Will Trailer Surge Brakes Apply When Travelling Down Hill

Updated 06/17/2026 | Published 10/02/2024

Question:

Do hydraulic brakes drag all the way down a hill? It seems like this will cause them to overheat.

asked by: Kevin C

Expert Reply:

Hey Kevin, this is a great question but basically it would take more force than cruising down a hill for the surge brake actuator to apply the trailer's brakes. Basically it would take you applying the trailer brakes down the hill. The great thing about surge brakes is that if for some reason the trailer brakes end up applying to hard it would pull the trailer back from the tow vehicle which would stop the braking action.

The only time there's a real issue is backing up the trailer up a hill. But in those situations there are reverse lock outs and free backing plate brake assemblies to combat that.

expert reply by: Jameson C

Jameson C.

12/22/2025

Hey Kevin, how did things go with your surge brake actuator on those downhill runs? Did the braking feel smooth without any drag or overheating? Your feedback could really help others wondering about the same setup.

Daryl

6/17/2026

I have found it on long downhill grade, the trailer Blakes will apply lightly but not enough to pull back on the tow vehicle which causes the brakes to overheat by the time we get to the bottom of the hill.

Jameson C.

6/17/2026

@Daryl that's what most will report. If the brakes were to somehow apply to hard it would pull the trailer back and release the brakes basically immediately.