Re: [A/S] Electric Brakes & Controllers

[Jim Dunmyer <jdunmyer@xxxxxxxxxxx>]

James,
 If you've ever worked on anything with drum brakes, you know all there
is to know about electric trailer brakes:

They are NOT self-adjusting, you need to use a brake spoon, just like in
the Olden Days. Procedure is the same, tighten 'em up until you have a
heavy drag, then back 'em off until there's no drag, maybe just a slight
rubbing noise. While you have it on the jack, test the brake action by
spinning the wheel and pulling the breakaway pin or use the controller
on the tow vehicle. (DO NOT pull the pin while the tow vehicle is
plugged in, some controllers can be damaged!)

Of course, you'll check the condition of the brakes when you do your
annual bearing repack & seal replacement. I like to remove the adjuster,
clean it, and coat the screw with grease or anti-sieze lube, making sure
that it works freely. Always install them in the same direction so that
you know which way to move the spoon when adjusting them. WHICH
direction is unimportant, just so you know.

If the linings or magnets are bad, always replace both sides of a given
axle, never mix 'n match parts. Speaking of magnets: they're iron, with
a small brake lining. When energized, they rub harder and harder against
the 'armature', or disk on the face of the drum, pulling the acutator
lever to apply the brakes. I always check the operation by moving the
lever back and forth before reinstalling the drum. If things are less
than perfect, I always disassemble the entire brake, clean up the
components, LIGHTLY lubricate the wear points, and reassemble.

If you fill the entire hub with grease, you'll almost certainly have
some of it pushed out past the seal and contaminate the linings. Brake
linings that have gotten grease on them must be replaced, they'll be
very grabby in operation. Again, if you replace one, do the other side
on the same axle.

Adjusting the bearing is also very simple: tighten the nut with
something like a ChannelLock Pliers until it's snug, but not overly
tight. Spin the wheel and double-check tightness. Then, loosen the nut
and install a new cotter pin in the first available hole. I like to
'feel' the tightness by snugging the nut, then backing it off. You can
feel when it goes 'loose', and that's where you install the cotter pin.
You should not feel ANY looseness if you grab the top of the wheel and
yank it forward and back. Of course, the wheel should rotate without any
undue noise, rumbling, excessive drag, or scraping.

Although some folks use regular grease on the bearings, I always use
wheel bearing grease. You can wash the old grease from the bearings AND
hubs with mineral spirits or even gasoline, using a brush of some sort.
When I was a kid, I used an old toothbrush, which will still work.
Remember that you want the bearings and hubs hospital-clean before
repacking! If you don't know how to pack a bearing by hand, it might be
nice to get someone to demonstrate the technique. You don't simply smear
the grease on the rollers, you must "slice" the bearing assembly into
the pile of grease in your (CLEAN) hand, as though you're trying to cut
your hand with the edge of the roller retainer. Rotate the bearing,
doing it again and again, then flip it over and repeat from the other
side.

Carefully install the new seal by tapping it in with a small hammer,
going 'round and 'round to make sure it goes in square. Smear just a bit
of grease on the lip of the seal and on the (CLEAN) spindle where the
seal rubs. When you install the drum and drop the outboard bearing,
retrieve it, clean it, and regrease. Not a SPECK of dirt may be allowed!

Bearing packing, seal replacement, and brake checks/adjusting is
something that's too important for me to leave to a "professional". If
you have a competent professional, more power to you, but they're not
that common. This isn't rocket science; if it 'feels good', it probably
is, and the converse is also true. Tool requirements are minimal, the
only specialized tools that I use is a brake adjusting spoon and a
universal brake pliers. (spring tool) Those tools and all necessary
parts are available from any good auto parts store such as NAPA.

Sorry 'bout the wrong order of things, I just got carried away and wrote
up the entire procedure and am too lazy to do a bunch of cutting &
pasting to make it right. <<grin>> You probably know it already, but
some of the other folks might be interested.

                                            <<Jim>>