Poor brake performance. Even after new brakes.

[dznf0g]

I got to thinking about something after I went to bed last night. You state in post # 1 that with the breakaway switch pulled you have only 11 volts at the hubs...right? AND you have only 11.x volts at the rear bumper TV connector (with the umbilical disconnected and the trailer batteries at 12.6 V?)? I am back to thinking you have two problems.

[Bigventure]

Originally Posted by timmaah

Ugg yes you are correct.. You'd think a grown man could keep them straight.

I put the lefts on the driver side / street side. The arm the magnet is attached to is facing forward.

My post 5 i stated it wrong.

On a drum brake the longer shoe is on the front the shorter shoe is the rear. There are no left and rights. The shoes could have been backwards to begin with. That would explain why they didn't work to begin with.
Look here:
10" Electric Brake Assembly RH, Hayes Hayes Trailer Brakes 60202703

In this photo the front is on the left.

[ROBERT CROSS]

Originally Posted by Bigventure

On a drum brake the longer shoe is on the front the shorter shoe is the rear. There are no left and rights. The shoes could have been backwards to begin with. That would explain why they didn't work to begin with.
Look here:
10" Electric Brake Assembly RH, Hayes Hayes Trailer Brakes 60202703

In this photo the front is on the left.

Big shoe little shoe still applies but it's the magnet arm that determines right and left with trailer brakes, the arm must face forward.



Bob

[dznf0g]

And good supply voltages and grounds must be present for any of them to work!

[GCinSC2]

Wild shot, any chance to try a different TV with your,trailer? Or try your TV on a different trailer. Purpose would be to isolate.

Good luck.

[crispyboy]

I had a similar trailer braking problem and ended up buying a new controller (maxbrake). The 5 year old Prodigy controller seemed to work some but didn't seem to put out the power of the newer controller. I borrowed a different tow vehicle before I bought the controller.

I do have a question when it comes to splicing the wires together.
The trailer has a main duplex jacketed brake wire going towards the axles. When it gets to the axles the single wire gets connected to the duplex jacketed brake wire from each wheel.
What is the best connection at the 1 wire to 4 wire (actually 2 wire to 8 wire) junction to get the least resistance?
1. large wire nuts like the factory
2. a small junction block with each wire having an eyelet soldered onto the wire and bolted to the junction block

[ROBERT CROSS]

Some will say solder and shrink wrap.

I have used marine connectors that come with shrink wrap on them.

I keep a selection of the heat shrink in the AS tool kit for repairs on the road, no solder needed.

Bob

[crispyboy]

Bob,
Before I replaced the controller I replaced the brake wiring in the trailer. Used a 10 ga duplex jacketed wire and then went to 12 ga jacketed duplex wire out to each wheel. A terminal block was used at a point in front of the axles where the 10 ga met the 12 ga. wire. I was curious if the terminal block is a good way for this transition or should have I just used simple wire nuts.

[ROBERT CROSS]

Steve,

The stuff you used is similar to this?...


Note the yellow wire connections here have used the marine terminals.

The wiring looks fine. If the junction block is exposed it would be susceptible to the elements. I would wire directly using solder/shrink wrap or marine connectors.

Bob

[Sav'h Steve]

I was getting very little braking with Prodigy turned up to as high as it will go. I have a 1990 25'.
Only one wheel would lock on loose gravel.

I know that when I had a problem on the road I had to do some remounting of the brake mounting plate bolts and I may have touched the pads with my greasy fingers not realizing it could / would affect the brakes.

Well I took the trailer to a trusted shop who routinely does trailer repairs, and he went through it and adjusted the brakes with no different results. Then he took a new controller and hooked it up with same results. Paid him for his time and decided to replace the backing plates as the OP did.

Well that is done and I still have the same (almost no) brakes. I did carefully clean the drum with brake-clean and was very careful not to touch the pads or the magnet. They are not adjusted up yet, but I still get the same results.

Now I haven't done any amp testing. I assume you have to cut the wire at some point and insert the multimeter on *20 amp* setting to check that with helper hitting the brakes (or pulling the breakaway).

I am thinking that I may have a wiring issue and may try what Rich said (I highly value his posts - Rich adds a lot to this forum) and run a patch cord from the controller out-put (Blue wire=trailer elec brake feed) back to the umbilical connection on the truck.

The only other thing I noticed is that several years ago my trailer plug dragged for a ways and wore down the outer wrap and the light blue wire wrap for 1/2". I immediately elec taped it and just checked it today and it the wire was bright copper and looked good. (Original 1990 plug) Just thinking what may be the problem.

[Sav'h Steve]

Originally Posted by idroba

Rather than checking voltage, or resistance, the easiest thing to do is to check the current the magnets take. Find the + 12 volt pin on the 7 wire trailer plug. Find the brake wire on the plug. Put an ammeter between those two wires. Properly operating wiring should result in 2.5 to 3 amps per wheel, or 10 to 12 amps total for a 4 wheel setup. If you are not getting that reading there is some electrical issue to deal with, from corroded wires to poor grounds. If you read the full current, then there is probably something wrong with the brake setup itself (shoes, adjustment etc.)

Not sure how you do this. If I pull the trailer plug-in the Prodigy will show 'disconnected'. Are you pulling the brake wire off the back of the 7-way and then checking amps? Just trying to picture how this is done.

Thanks for anymore precise info of how to make these checks!

Steve

[timmaah]

Originally Posted by Sav'h Steve

I was getting very little braking with Prodigy turned up to as high as it will go. I have a 1990 25'.
Only one wheel would lock on loose gravel.

I'm going to put it to the test tomorrow on the 20 miles into Durango. We will see what a little usage does to it. Otherwise I'm stopping at Napa to get some wire.

Thanks all.

[idroba]

Need some instruction....
Quote:
Originally Posted by idroba
Rather than checking voltage, or resistance, the easiest thing to do is to check the current the magnets take. Find the + 12 volt pin on the 7 wire trailer plug. Find the brake wire on the plug. Put an ammeter between those two wires. Properly operating wiring should result in 2.5 to 3 amps per wheel, or 10 to 12 amps total for a 4 wheel setup. If you are not getting that reading there is some electrical issue to deal with, from corroded wires to poor grounds. If you read the full current, then there is probably something wrong with the brake setup itself (shoes, adjustment etc.)


Not sure how you do this. If I pull the trailer plug-in the Prodigy will show 'disconnected'. Are you pulling the brake wire off the back of the 7-way and then checking amps? Just trying to picture how this is done.

Thanks for anymore precise info of how to make these checks!


OK, here you go:

Grasp the trailer cord in your hand with the locater pin at the top. Measure the current from the pin at 11 o'clock to the pin at 7 o'clock.

The 11 o'clock pin will be the +12 volts from the trailer (the charge line) and the 7 o'clock pin will be the line to the brakes.

See photo 1 below. You should measure about 5 to 6 amps for a single axle trailer, and 10 to 12 for a two axle trailer.

Years ago I built an electrical tester with a car end, switches and ammeter, plus fuses all built into one case. You can see it in photo 2 below. In photo 3, you will see that when the Brake switch on the tester is activated, I measure about 6 amps on my single axle trailer.

[Sav'h Steve]

Originally Posted by timmaah

I'm going to put it to the test tomorrow on the 20 miles into Durango. We will see what a little usage does to it. Otherwise I'm stopping at Napa to get some wire.
Thanks all.

I am also wondering how much the usage makes as cwf has said. I did do what he was talking about (getting the brakes good and hot through repeated slowdowns) but it didn't make any difference in my 5 year old brakes ( that MAY have had some grease on the pads-magnet).

Good luck with yours. We are looking to take a 6 week trip very soon and this is slowing us down....

[Sav'h Steve]

Originally Posted by idroba

Need some instruction....
Quote:
OK, here you go:

Grasp the trailer cord in your hand with the locater pin at the top. Measure the current from the pin at 11 o'clock to the pin at 7 o'clock.

The 11 o'clock pin will be the +12 volts from the trailer (the charge line) and the 7 o'clock pin will be the line to the brakes.

See photo 1 below. You should measure about 5 to 6 amps for a single axle trailer, and 10 to 12 for a two axle trailer.

Years ago I built an electrical tester with a car end, switches and ammeter, plus fuses all built into one case.

Thanks for your very quick response!!

That helps explain what I'm looking for. I also assume you are pulling the breakaway cord in order to get the juice going to the brakes. And the cord not being plugged in allows one to check without breaking into the wires.

BTW, that electrical tester is way cool. Think I remember you talking about it before. Any pics from previous posts on how it is wired on the inside?

[GCinSC2]

Iroba

Kudos on the test box.

Gary

[Bob Thompson]

Could it be the design of the controller? My trailer doesn't start braking hard until the truck is doing some serious deceleration, then the trailer adjusts to that deceleration rate. Just a thought. You would need to have the truck hitched to the trailer, going down the road then hit the brakes. As the truck starts to slow, the trailer brakes start kicking in more aggressively. This would prevent unintensional lock-up of the trailer brakes.

[idroba]

Originally Posted by Sav'h Steve

Thanks for your very quick response!!

That helps explain what I'm looking for. I also assume you are pulling the breakaway cord in order to get the juice going to the brakes. And the cord not being plugged in allows one to check without breaking into the wires.

BTW, that electrical tester is way cool. Think I remember you talking about it before. Any pics from previous posts on how it is wired on the inside?

The test that I showed in photo 1 does not require or want the break away switch to be pulled. It takes the +12 volts from the trailer battery (the 11 o'clock terminal) and directly connects it to all the brakes (the 7 o'clock terminal) through the ammeter. That allows you to measure the brake magnet current, which should be 2.5 to 3 amps for each wheel. It also will test the charge line to the trailer through the cord, and the brake line wire through the cord.

I do the testing with the little tester I made a few times a year to check that the brake electrical system is working as it should. One time on a two axle trailer I had I found only 3 amps of current. On investigation, 3 of the 4 lines to the wheel magnets were corroded off , a disaster waiting to happen.

The tester is simple and made up of parts from my junk box. Essentially it is wired this way: The + 12 volts from the 11 o'clock terminal on the "car end" plug was routed through a switch and 20 amp fuse and then through the ammeter shown on the tester. A 12 volt light is also in the circuit, to show me that I have 12 volts at the cord. The second wire from the 12 volt light is connected to the ground line on the cord, which also confirms that the ground line is working.

After the ammeter, a wire goes from each other terminal on the plug, through a switch. Be sure you do not run a switch to the ground terminal! Each switch then will be connected to something, running lights, left brake and turn, right brake and turn, back up lights, and brakes. Label them. Since they all go through the ammeter, you can see, from the tester and the built in meter, that each circuit is taking current. Keeps walking back and forth to a minimum, although the new LED lights take so little current my simple meter does not respond to them. If there is any short, the fuse blows.

I built it about 25 years ago and it has been a valuable tool to test my own trailer and friends and neighbors who come to me with a trailer light or brake issue. It will work on all standard 7 wire hookups which use the conventional pin connections. Now, if the trailer has been wired by someone with the old farmer mentality, all bets are off as to what you may find. That is where the fuse is very handy....LOL.

[Beginner]

First: The long and short shoe must be in the right place.
Second: Voltage does not create magnetic field strength in electromagnets, current does.
First: Determine that the shoes are installed correctly.
Second: Checking the voltage tells you little if you don't know what the current flow is. I have a clamp on DC current meter to dealwith this. If you have a brake electromagnet ( herein reffered to as a magnetic) with a resistance of .5 ohms you should be drawing around 20 amps according to the DC pie chart.(Voltage = Current times Resistance)
If you have measured the resistance of the electromagnets then you will know how much current they should be drawing.
Now, lets say that each electromagnet has a DC resistance of 1 ohm (lets keep the math easy for me).
At that resistance with a voltage of 11 volts each magnetic should be drawing 11 amps.
If you are not drawing 11 amps then you have high resistance in the circuit, probally in the ground side of this circuit.
You have two wires comming from the backing plate. One of them is connected to ground.
Check the voltage on both wires. If you have 11 volts on both wires, you have a bad ground. YOU MUST HAVE A COMPLETE CIRCUIT.
In a perfect world you will have 11 volts on one wire and 0.00 volts on the other wire. In our world you should not have much more than .5 volts.
A lot of people do not look at the ground side of the circuit because no body talks about it much.
Determine which wire is the hot wire to the magnet and which wire is the ground.
A perfect benchmark ground would be to run a # 12 wire (tempory) to the tow vehicle battery and the ground wire of the magnet. With 11 volts at the "hot" side of the magnet and the ground wire running from the tow vehicle battery you will have your 11 amps of current.
I us a clamp on DC amp meter so that I will not have to break any connections to troubleshoot.
If you have any questions feel free to ask.
Beginner
PS. The above post was not there when I started writing my suggestion.

[GCinSC2]

Originally Posted by Bob Thompson

Could it be the design of the controller? My trailer doesn't start braking hard until the truck is doing some serious deceleration, then the trailer adjusts to that deceleration rate. Just a thought. You would need to have the truck hitched to the trailer, going down the road then hit the brakes. As the truck starts to slow, the trailer brakes start kicking in more aggressively. This would prevent unintensional lock-up of the trailer brakes.

Bob,

I think that is the most desirable feature of the Maxbrake, you push and it sends your signal on command. Works for me.

Gary