Back-up solenoid troubles!!!

[Mike Tosello]

I have a 2001 929 and am having troubles with the back-up solenoid, this is the 2nd time i'll be replacing it and it really starting to piss me off. Was just wondering if anyone else has had the same problems and what they did or why they think it keeps failing. Taking the hydraulic brake actuator apart to replace them is a pain in the arse...



Mike

 

[Herndonpro]

Are you sure you don't have air getting in line or system? Have you tried bleeding the brakes, before replacing the selenoid?

 

[Jim B]

You may also want to check your ground on the trailer and the truck before you replace it. A bad ground could cause it to work intermittantly. I have never heard of one of these failing, i have had the rubber return line fail but never the unit itself.

 

[Bryan McDonough]

Yes the ground wire often goes unoticed. I made the brake actuator hose a lot longer by 18 inches.

 

[Mike Tosello]

i have tested the ground and the power source ( wire from the backup lights on truck) and everything is checkin out fine. And I dont think air in the lines would cause the brakes to lock-up when backing. Its too cold to go out and mess with it anytime soon, but it will be my first project when weather permits.. I've had many trailers in the past and have never had this problem before.



Mike
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[Michael Snow]

Okay, is there possibly a bad connection to the connector?



No, what you're experiencing is NOT normal.

 

[Mike Tosello]

Mike, i used a 12v tester and got positive readings after the connection when the truck is in reverse. Dealers and mechanics have told me that when shifted into reverse, i should hear a clicking sound coming from the tounge of the trailer ( solenoid ). I do hear a click, but they tell me it should be louder that what i am hearing. I have to put my ear to the metal to hear it. I will check all connections and grounds again before i tear into the acuator but it seems hopeless. thanks



Mike

 

[Jim B]

what you may want to do it take a 12 volt battery and hook a wire from the neg to the ground terminal on the 5 pin connector on the trailer and the pos to the reverse wire(blue). if you connect and disconnect the battery you should hear or feel the solenoid click when power is applied to it.



I still think you may have a ground problem. under the toung of the trailer you will find a white wire screwed to the trailer. Unscrew the wire and make sure the spot where is contects the trailer is free from rust and the the screw is in good shape. If you dont have a good ground you wont get good current flow and if you have your brakes pressed when you put it in reverse you may not be getting enough current to make the solenoid go. I have seen some pretty strange things happen from bad grounds. for example last summer i had to repair my fathers trailer for him because during the day he had two brake lights and everything was fine but at night with the running lights on he only had one tail light, the other was completly out. The cause was the ground connector and screw was rusted and needed to be replaced. Once you get everything checked out on the trailer take a look at the truck too.

 

[Mike Tosello]

Jim, thanks for the advice... and everyone else aslo. I do believe that my problem has to be in the wiring somewhere now, I just dont see these solenoids going out this much... I will get to the bottom of this, getting out of the truck at the ramp is a pain in the butt, not to mention a little embarrassing LOL Thanks again,



Mike

 

[Scott Hammer TOXIC]

Mine is finicky when backing UP a slight incline. Also will not want to back up flat sometimes. I just drop the truck back in gear, then back in to reverse. Most it has ever taken is three times.



TOXIC