View Full Version : Surge Brakes not Releasing

07-14-2013, 09:57 AM
After doing a total brake system overhaul on the trailer, I am having trouble with the brake shoes not releasing all the way.

The trailer has a new UFP actuator and four new backing plates will all new shoes and springs. I replaced all the parts, bled the brake lines out, then adjusted the shoes so that they were just barely off the drum when the wheel cylinder was retracted.

Everything seemed fine, so I went on about a 20 mile trip and noticed the hubs seemed a little warm, but just figured it was because of the stop and go traffic. Went home put it in the barn for a few days then last night I went to pull the boat out and noticed it felt like the brakes were holding, so I put a jack underneath a wheel and tried to spin it by hand, long story short all four wheel had a significant amount of brake pressure applied, and this is with the tongue actuator fully extended.

So I pulled the drum off one and sure enough the wheel cylinder would not retract. I had to crack the bleeder on the wheel cylinder in order for it to release, once I did that, all four wheels turned normal.

What could have caused this? I will be towing the boat 300 miles in 6 days, and I need to have this resolved.

Thanks in advance,

07-14-2013, 10:05 AM
could need an adjustment on the brakes... there should be just a minimal drag on wheel when actuator is in fully extended position.

I had lockup problems do to drums being out of round.

It's possible water got into the wheel cylinder. - You can order full backing plates for about $50 from e-trailer.com, pacific trailer.com - e-trailer is in St. Louis so you could get the parts fast.. plus they are open on Sunday.

07-14-2013, 04:35 PM
It has brand new backing plates that come pre-loaded with all components and a new master cylinder actuator in the tongue. It was as if brake hydraulic pressure was applied and then was not able to release. I know this is not the case, but it is as if the system has a check valave on the brake line, fluid pressure goes out but does not release.

I am not 100% sure (it has been several months since I installed them. but I think these are the replacement parts we ordered.



07-14-2013, 08:09 PM
Since all wheels returned to normal when you used the bleeder seems to indicated pressure is not being released. Try the trouble shooting procedures in the UPF mantenance manaual - http://www.ufpnet.com/Portals/0/PDFs/A-60,%2075%20_%2084%20Actuator%20Maintenance.pdf. There is a procedure on page 19 to test/isolate if it is the actuator.

Your breakaway cable has not been release has it?

07-14-2013, 09:00 PM
There is a tab underneath the actuator that should be pressed according to the manual

It releases the pressure...

Just a thought.

07-14-2013, 11:37 PM
Page 7 under Breakaway Cable of that manual:

...Inadvertent setting of the brakes by pulling the
breakaway cable is the single most common mistake users make... To retract the breakaway cable, slide the coupler fully forward and push up on the pushrod release bracket located on the underside and behind the hitch ball socket to allow the bead to retract into the actuator. This will release the trailer brakes. Install new clip on breakaway cable in front of bead...If pushing up on the bracket dose not release the brakes or if it is hard to push, insert a pry bar into the 5/16” hole behind the bracket. Use pry bar to stroke push rod backwards to relieve load on bracket. Push up on bracket and hold up while releasing pry bar. The pushrod release bracket should now move freely and brakes should be released. (figure 7) Check to see if the actuator is reset. Extend the actuator fully. Remove the cap from the top of the actuator and pull the plug from top of the reservoir cover. While looking at fluid in the reservoir, manually compress actuator. In the first 1/8” of coupler movement the fluid in the reservoir should “splash” or “ripple” slightly. If it does, the actuator is working properly...

Mark rsa2au
07-15-2013, 12:17 AM
Same problem with mine! Was the break away cable.....

Have now cut it off as it serves no purpose other than to get tangled and cause problems like overheated brakes and bearings, themselves a safety concern. If the trailer should come off the tow ball.... (never had this in 20 years, but there is always a first).... and if the trailer should break BOTH safety chains each rated at 2 ton. Then what ever caused that situation probably means the trailing brake effect caused by the breakaway cable will have no effect...

07-15-2013, 07:45 AM
I will go back and double check the emergency cable, but hopefully I have resolved the problem.

I was doing some fairly extensive reading and I came across similar problems when the Brake system was not completely bled of all air. So I made sure to jack it up to that the actuator was significantly lower than the wheel cylinders, and went through the whole process of bleeding the system again. Took it for a test drive and seemed to be working properly now, but it was a very short drive, so time will tell.

Thanks for all the help!

07-15-2013, 07:51 AM
Actually lost a trailer after not putting in the safety pin that held the latch down on an Easy Loader trailer for a Sea Ray I had. Went through a series of dips and on the last one the trailer popped off the ball. I had the chains crossed which stopped the tongue from hitting the pavement and the break away cable actually worked and set the brakes on the trailer. Was only going about 35 MPH and it made one heck of a noise but other than braking the cable nothing else was damaged. I loaded back up, released the safety and continued on to the ramp. After that little episode I've made sure that cable is there and that it's working correctly. I also believe it's required or at least it is in Michigan and with the way people litigate things these days I certainly wouldn't want to have it removed then be in some kind of accident/injury incident.

That being said I've seen set ups where the cable is too short for the tow rig and caused problems. I've also seen where people have forgotten to disconnect the cable and have had issues.

07-15-2013, 10:57 AM
I just overhauled my drum brake and actuator system as well and have bled the heck out of it and I think there is still air in it. Using a prybar and manually engaging the actuator I have to push the actuator back almost all the way for it to engage the brakes...? Can't figure it out. Shoes are adjusted properly and I resurfaced the drums, so I know they are round.

07-15-2013, 12:09 PM
Using a prybar and manually engaging the actuator I have to push the actuator back almost all the way for it to engage the brakes...? Can't figure it out. Shoes are adjusted properly and I resurfaced the drums, so I know they are round.

I had this very same problem just last night. Adjusting procedure for brakes is to adjust shoes out until you can barely turn the tires forward with two arms and some muscle. then back off 8-10 clicks on the adjusting wheel.

After I did this I noticed that when applying brake pressure with a pry bar it would barely grab at all, so I put both axles up on jack stands and hooked the trailer up and applied pressure like it would when towing. (backed the truck hard against the trailer) after doing this all four wheels were tight and I could not turn them.

Somehow more pressure/plunger displacement is achieved using the actuator as it would be used when towing.

07-15-2013, 04:04 PM
I replaced the backing plates on my 95 Maristar trailer and had issues getting the brakes adjusted. Mine seemed like the backing plates were not centered. If I adjusted them back to the point where the wouldn't dragged they barely worked. If I set them so they would work they would end up dragging and heating up the axel.

After a couple weeks banging my head against the wall trying to figure what was wrong I finally bit the bullet and converted to disc, never had a problem after that. Some things are just to complicated to spend too much time on when the best answer is staring you in the face. I know tossing those somewhat expensive new parts is not fun but losing a wheel on your trailer while taking a trip is going to cost you a lot more in the long run. Dealing with your wife and kids while on the side of the road will also be priceless. If you do decide to go with a disc conversion you won't regret it.

07-15-2013, 04:15 PM
The new backing plates have a reverse helper - the brake shoe mechanism floats a bit on the backing plate - If the drum is out of round it can lock up cuz as soon as the shoe touches the drum it will try shift and try to lock.

I also had an issue with the brake locking up after launching boat and boating all day. moisture on the brake pads can cause them to grab onto drum.

when I use my custom "C" clamp for the reverse lockout I have no problems.

TO bleed the brakes well - use a ratchet strap to full press the actuator in. leave actuator in full position - open bleeder close bleeder. repeat till all air gone.

The stupid screwdriver method drove me crazy..... need to keep constant pressure to bleed properly... until I used the ratchet strap I always had minor issues....now I have none.