Brake Help Needed...

[mconstable]

This one has me puzzled.

Trailer brakes are electric over hydraulic, controller is Prodigy.

Halfway through our trip, going down an off-ramp, I noticed things weren't slowing very quick so I pulled the manual lever, and nothing... trailer brakes weren't working at all.

... and controller wasn't throwing any codes, settings were fine.

I am clueless on this one, any advice?

 

[Mark31]

mconstable, I had a Prodigy (moved to another truck) and a Carlisle Hydrastar electric over hydraulic unit. The Prodigy (and factory Ford controlers) wasn't compatible without a add-on to the brake unit. At one time , I understood that it was about $80. I would consult the brake manufacturer. I now have a Tekonsha P3 unit which can be switched from electric to electric over hydraulic and am pleased with the performance. Hope you get 'er sorted out! Mark

 

[mconstable]

Thanks Mark... would it make sense that it worked for most of the trip, and didn't throw any codes?

 

[Mark31]

mconstable, maybe the condition that triggered the code didn't occur until that part of the trip. Try checking the manufacturer's web site for compatable controlers and frequently asked questions or maybe their customer service dept. I wish I could help you more, but I'm neither a rocket scientist or much of a wrench. Mark

 

[FJfonda]

Diagnose it

Start with the basics, an electric over hyrdraulic set up is simply hyraulic brakes supplied by a high pressure hydraulic motor which is controlled by a cab controller. I had my Carlisle electric over hydraulic pump unit fail in the middle of a trip ... . then the next year my controller failed. Here is where I would start:

- A quick controller check is to put a bug light on your trailer connector on the truck... . pressing the brake should make it light. A meter may not work depending on your controller as it needs to "see" a connection and the meter will not draw enough current to make that happen.

- All electric over hydraulics make noise when running --- have someone listen to the unit while actuating the brakes. If it is making noise, check the fluid level and inspect for a leak on the hydraulic lines.

- If no noise, pull the breakaway clip out of the holder and this should give full braking from the breakaway battery system. Listen as in above. If no noise, the it is a pump or truck/trailer wiring problem. If you now have the pump running and it was not before, then it is the controller or truck/truck wiring.

- Of significant note: Electric over hydraulic controllers draw more current that most vehicles are wired for. The signal from the controller is just that -- a signal. The current to run the pump is actually coming from the +12V pin on the trailer harness. I had to run #10 wire to supply the required current on my truck ... . it may just be a blown fuse in the truck +12V supply which is a simple check with a bug light.



To expand on the compatibility of the controllers ----- most smart controller send a test signal every so often to the brake system to verify the trailer is connected and the brakes are functioning. On electric brakes, this simply sends a quick pulse through the coils and no big deal. On electric over hydraulic controllers this pulses the motor and over time caused premature motor failure. I would check on the Prodigy compatibility --- I went with a Primus for that exact reason.



Let us know how you make out!

 

[mconstable]

Well... never take anything for granted!

Trailer is brand new, so I never checked the fluids, of course the hydraulic pump was bone-dry.

filled it today, will bleed it later, and am going to pick up a compatible controller tomorrow.

Thanks for the help guys.

... and FJ, thanks for the troubleshooting tips, did the tests, and the pump is good, now I just have to find if, and where I have a leak in my system... could be worse, the trailer brakes failed about 5 miles from the campground I was headed to... found out just how hard it is to stop a 17,000 lb trailer with just truck brakes! lol

 

[FJfonda]

mconstable,

If you can't find the leak it may be an internal leak on the electric over hydraulic unit -- just before mine failed it was "using" fluid over time, Turns out the pump had leaged into the cavity it was installed in within the unit.



We were 7 hrs from home when ours failed, just finished pullng the boat our of the water and thought the no-brakes were just wet linings ---- 5 miles later, still no brakes. Holiday weekend, no parts, lotta traffic... ... . got it working but only had 70% brakes. Made for a very slow, long ride home.

 

[GAmes]

I have a prodigy and have pulled a few elec/hyd braked units with no problem. One went fron Ft. Myers, FL to Seattle. They are compatable, at least the new ones are.

 

[B.G. Smith]

I too have trailer with electric/hydraulic disc brakes. Had a Prodigy when I first got the trailer (2003) and it work intermittenly. Ended up with a simple Reece controller that is time ramp but it can be set so you don't flat spot the tires. Mine has boiled the fluid back up and out of the reservoir a few times, kept seeing liquid in bottom of compartment where the servo is mounted, could find no leaks but it was being forced out the filler cap with cap in place. Seems to happen when I get cought in a lot of stop and go traffic. bg

 

[FJfonda]

B. G. ,

Excerpt from my controller's operating manual:

" Extended stops can generate excessive heat - when stopped for extended periods (i. e. such as rr crossings and traffic jams), apply the parking brake on the tow vehicle and release the service brake pedal so that the Hydrastar actuator does not run continously. Failure to follow this guideline will cause the Hydrastar unit to overheat and will damage the Hydrastar unit. "



This was a big suprise to me ----



Rest of guidelines here -- http://www.carlislebrake.com/pdfs/HydraStar_SM.pdf

I too have trailer with electric/hydraulic disc brakes. Had a Prodigy when I first got the trailer (2003) and it work intermittenly. Ended up with a simple Reece controller that is time ramp but it can be set so you don't flat spot the tires. Mine has boiled the fluid back up and out of the reservoir a few times, kept seeing liquid in bottom of compartment where the servo is mounted, could find no leaks but it was being forced out the filler cap with cap in place. Seems to happen when I get cought in a lot of stop and go traffic. bg

 

[Mark31]

FJF, I am under the impression that if the breakaway plug is pulled without disconnecting the controler, the controler will be fried. Is this correct? Mark

 

[B.G. Smith]

B. G. ,

Excerpt from my controller's operating manual:

" Extended stops can generate excessive heat - when stopped for extended periods (i. e. such as rr crossings and traffic jams), apply the parking brake on the tow vehicle and release the service brake pedal so that the Hydrastar actuator does not run continously. Failure to follow this guideline will cause the Hydrastar unit to overheat and will damage the Hydrastar unit. "



This was a big suprise to me ----



Rest of guidelines here -- http://www.carlislebrake.com/pdfs/HydraStar_SM.pdf

Thanks for the info. That is the exact unit I have. I installed a switch in the line between the in cab brake controller and my stop light switch so I can hold my foot on the brake and still not have the trailer brakes avtivated. It is a push button that is NC, I have a toggle switch mounted on the side of it to by-pass the push button should it fail to make contact. This is all mounted on two wires with about 2' of slack so I can keep it in my lap when in stop and go traffic. On th road I just stick it in one of the cavities around the radio/AC control. bg

 

[FJfonda]

Mark,



I pull mine for verification before each tow --- always connected to the truck. That may depend on the brand controller but it worked OK for me using both a Reese timed based controller and the Primus I am using now. The only controller failure I have had is a Primus and it seemed to have been exposere to cold weather that did it in. Worked in the fall, didn't in the spring.

FJF, I am under the impression that if the breakaway plug is pulled without disconnecting the controler, the controler will be fried. Is this correct? Mark

 

[FJfonda]

That is a good idea -- when you push the button does it throw a fault code on your controller?

Thanks for the info. That is the exact unit I have. I installed a switch in the line between the in cab brake controller and my stop light switch so I can hold my foot on the brake and still not have the trailer brakes avtivated. It is a push button that is NC, I have a toggle switch mounted on the side of it to by-pass the push button should it fail to make contact. This is all mounted on two wires with about 2' of slack so I can keep it in my lap when in stop and go traffic. On th road I just stick it in one of the cavities around the radio/AC control. bg

 

[B.G. Smith]

That is a good idea -- when you push the button does it throw a fault code on your controller?

No, I don't think my controller is smart enough to throw a code. The switch is between the stop light switch on the truck and the controler so when the button is depressed the controller sees same conditions as when the brake pedal is not depressed. bg

 

[Mark31]

Folks, browsing Brakecontroller.com, I learned a couple of things: 1. The Tekonsha P3 is listed as a "next generation" unit. I had thought that it was only a Prodigy with the ability to work electric/hydraulic brakes. Maybe it has some other "smarts" too. 2. Clicked on "proportional comparisons" and found that Prodigy is listed as not electric/hydraulic compatable. Mark

 

[B.G. Smith]

Folks, browsing Brakecontroller.com, I learned a couple of things: 1. The Tekonsha P3 is listed as a "next generation" unit. I had thought that it was only a Prodigy with the ability to work electric/hydraulic brakes. Maybe it has some other "smarts" too. 2. Clicked on "proportional comparisons" and found that Prodigy is listed as not electric/hydraulic compatable. Mark

I had a Prodigy when i first got the trailer, flat spotted a couple of new tires before i got out of sight of the house. I don't know what generation it is supposed to be. I would like a little better controller if I could get one without an arm and leg, there is very little info that I can find on controllers for electric/hydraulic disc brakes. bg

 

[mconstable]

Thanks for all of the help guys... filled the actuator, bled, put on a P3 controller... will tow tomorrow and update.

did some research on wiring diagrams and schematics between the Prodigy and P3, looked like they were interchangeable units harness-wise, and they are.

 

[FJfonda]

My Primus works beautifully with the electric over hydraulic setup and is listed as compatible.

I had a Prodigy when i first got the trailer, flat spotted a couple of new tires before i got out of sight of the house. I don't know what generation it is supposed to be. I would like a little better controller if I could get one without an arm and leg, there is very little info that I can find on controllers for electric/hydraulic disc brakes. bg

 

[Ramtough]

I had an interesting experience with my new Hitchhiker with hydraulic brakes. Symptoms close to what you're describing. The dealer was going to replace the pump under warranty. As they were getting ready to do this, they noticed the failure was intermittent. Turned out that there was a 50 amp buss fuse in the trailer's brake circuit under the nose near the trailer end of the pig tail. The fuse had become loose on one end and was breaking contact. One of the fuse caps had become loose! The problem may not be in your controller or the trailer brakes.