Surge brakes releasing

[skydiveD30571]

2007 Tandem axle EZ-Loader trailer with surge drum brakes on rear axle. Stopping at a light seems normal to me. But as I let off the brakes and start to accelerate, it feels like the truck moves while the trailer sits still for a fraction of a second, then it catches and shakes the truck front to back for a second or two, then everything is rolling as it should. When I first got the boat I was told that it is fine, it's just the trailer tongue extending back to normal and releasing the surge brakes. However, talking to other people who rode with me recently that have experience on other similar trailers, they say that is not normal and it shouldn't be so rough coming off of the line. Anyone seen this before?

 

[UncleWillie]

Re: Surge brakes releasing

Make sure you are not low on brake fluid causing the piston to compress way more than necessary and therefore taking longer to catch up.

Many actuators have a spring in the actuator to push the piston back out once you stop so there is no catching up to do.
Is the spring good?
Is the Actuator binding?
Have you Oiled the slides lately?

 

[tpenfield]

Re: Surge brakes releasing

As my trailer with surge brake coupler aged it go more sloppy, so it would give me the sensation that you described. As long as the boat and trailer were still there each time I looked in the rear view mirror, I did not worry too much about it. Just kept it in mind as I started off from a traffic light, etc.

The coupler had some grease fittings, so I would pump those up occasionally, did not make too much difference. At some point, I figured on needing a new coupler, but then I sold the boat & trailer.

 

[lncoop]

Re: Surge brakes releasing

It is normal to feel the actuator extend, but the process definitely should not shake the tow vehicle. Something is amiss. I'm with Willie that the first step should be to check the fluid level in the reservoir. If it's low find and address the leak then refill and bleed. This should be considered periodic maintenance anyway, so it won't be a waste of time. If that isn't the problem check the other stuff.

 

[frantically relaxing]

Re: Surge brakes releasing

I don't know how all surge brake activators work, but some have roller bushings like in the pic below- When they're nice & round the activator will slide back and forth quickly and effortlessly, and that's when you don't notice anything. But when they start to hang and quit rolling and end up looking like those on the right, regardless of whether you have plenty of fluid and return springs, the activator ain't going nowhere till the truck moves, and then it's sudden and usually with a BANG. Pull the cover off the activator and see what makes it tick-- you might find the problem! (had a machinist friend make the new ones for me)

 

[Thalasso]

Re: Surge brakes releasing

The main cause for brake actuator to release like that is the brakes need adjusted. There is to much travel in the actuator

 

[04fxdwgi]

Re: Surge brakes releasing

Had the same problem on my trailer, which was 20 years old. Had drums on one axle only. Adjusting the brakes and bleeding helped tons, but didn't eliminate the BANG on the start from a dead stop..

Then I did the big conversion to discs. When I replaced my single axle drums w/ tandem axle Kodiac Discs, I also replaced the master (needed to w/ the conversion) and all flex lines were converted to S/S units. I also completely rebuilt the actuator w/ new plastic bushings (they call em bearings) and new shock pistons and cleaned and greased everything properly. The two shock absorbers were totally worn out after 20 years.

Now it's more a mild clunk than a bang, is normal for surge brakes, and is very tolerable. But the stopping power with discs is like night and day.

Maybe next year it'll be an electric over hydraulic conversion for the best of both worlds of electric control with disc brakes.

 

[skydiveD30571]

Re: Surge brakes releasing

The main cause for brake actuator to release like that is the brakes need adjusted. There is to much travel in the actuator

Thanks guys for the inputs. Fluid level is right at the bottom of the plug just as the ez-loader manual says it should be.

As for the brakes adjustments, that's currently in process. Earlier today I jacked up the trailer and the right brake tire spins basically continuously...meaning a simple push and it has no friction at all. Definitely way out of adjustment and explains why I felt like I had to step on the tow vehicle brakes pretty good at highway speeds. If I remember right from last fall season, the other brake wheel is about the same way. I tried adjusting the right brake from behind with a flathead screwdriver but can't get enough leverage because of the leaf springs right there. I'm going to pick up a brake adjustment tool on my way home and try again. Worst case I can pull the wheel and shoe and adjust it that way.

UncleWillie (or anyone else who knows), in regards to oiling the slides, the manual mentions it but the sketched pictures are anything but understandable. Can someone clarify as to where I should focus? I'm guessing it's around where the coupler goes into the tongue. And what kind of oil are we talking here?

 

[UncleWillie]

Re: Surge brakes releasing

Oil it where you see the Pins sticking out the side and anywhere else metal slides on metal.
Lay under it and look up; the contact locations should be obvious.

The coupler should return to full extension in the first inch after taking your foot off the brakes.
Your speed should still be low enough that the CLUNK is minimal.

 

[Thalasso]

Re: Surge brakes releasing

When you adjust the brakes and spin tire to check drag, make sure you spin it as if the tire was rolling forward

What brand/model of actuator do you have that needs lubed?
Some types of actuators have a grease fitting on the end of the bolts that get greased

 

[skydiveD30571]

Re: Surge brakes releasing

Well I adjusted both tires so that they have enough contact to make 1-1.5 revolutions when spun by hand (found that in another forum about drum brakes). They both would spin freely before. I also oiled all around the coupler. Ill find out friday if any of this helps the clunking. Atleast ill get some trailer braking now!

 

[agallant80]

Re: Surge brakes releasing

My new trailer with surge breaks does the same thing. I think some of it may be due to the hitch pin not being tight on the recieaver and it clunking when I pull away. Never put much thought in to it.

 

[skydiveD30571]

Re: Surge brakes releasing

EZ-Loader says some clunk is normal, as have the guys in this thread. But mine was to the point that if you simply let off the brake completely and let the truck idle forward, no gas pedal, it would jerk so hard the truck would shake and oscillate back and forth.

 

[UncleWillie]

Re: Surge brakes releasing

EZ-Loader says some clunk is normal, as have the guys in this thread. But mine was to the point that if you simply let off the brake completely and let the truck idle forward, no gas pedal, it would jerk so hard the truck would shake and oscillate back and forth.

Are you certain the Clunk is coming from the Actuator?

Stand on the side of the trailer with someone else driving.
Stop briskly to compress the Actuator. It should only move about halfway back in the slots.
Idle forward. Watch to see if the Clunk is coming from somewhere else other than the Actuator.
The Tongue, or the Axle Springs Hangers, or something else may be moving.
From the drivers seat, you can't tell much more than it is coming from somewhere in the trailer.

 

[04fxdwgi]

Re: Surge brakes releasing

"Stand on the side of the trailer with someone else driving." Really??????

 

[skydiveD30571]

Re: Surge brakes releasing

"Stand on the side of the trailer with someone else driving." Really??????

I think you read too far into that. I took it as "stand to the side of the trailer so you can see it."

Willie, I'm not sure if it's coming from the actuator or not. After checking fuid levels, adjusting the brakes, and oiling the coupler, I'll be trailering this evening and will see what improvements were made and go from there. If it still does it, I'll take your advice and zone in on where the sound is coming from.

 

[UncleWillie]

Re: Surge brakes releasing

I think you read too far into that. I took it as "stand to the side of the trailer so you can see it."

This is what makes english so much fun! :lol:

Yes, Stand TO the side.
Or stand ON the side, at a safe distance.

Consider if someone said, "The kids are outside playing in the grass on the side of the house.";
Does that mean the house has grass growing on the side wall and the kids are climbing the walls?
I wish I could draw, that would make a great visual! :joyous:

 

[DABS]

Re: Surge brakes releasing

You most likely have a UFP actuator. The "clunking" you describe, usually will go away with proper bleeding of the system. The shock inside the actuator is a dampner type shock not a gas shock. If you do not have the manual for the actuator you can go to UFP > Home and click on actuators, then download the pdf file for the A-60, A-75, & A-84 model. Only the nose piece is different in the 3 models. The master cylinder is the same on all UFP actuators. Look on page 25 -27 for bleeding instuctions. Remember, air bubbles travel up in fluid so before bleeding your brakes, lower the nose of the trailer to facilitate the bleeding process. Any air in the system will travel naturally toward the highest point now, the bleeders. Follow the bleeding instructions and test when complete by disconnecting the electrical plug and trying to back up a slight incline. The brakes should fully engage and the forward pin on the side of your actuator should be 1/2 to 3/4 of the way back in the travel slot. Any further would indicate the presence of more air in the system. Check your lines carefully for leaks. Where fluid leaks out, air is replaced. Any air in the master cylinder will again cause the clunking. If you have any further questions you can call 1-800-835-9211 ext 16 or email warrantytn@ufpnet.com .

 

[skydiveD30571]

Re: Surge brakes releasing

Adjusting the brakes seemed to help a great deal. Not only do I have noticeable stopping power, but the clunking noise has basically disappeared. Towing in town I felt a very small bump right at brake release, small enough to not notice unless you were trying to notice it. At highway speeds there was also very little unless I rapidly stopped like at a toll booth. Even then, it is moderate and much better than previously. Thanks for the comments everyone.