I have a 2004 Keystone Laredo 27RL. This unit has Al-Ko axles on it with 2" by 12" drums. This weekend I repacked the bearings and checked the brakes and reset them. The shoes have very little wear. When I reset the brakes I turned the starwheel up to where there was good contact and then backed them off to where I can just feel the pad making light contact with the drum. All four brakes work but not very good. I have a Jordan brake controller and with the gain turned way up I can get up to 11 amps on the digital readout. I can hardly tell that the brakes are working when I push the manual brake controller as I drive.
Is it possible that the magnets are loosing strength? What else am I missing?
Stan

 

The magnets have little dots depressed in them on the face that rides against the drum. That is the wear indicator. When they are worn flat, they begin to loose their strength. The wires also can deteriorate from the constant movement and vibration inside the backing plate causing fade.
How worn were yours when you had it apart?

 

I'd bet you may have them adjusted too far back.

Run the star out until the tire/wheel will not spin by hand, to center the pads.

Then back the star off until the wheel turns freely, plus about 3/4 of another turn (about 5 bites).

 

I do like Jeff says. Run them down tight and then back them off till I can turn them and a bit.

The magnets wear out over time from rubbing against the drum but if you had the drums off that'd be pretty evident.

 

I normally do the same.. Run them in till the wheel wont spin by hand and back off till there is a light drag...


Biggest problem I normally see with electric brakes on trailers is using small gauge brake wire and/or small grounds... Have somebody hold the emergency brake level all the way and check the voltage at the brake drums... When small wire is used you will see a large voltage drop at the brakes causing a decrease in performance...


As always with trailer electronics CHECK YOUR GROUNDS!! they may make the lights work, but still not have enough juice to throw 15 amps at your brakes and another 5-10 amps to all your lights... Big grounds are key!

 

Your controller is telling you the right numbers - - 2.5 - 3 amps per magnet is normal. Mine is down to 10 right now - - I probably have one corroded connection.

Run out on a dirt road somewhere and going slow, hit the controller and see if you can lock the wheels up on dirt. If so, which wheels? If none, you have a problem. Just because the magnets pull current does not mean they are working right. The lockup test can give you some idea of what is, or is not, happening.

A good brake adjustment does wonders on my rig.

Bob

 

Seems like the magnets are good for 2-3 years, then need to be replaced, just my experience. I am sure the ground and wires are also very important.

 

I'd guess from the amps being pulled, magnets, ground and wiring are OK.

If double checking the adjustment doesn't help, and they have been sprayed off with good brake cleaner and are free of dust or grease, the shoes might be a bit glazed and scuffing them up with some emery cloth might help.

My guess is still adjustment, however.

Both Dexter and Al-Ko have very nice downloadable pdf manuals for free.

Under "Service Information" select complete service manual.

http://www.dexteraxle.com/products___literature

And here, just click on "Owner's Manual".


http://www.al-kousa.com/

It is worth it to save both to your hard drive.

 

Thanks for the information. I am tight on time right now and will not be able to check into this for a couple of weeks.
FiverBob, I did try pushing the manual brake activator on the Jordan controller and there is no way any of the wheels would skid. Could not really tell that I did push on brake activator. I have several other trailers and the brakes are very good so I know it is not the controller.
I should try the ground with a jumper cable between the truck and 5er. That would not take long.
These axles have the easy lube feature with the grease zerk on the end of the axle. I was afraid I had over greased the bearings and got grease on the brakes but no grease was pushed out of the seals. I cleaned all the dust off the drums and shoes with brake cleaner when I had everything apart.
If the magnets are weak will they still draw the normal amps?
Thanks again guys.
Stan

 

I would pull the drums off and make sure the magnet levers are free to pivot without binding. It's pretty common to see the levers get seized.

I have a much simpler and more accurate way to adjust the brakes. The wheel doesn't need to be jacked up. Simply crawl under the trailer, stick a flatblade screwdriver into the adjuster slot and pry the starwheel back and forth. The amount you can move the starwheel indicates the gap between the linings and drum. Adjust up the brakes until you can only pry the starwheel back and forth 1/8 of an inch. That brake is now perfectly adjusted. Repeat with the other wheels. Give it a try.

 

No amount of shoe adjustment is going to make weak electric brakes take ahold.

What spreads the shoes and stops the trailer is the pitiful little electro-magnet becoming electrified/magnetized and trying to stick itself to the flat inside face of the rotating brake-drum, thus causing the lever it hangs from to pivot and spread the shoes via the square cam; in exactly the same manner that cable-operated park-brakes work.

My experience has been that you either have slam-the-trailer-backwards-and-hop-the-wheels, all-or-nothing brakes, or you can't feel any help from them at all.


Make sure the entire HOT wire system that starts at battery-HOT, proceeds through the brake-controller, onward to the trailer-plug, through the trailer, and finally the wheels themselves is of at least 10AWG, CLEAN and soldered.

Use the same or larger wire for all wheel GROUNDs, grounding them at the trailer-frame, CLEAN and COATED, PLUS route a same-size GROUND wire back through the trailer-plug and all the way to the engine block GROUND (where the big cable bolts to).


Now, BYPASS the brake-controller through a BIG toggle-switch.

Get all trailer wheels off the ground.

Pull off all drums.

Inspect the riding corners of all magnets to make sure none have worn through into the white plastic layer.

Once through the plastic layer, they wear into the copper windings, thus making a dead short and killing the whole system.

In a pinch, out on the road somewhere, you can clip the wires to the offending magnet, thus taking away the dead short and allowing the remaining wheels to have magnetism.

Now, take a big heavy steel wrench or whatever, and with an assistant in the truck, hold the steel an inch away from each magnet.

Have them apply the brake and see if the magnet instantly and forcefully jerks the steel against it; do this at each wheel.

While the drums are off, lubricate all contact points and pivot points, and coat the entire length of the star-wheel threads with anti-sieze.

If needed, deepen the star-wheel teeth with a triangle-file.

Put the drums/tires back on.

Now, get a tire/wheel spinning as fast as you can, then have your assistant hit the brakes.

The wheel should BAM!!!! and stop instantly;you should not be able to rotate it.

Try this at each wheel.

If any wheel fails any part of these tests, inspect all components to that particular wheel and find out why.

If all wheels seem weak and sluggish, try the tests with the toggle-switch by-pass, thus putting full voltage to the magnets, taking the controller out of the loop; apply the toggle only momentarily, as constant power to the magnets is equivalent to a dead short, and things will start to get hot.


Run up the adjusters and try to scoot the wheels at a slow speed.

Have your assistant watching to see which tires are scooting and which are simply rolling.

Occasionally, a drum will get magnetized and actually repel the magnet, instead of attracting it.

When this happens, it is nigh impossible to diagnose.

You can attempt to remedy it by switching wires at that magnet; sometimes it works, most times it doesn't.


There are so many things that can go wrong with electric brakes, that many trips are made with no brakes the last portion of the drive.


The only real cure for electric brakes is to convert to vacuum-over-hydraulic.

 

(Nice post, BearKiller; one I saved to file.)

 

HOLY SMOKE - - WAIT A MINUTE. I just re-read your original post. You cleaned you drums with brake cleaner. Voallllaaaaa. Take the rig out on the highway, get up to about 60 and gently manually apply the controller to about 5 amps for a short distance. Let it cool - - do it again. do it again. do it again. Get the idea. Burn that cleaner back off the drums and linings. I had a mechanic pack my bearings last time because I was too busy and heading out on a trip. Picked it up with no brakes. Took it back and had him adjust brakes while I watched. Still almost no brakes. Then he let slip he had used brake cleaner on the drums. I have had it happen before. Did the above routine - - took about 15 miles of working at it before I started getting half decent brakes. 50 miles and they were normal.

Have fun,

Bob

 

Bob,
are you sure about that?

I just rebuilt the brakes on my boat trailer, cleaned the drums and shoes w/ brake cleaner and did not have a problem with brake application. 2 months ago, went through the brakes on my buddies boat trailer and had no issue using brake cleaner before final assy. Been doing this practice for the last 20 years on trailer and automotive brake and clutch systems. NEVER had an issue traced back to the brake cleaner. Over lubing the bearings, and maybe sloppy grease use, but never the brake cleaner.

Brake cleaner is a high vapor pressure / aromatic solvent. It is designed to thin and remove grease and oil from brake friction parts. I wonder if the bearing grease was not totally cleaned off the shoes/drums? It sounds more like you were burning any grease off the shoes/drums.

I'm not bashing your opinion, just questioning the results.

Tony

 

Question away, Tony- - that is what the forum is all about. Had two brake specialists tell me never use cleaner on the hub or near the linings. I sometimes think the mechanic can get some grease on the hub and linings when putting it all back together from their greasy little fingers - - not discounting that. They recommend wiping it all down with a clean rag - - do not blow it all out. Sure worth a try in seeing what it will do - - right????