Electric Brake Test Procedure

[Hexhead]

Could someone please provide a procedure for the testing of the electric brakes at the wheel and then at the trailer 7 pin connection. Should there be and audible click at the magnet? How much resistance to rotation should be felt with the wheel off the ground when the magnet is energized? I do not see continuity at the break away switch when the cable is pulled and feel it is defective? I am working to make my "new" 72 Overlander roadworthy. Thanks in advance!

[Ultradog]

the way they taught us to test the trailer brakes when I learned to drive a semi was to get it up to about 15 mph and apply just the trailer brakes.
It should stop Both the trailer and the truck in a few hundred feet.
Do that test every time you reconnect.
HTH
jerry

[uwe]

Originally Posted by Hexhead

Could someone please provide a procedure for the testing of the electric brakes at the wheel and then at the trailer 7 pin connection. Should there be and audible click at the magnet? How much resistance to rotation should be felt with the wheel off the ground when the magnet is energized? I do not see continuity at the break away switch when the cable is pulled and feel it is defective? I am working to make my "new" 72 Overlander roadworthy. Thanks in advance!

You should hear a hum with the brakes energized. The brake should be more or less locked up when energized and with the wheel off the ground, but it depends of course on the amount of voltage the brake magnets get.
If there isno contiuity on your breakaway switch with the pin pulled, then it it most likely defective. Time for a new one. How did you check it?

[Pick]

I Jordan brake controller has a built in ammeter. You can tell if your brakes are working, or if any magnets are bad, by the amount of current drawn.

[norsim]

One method I have found usefull over the years is to find a safe place to stop and pull over from 60/70 MPH using trailer brakes only and then feel of wheels to see if all are all about same temperature (caution they can be hot enough to blister your hand). If one or more wheels are cold or a lot cooler than others then that brake is not doing it's part in stopping vehicle.

[Pahaska]

that the electricl brakes are of the servo type. You must first apply the current and then roatate the wheel in the forward direction part of a revolution before the pads will be servoed out to contact the drum. Simply applying current without rotating the wheel far enough, you will not feel any resistance.

[Airstream25]

Originally Posted by norsim

One method I have found usefull over the years is to find a safe place to stop and pull over from 60/70 MPH using trailer brakes only and then feel of wheels to see if all are all about same temperature (caution they can be hot enough to blister your hand). If one or more wheels are cold or a lot cooler than others then that brake is not doing it's part in stopping vehicle.

I do a milder version of this in my gravel driveway every time I hook up for a trip. When rolling along at about 5 or 10 mph, I apply only the trailer brakes and let them bring me to a complete stop. Then I get out and check all four trailer wheels to see if there is a pile of gravel pushed up in front of each tire. This will indicate the possibility of one wheel not working.
Then I pull ahead to an undisturbed part of the driveway, get out and pull the emergency brake pin then get back in and attempt to drive away a short distance. I repeat the check in front of each wheel for the small pile of gravel.

[CanoeStream]

Pick sure likes the Jordan brake controller -- so much so that I have yet to check it out for my new GMC Sierra. A word of caution from jcanavera -- your breakaway switch activates the brakes based on the trailer onboard battery. If you have the umbilical hooked up to the TV and a Tekonsha brake controller and if you pull the breakaway -- you will fry the Tekonsha. You can test your breakaway switch without the brake controller wired in via the umbilical -- the whole idea is for it to work independent of losing the umbilical if you lose your load.

Listening for hum is one way but I wasn't able to appreciate that out in the fresh air and neighborhood sounds with my Argosy. I followed overlander64's advice and placed a standard compass on an upside down plastic bucket up against the inside of each axle-brake hub area. Pulling the breakaway caused the brake magnets to activate, swinging the compass needle. The swing wasn't great -- 10-15 degrees. But it was enough to check each brake and tell me the wiring was intact.

[WayWard Wind]

I've been told that while stopped for whatever reason with your foot on the brake, it can fry the electrial trailer brakes. The current draw is timed and increases despite weak or strong foot brake pressure. What say???
Best,

[CanoeStream]

Hey Al -- Inland Andy and others have the classical answer. (thanks for reminding on this particular point) The brake solenoids will burn out if you pull the breakaway and leave it pulled for as little as 4-5 minutes. Prove that they work, hook it back up again, and then leave it the heck alone. Don't know that I've heard too much about you in the driver's seat with your foot on the brake pedal during a long light. Makes sense that it could damage the brake solenoids.

One Forums participant mentioned a know-it-all yokel at a gas station took a shortcut across the hitch between this member's TV & Airstream. A toe must have dragged and pulled the breakaway lanyard. He would have lost all trailer brakes if he hadn't done his walkaround after an otherwise normal refueling. The walkaround is nearly indispensable!! Do it every time you start up and head out.

[wkerfoot]

Originally Posted by WayWard Wind

I've been told that while stopped for whatever reason with your foot on the brake, it can fry the electrial trailer brakes. The current draw is timed and increases despite weak or strong foot brake pressure. What say???
Best,

How long would this take to burn out the brakes? If you are stopped with an automatic transmission or are pointed uphill or downhill, you would have your foot on the brake pedal.

Bill

[WayWard Wind]

Bill---that's the question I've been wondering. Seems like it might be 4 to 5 minutes, but I'm not sure. I do know that my brake instructions says that voltage draw, to the brake magnets, increases from a timed period and NOT foot brake pressure. It'll be a mute problem for me, as I'm converting to the hydro system in July. Pricey , but peace of mind.
Best,

[WayWard Wind]

Has anyone read Dave S. (A/S), in the recent BB, regarding the tube hitch problem on the Chev/Sierra? Appears they may have a problem with twisting.
Great!!!! Just purchased a 06 2500. Might just need those brakes .
Best,

[CanoeStream]

No, I hadn't heard of an actual tube hitch problem. Do you have a URL web link on this?

I'm not surprised as I had noticed that the 2" I.D. square tube on my 2006 GMC Sierra 2500 has welds 3" at the longest, almost half what it was in my former supposedly-wimpy Nissan Titan. Hmm....

[CanoeStream]

I guess this would really, really, really make one think twice about the extra flex as reported with the extra hitch length added with an Air Hitch.

[WayWard Wind]

the article didn't give any url's, but quoted an A/S owner that had the problem and then related it to Dave S. The article in the Blue Beret went on to say that GM RECOMMENDED the round tube hitch should be replaced with the square type. Can you believe they would say this? Needless to say I have brought (gave them a copy of the article) this to the dealers attention and want a letter stating the round style hitch is approved for use. If not I /they have a problem. Of course the dealer says they've NEVER had a problem and several of thier employees have towed heavy trailers with no problems. What else is new!!!! Tell that to the judge after something terrible happens!!!!!
Best,

[Hexhead]

Thanks to all for the great suggestions which were most educational for me. I've installed a Tekonsha controller in the Ford and in combination with their setup advice I've verified "normal" brake function. No long trips yet!