Gain setting

On my old equipment trailer I had to do two or three stops each morning to get the drum brakes working and even then I wasn't very happy with them. I finally bought a new trailer with electric over hydraulic disk brakes and am much happier with them. They were expensive ($1,700 option) but well worth it on a heavy trailer. Now if they would offer 4 wheel ABS with a better modulation system we could have some real brakes.

Note that friction material has a temp range that they work best at.

Why I test and set the gain when the trailer brakes are warmed up and test them often during the trip. After stopping and they cool down, retest and reset if needed.

The adjustment is something you will do many times as conditions change , low line voltage , corrosion on the multitude of connections in the hundred feet of electric wiring , wear on the brakes , load !

Nobody can tell you what the best setting is because every application is different. Not only that but the "best" setting can change with trailer load, truck load and brake wear. You want to adjust it so that it takes about the same amount of brake pressure to stop the truck with the trailer as it does to stop the truck without the trailer. In other words, the trailer stops itself. Even that is an elusive goal because there is no guarantee that the trailer brakes will behave the same as the truck brakes in a hard stop as they do for a moderate stop. So you basically have to set them for what you are comfortable driving with.

I don't want mine to lock up on asphalt so I generally adjust the gain so that they will just lock up on my gravel driveway. I use the knob on the trailer to test them instead of doing a full panic stop with the truck. That lets me focus more on what the trailer is doing. Most trailers come with daisy chain leaf springs to balance the load on the axles so keep in mind that this setup causes the load to shift from the front axle to the rear during braking events. That in turn leads to the front axle skidding long before the rear one does and leads you to having to make some judgement calls on the brake setting too.

Overall electric drum brakes are much better than no brakes but they are far from perfect and do require more thought in their use. One thing that they are very good for is controlling excessive trailer sway. If your trailer starts swaying too much a quick application of the trailer brakes will generally calm it down. If you find yourself doing this very often you need to work on your hitch setup or trailer loading. I have seen some accidents that could have been prevented with a manual trailer brake application.

Another thing to keep in mind is that some brake controllers disengage at very low speeds. This is fine in most cases and not even noticeable. However, I have had a few cases where I was trying make a sharp turn while going down a hill on gravel or a wet road and suddenly the trailer was pushing the truck the wrong direction. A quick manual application of the trailer brakes got things under control.

A quick summary:
Adjust them to what you are most comfortable driving with.
Be prepared to make manual interventions.
They will never work as well as your vehicle brakes so allow extra room for stops.

That's like asking what's the best Beer. ;)

Yep, trial and error. I've been towing a bunch of different trailers with my Ram and it's interesting how much variation there is for the best setting. Just lots of moving parts (weight, size/condition/ability of trailer brakes, etc.). I was doing some gravel runs recently going between an empty dump trailer (about 2K) and full of gravel (about 10K) and I was going between 2 and 6.

d1h wrote:
Recently bought a Chevy truck with the built in brake control. My question is what is the best setting for the gain? I'm towing a 27ft TT.

No one can answer the question except you.

There are too many variables involved to make it a universal, one answer fits all terrain, all weights, all lengths, all type of loads hauled.

Answering your type of question is also like trying to provide an answer when someone asks "my fuel gauge reads 1/2 tank, how much longer can I drive?"

Start towing. Adjust it until it gives adequate braking for your trailer.

But don't start driving and jam on the brakes so the trailer brakes lock up. That will flat spot your tires. I always start with the setting somewhat low and dial up as needed when I get a new tow vehicle or new trailer.

stickdog wrote:
Good to have an empty parking lot where you can get up to 20mph with gain set at six.
Jam on the brakes if they lockup nock it down a number amd try it again. If they didn't lockup take it up a number.
Whay you want is maximun braking without lockup

Like this. ^

Keep testing till you get it right. Good idea to pull test every time you hook up. Keep in mind that a different trailer will probably have a different gain setting.

Your setting isn't right for me. My setting isn't right for you. Agreed...test it and reset until it works right.

I pull a 10k trailer with the wifes 2016 1500 chevy with built in brake control. I've found 3 to 3.5 gain works great. More gain = brake lockup and flat spotting the tires.
On all my new or used trailers I remove all clam shell type wire connectors and solder those connections. I also add some type of sealant like a 35 year siliconized caulk or a pure silicone/etc in the hole around wiring where it goes into the axle. I then check to make sure their getting proper amps.
I've had trailers that had 12v at the magnets but very little amps....and had poor brakes.