

 

[Denis]

Success

Got the drum off today after much proding and Liquid Wrench. Took the other 3 drums off to check them.

Last time I used the trailer brakes seemed fine; however I was amazed with what I saw when I removed the drums. The Axles are 7000# with 12 x 2 Dexter electric brakes. The inside of one drum was covered with grease as the seal had failed. 2 of the other drums had the lining seperated from the shoes; one shoe didn'd even have a lining on it although drum was not scored. Have no idea where it disappeared to. Seems like only one brake was working.

Any comments??? Are these Dexter brakes any good or is my problem just a fluke? Had the trailer about 5 years; bought it new and only have about 5,000 miles on it.



Thanks for the help and any comments.



Denis

 

[jelag]

Denis.....

I have several trailers all using the dexter axle, with no problems... at least once a season we open each up and inspect them... .

We do a lot of friction... . if the friction is not correctly bonded to the steel when its made and moisture gets between the steel and friction it can rust... once the rust starts... it spreads under the bond and lifts the friction... .

We have to dip the processed steel (Grit blasted) in a chemical that works as a rust inhibitor, sort of like a cleaner prep used on plastic pipe... we dip the steel within 15 min of cleaning...

Once this dip cures (drys) it can sit for days... later we blow it off with air to remove dust, and apply a chemical bonding agent (glue) and attach the friction to the table(face of shoe) under pressure... this is time baked in an oven to specific temperature and time (time bake) based on the weight of the steel and size of the friction to get the base temperature of the bond to the correct temperature... than it air cools... we actually insert a small probe into the bond line to insure the correct temperature...

Anytime this process is shortened or dirt is introduced the bond is not good...

We have offered our customers riveted lining, but this has a much shorter life as the head of the rivet limits the life of the friction...

BTW - you'd think that grease would make friction slip, it actually makes it grab... and the grease can't be removed... we've seen people actually try and bake the grease out... but this can shorten the life of the bond causing it to fail...

Hope this overview of the process is not to long and helps you to understand whats happening...

 

[Denis]

Great Info

The brakes did have a good bit of rust on them; I guess that's what happened to the lining on the shoes. Lifted off as you said do to rusting and/or poor bond.

What type of finish is required on the magnite surfaces of the drums? Local machine shop wants 9. 00 to do the brake surface but 20. 00 to do the back of the drum.

I checked on prices and it is much cheaper to buy the entire brake backing plate assembly. Hopefully I can get the drums turned. This and a new breakaway battery and I'll be all set. Really appreciate the info.

Thanks

Denis