Need Help! Screwy Surge Brakes?

[NiceAft]

Maybe someone out there in MacGregor land can figure this one out.

Today I went fishing off the coast of Atlantic City. I drove 70 miles to the shore, backed the trailer down the ramp twice (once in, once out), made a u-turn which meant I had to back up at least once, and went home. When I got to my house, I could not back up the street into my driveway without the surge brakes engaging. Every time I tried to back up the street (hill) to get to my driveway, the brakes engaged. My street is definitely a hill. I drove around the block and came in from the other direction ( backing down the street [hill]). It worked, but when the trailer wheels started going up the apron of the driveway (small upward incline) the surge brakes engaged again? I finally had to give up and drop the trailer curbside. The problem was only happening when I tried to back up a hill.

The wire on the harness that connects to the electrical override for the surge brakes was cut twice in the last month, and I spliced them together. I know it works since I made several back-ups with the boat today.

Anybody know what's going on?????

[Night Sailor]

Surge brakes work that way when they are working properly. Backing up a steep hill puts the weight of the trailer pushing forward against the hitch just as it does when you put on brakes and the vehicle slows before the trailer, allowing the trailer to "surge" forward.

You can stick a thick screw driver or wood dowel in the slot between hitch and surge unit, to prevent it from going foward while you back up hill. There are also commercial things to buy that allow you to do the same thing. Just don't foreget to reset the trailer to normal condition after you back uphill and park it.

[NiceAft]

Night Sailor,

Thanks for your reply, but I'm not sure you are correct. If you are, then it implies that the brakes have not been working properly since I got the Mac.

The electronic override does just that, override the surge brakes when you go backwards. Why are they now engaging in reverse only when I back up a hill?

[RobertKing]

My surge brakes acted the same way, on level it would back up as long as you didnt start quick, however I could not back up the slightest grade. I used a meter and found the bad connection for the electronic lockout relay. Until I found the problem I had a little "key" that I could put in the slot and disable the surge brakes. Another thing to check is it also could be possibly the fuse, probably on the same circuit as your backup lights.

[Duane Dunn, Allegro]

Clearly your electronic lockout is not working at all. You don't notice it backing down hill because the hitch never compresses the piston applying the brakes. If you accelerated fast enough downhill they would most likely engage as well.

Either your trucks backup circuit is not working (do you get backup lights?), the wiring from the truck to the trailer is not good, or your lockout valve is not functioning. When the valve receives electricity it closes preventing any brake fluid from being pumped into the lines to engage the brakes.

My first guess would be the wiring. The valves are pretty reliable. Are your trailer lights working? In my experience half the time electrical problems with boat trailers are not the positive wire, but the ground wire. Check that as well.

You can always prevent the slide from moving by placing an object in it's path. Usually there is a loop of metal through which you can place a large screwdriver or some other object to stop it sliding. Usually the same pin that holds the removable jack wheel on will work. Before I switched my X brakes to discs and added a valve I actually drilled a hole through the slide and the hitch low on one side that I could just stick a pin in. It is nice to now have the lockout provided I can keep the electrical part working, but in a pinch I can always go back to the pin.

[NiceAft]

Thanks for the info guy's,

I'm going to check out if there is any electrical power going out when I put the truck in reverse.

Robert, your problem sounds exactly like mine. I'm going to check it out.


Ray

[Frank C]

Ray, I have recently added the UFP actuator to control my new Kodiak discs. (UFP is the same actuator that Roger now puts on the 26M, come from the mfg with the relief valve installed.)

Anyway, my saddle-time is still limited, but I found the same problem a couple of times. I found it worked okay if I just waited a few seconds after engaging reverse gear (and brake lights), but before beginning to move the rig. This is like Robert's report, but mine WAS able to back uphill after pausing for a slight delay. Upon reflecting, I guessed that the relief valve needs a slight delay to actually relieve the system pressure - I know that seems contradictory for a braking system ... but it worked twice so far.

[baldbaby2000]

If you put your ear to the tongue near the surge brake cylinder and have someone put it into reverse, you should hear a click as the solenoid engages. Or you can have the truck in reverse and plug and unplug the connector and listen for the click. If you don't hear that click, you probably have a wiring problem. Do the lights work? If not there may be a ground problem. Put a meter on the wire and see if it goes to +12V when you put it in reverse.

[Chip Hindes]

I guessed that the relief valve needs a slight delay to actually relieve the system pressure - I know that seems contradictory for a braking system ... but it worked twice so far

Can't say why this method is working for you, but it's not the reason you stated. The system doesn't work by relieving pressure, it works by blocking pressure going from the master cylinder to the brake cylinders.

If the solenoid isn't working, you will not be able to back at all, including when on a level. BTDT. Check it the way bald suggests; put the tow vehicle in reverse (engine off, of course) then plug and unplug the harness. You can easily hear the solenoid clicking if it's getting power.

There is a special problem with backing on a hill. If you stop on the hill with the tongue compressed, the master cylinder will be energized, with pressure to the brakes. Then when you put it in reverse, you are simply locking out the system with the pressure already "on" and will not be able to back up. A manual, pin type lockout will work, you only have to remember to pull the pin when you get done so the brakes will work properly. Also, you have to make sure the tongue is extended or you won;t be able to get the pin in.

The manual also suggests that you can block the trailer wheels, then allow the tow vehicle to coast forward slightly before shifting into reverse. This allows the tongue to extend and the pressure to be relieved; then the lockout solenoid can function in the normal manner. I've never had the need to try this, but it seems as if it should work.

[Frank C]

I guessed that the relief valve needs a slight delay to actually relieve the system pressure - I know that seems contradictory for a braking system ... but it worked twice so far

Can't say why this method is working for you, but it's not the reason you stated. The system doesn't work by relieving pressure, it works by blocking pressure going from the master cylinder to the brake cylinders.

Actually, it's not always true that the system works by blocking pressure to the brake cylinders. There are two different styles of backup solenoids, those that are "normally open," versus the "normally closed" valves as used in UFP actuators. Champion offers both alternatives.

Normally closed ("bleed-type"): requires a short brake line plumbed back into the master cylinder. When this valve opens it shunts fluid back into the master cylinder, nullifying the brake line pressure. It's better because it permits backing uphill without special precautions, but it also requires plumbing the return line.

I chose the UFP actuator for my 26X trailer upgrade. They include a bleed-type solenoid embedded within their disc brake actuator. This is the same (A-60) actuator that is listed on Macgregor's vendor parts list, so it is standard issue with the 26M trailers.

Normally Open ("blocking-type"): works by blocking brake line pressure as soon as the brake light circuit energizes the solenoid. This style is common in retrofit packages because it's more simple to plumb it into the brake line just after the master cylinder. It's drawback is described by Champion as follows:

Blocking solenoid valves are very effective and are used on many disc brake applications, however if you attempt to back up, in an uphill configuration, it may occur that you will have a partial activation of the surge brake coupler due to the compressive forces being applied between the tow vehicle and the trailer, prior to backing up. This may drastically impede your ability to back up the hill.

If this occurs you may want to convert your reversing solenoid to a bleed type solenoid valve. With a bleed type solenoid valve, whenever the solenoid is activated, all fluid pressure in the system is dumped back to the reservoir. This is the preferred solenoid valve if backing uphill is one of your towing considerations.

However, the bleed type solenoid [part # 1504] requires that a return line be installed back to the brake coupler master cylinder reservoir.

[Frank C]

BoneHead Backup

Last Friday I entertained some associates from Tokyo with "a day on the Bay" but my inauspicious start was very embarrassing. I fully understood these trailer brake differences, but I was completely puzzled - by my own bonehead move.

Hooking up to the dry-stored boat was part of the "education" for these guys and it went well. After towing the short, few hundred yards to the ramp, I simply COULD NOT get the trailer to back up, even though I had verified the backup lamps were working. But no combo of steps would enable the disc trailer brakes to release and let the boat down the ramp.

Two other boaters were in the next lane, and I commented to them how foolish I must appear ... explaining the the trailer's brakes just wouldn't release. Then one of them was kind enough to take a look, and remind me that I had not attached the wiring umbilical from truck to trailer!!

The rest of the day went very well, motoring to the SF cityfront, snapping lots of pix, hoisting sail and sailing upwind for awhile, around to the lee of Clipper Cove for a lunch stop on the Bulwagga. My friends from Japan were duly impressed by the 26X, if not by the Skipper!

Lesson: both types of solenoid must be connected to the tow vehicle or they won't work! Before upgrading to the disc trailer brakes, my practice was always to disconnect wiring to the tow vehicle to hopefully avoid any shorting that could blow a fuse. Further, when I tow the few hundred yards to my ramp, I'm not actually driving on city streets, so wiring was clearly optional ... no longer optional!

[Duane Dunn, Allegro]

I had the exact same issue earlier this week. The boat was parked in the driveway after last weekends trip.

After powerwashing it to remove the salt I hitched up the truck for the 35' trip back into our covered storage area, no need for those chains or wires. As I'm backing up into the I couldn't get the thing to go the last 3' which is slightly up hill. What's the deal, am I hitting something? I pull forward, same problem the second time. What's that sound, is it the brakes groaning. Then I notice the trailer cables and realize the issue. I plug in the extra 5th wire for the solenoid I added. Still doesn't work. Silly me, I have to hook up the other plug to get the ground. Darn, brakes are still on. Oh wait, the solenoid is now closed with the tounge compressed trapping the pressure. Shift into forward, pull out 3', then finally it backs in smoothly.

Some of us learn these things the hard way. At least only my wife was watching my stupidity, nothing new for her.