Brakes pulsing

[psdxoh]

We are 400 miles from home. The brakes on our 2020 297RSTS consistently grab and release, grab and release, etc about every two seconds. In fact if you just cruise slowly through a parking lot and activate the (2021 Ford F350) brake controller abd hold it, the brake gain display flashes full on, then totally off then totally on and so on. It’s not random timing, it’s consistent. I took it to an RV repair shop that put a tester on the truck 7 pin plug that simulates a trailer. The dash display works properly and you can hear the magnets in the test box activate as expected, along with the brake lights in the test box. There is no pulsing - all is normal. Sounds like a trailer fault but they had no way to look at it for several days.

Called another RV repair place they recommended and they agreed to take a look today. The brakes behave totally normal at any gain setting of 5 or below. But higher than 5 the pulsing happens. When driving, it’s a very hard grab and release - very noticeable. Hooked the truck up to a utility trailer and the brakes worked fine. They cut the wiring to the front axle brakes and the problem remained. They spliced those back and cut the wiring to the rear axle and the problem remained.

The RV repair guys are scratching their heads. Any ideas would be appreciated. Thanks for reading.

[Ynot4me2]

I started getting the same thing when coming to a stop at the end of last season. A couple of weekends ago, I adjusted all 4 brakes but haven't had the time to head out yet.

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[geotex1]

Sounds like your trailer brakes are going to ground/shorting. Check the wiring at the axles, especially the run through the tubes to curbside. Bet you'll find some chaffing.

[powerscol]

We are 400 miles from home. The brakes on our 2020 297RSTS consistently grab and release, grab and release, etc about every two seconds. In fact if you just cruise slowly through a parking lot and activate the (2021 Ford F350) brake controller abd hold it, the brake gain display flashes full on, then totally off then totally on and so on. It’s not random timing, it’s consistent. I took it to an RV repair shop that put a tester on the truck 7 pin plug that simulates a trailer. The dash display works properly and you can hear the magnets in the test box activate as expected, along with the brake lights in the test box. There is no pulsing - all is normal. Sounds like a trailer fault but they had no way to look at it for several days.

Called another RV repair place they recommended and they agreed to take a look today. The brakes behave totally normal at any gain setting of 5 or below. But higher than 5 the pulsing happens. When driving, it’s a very hard grab and release - very noticeable. Hooked the truck up to a utility trailer and the brakes worked fine. They cut the wiring to the front axle brakes and the problem remained. They spliced those back and cut the wiring to the rear axle and the problem remained.

The RV repair guys are scratching their heads. Any ideas would be appreciated. Thanks for reading.

What is the computer setting on your brake controller. Us your Truck on board computer to check using your dash display. You may have the wrong setting selected. You vehicle owners manual should able to help. I'm guessing you have electric/hydraulic selected.