Trailer brake evaluation

[JRS]

I have a 32 foot Mainliner enclosed race car trailer with dual axles. Compared to the other three, the left front brake does the lion share of the work. (based on drum temperature) I have tried new brake assemblies (all four corners) and of course adjusting the star wheels. This has taken care of some of the problem, but a small percentage. I am now thinking that my problem is electrical related. Can I simply apply the truck brake with a broom stick, while parked in the driveway, and check the voltage at each of the four trailer brakes? Should I borrow a tracer and trace the wiring? Possible bad ground? Everything else electrical works fine on the trailer. (lights, battery charging, turn indicators, etc. )

 

[JHardwick]

Sometimes it's just the way the wiring is routed. Let me guess, the brake wire runs down the left side and to the LF first, right? My thought is that each brake wire should be the same length after the split of the main run from the truck.

Or, it could be a corroded connection as well.

 

[JRS]

Hey, thanks for the heads up on the corroded connection. Now that I look at it, there are several of those Scoth-loc tap connectors installed by the previous owner. Those were probably installed 5 years ago or more. They weren't wrapped with tape or sealed, so I would imagine they have corroded by now, exposed to road moisture/dirt/dust.

 

[Cattletrkr]

Yep, connections like that only last so long. Check your grounds too. I prefer each wheel to have its own ground.

 

[Hoefler]

To fix the same problem on my enclosed trailer, I rewired it from the pig tail back with 2 12ga wires, one to each side and them soldered and heat shrink-ed the connections. Also like said above I grounded each wheel to the frame and ran a 12ga wire back to the pig tail. I also found a pig tail that has a 10ga wire for the ground, hot lead, and brakes. All connections were soldered and heat shrink-ed. Another note, do not run the wires through the axle tube, they will rub bare, become corroded ,and short out.

 

[Sean Woodruff]

If it is wired like a travel trailer, and it sounds like it is, the left front brake is the first one to get the wire.



If you wire back to a junction box between the axles and then run an equal length of wire to each brake you'll notice a huge difference in your braking.

 

[steved]

If the wire is of sufficient gauge, location along the length should not matter.



What I have found, to affect the brakes more than wire size, is those blasted scotch-loc connectors they insist on using... they don't get a very good connection when installed, and it only gets worse with time (corrosion). I typically remove these and solder every connection (I like sure connections)... never have an issue.

 

[JHardwick]

My thought is that each brake wire should be the same length after the split of the main run from the truck.

If you wire back to a junction box between the axles and then run an equal length of wire to each brake you'll notice a huge difference in your braking.

I agree :-laf



The extra grounding should help as well.



I'm a solder/heat shrink type of guy, and this 4-Star of mine was soldered from the factory, unlike a lot of trailer manufacturers. However, I've seen a lot of connections fail between the solder and the insulation on the bare copper wire. I have to go over mine every spring from the winter chemicals.

 

[jelag]

We've had problems with the stock wires going through the axle tube from one side to the other... as the trailer runs down the road the wire can rub in the axle and wear. . causing shorts and opens...

We finally removed all the wires... and rewired with butt connectors that are un insulated and shrink tubing like what is used on well casings... it has an adhesive in the shrink tube so as you heat it and shrink it, the adhesive melts and seals to the connector and wire making a water tight connection.....

Since this has worked so well for us... we've quit using the insulated butt connectors and only use the shrink tube...

 

[JRS]

I agree with the shrink-fit sleeves with adhesive. Fasten-al down the street sells them. I really belive my problem is going to be the 3M connnectors. They're great in an emergency, but not for long term. Since it's a used trailer, I can only imagine that the trailer store that changed out the axles is the ones that installed the 3M connectors.



Believe it or not, I've had really good luck sealing up wiring connectors with a product called Shoe-Goo.