Trailer surge brakes loud banging noises when soft braking

[Husker-Q]

2002 Shorlander for my 18.5 ft Sea Ray

I get a fairly loud and annoying banging sound when the brakes are pressed somewhat lightly. When I do a hard brake, it doesn't do that and I can feel the surge brakes engaged. Interestingly, it does it much more on way home from lake (i.e., wet) than it does on the way to the lake.

I have adjusted the brakes, per instructions, bled the system. One thing I havent done is really figure out if the sound is coming from the brakes or at the tongue area, so need to do that.

Any first thoughts on what to look for next??

 

[Tagerman]

Re: Trailer surge brakes loud banging noises when soft braking

If the noise is coming from the brakes than the noise is probably the drums being out of round (if they are drum brakes). If you take the drums of try measuring the inside diameter at several points. If the drum is out of round and automotive shop with a brake lathe should be able to turn them back round no problem. If you buy replacement drums stay away from cheap ones because they more often than not are out of round from the factory.

 

[JB]

Re: Trailer surge brakes loud banging noises when soft braking

You may be getting "chatter", in which the light braking of the tow vehicle applies too much trailer brake, Husker. The actuator then slams the brakes off. This repeats.

Chatter is caused when the spring that normally holds the actuator off is too weak. It would operate normally for harder braking.

There should be an adjustment of this spring.

 

[Husker-Q]

Re: Trailer surge brakes loud banging noises when soft braking



Thanks for the info - I'll start by seeing if the actuator spring is adjustable. I know there is a piston in there with a spring, just never looked at it in detail. Not sure if the attachment figure will work, but I have a cutaway diagram of the trailer brake assembly.