troubled surge brakes: diagnosis and repair tips???

[silkefelix]

Hello all,

We recently bought a MacGregor 26M from 2004. When we got the boat, the surge brakes on the trailer still worked, now they don't. After talking to others, we figured out that the most likely reason why they broke was that my husband backed up the trailer without unplugging the electric trailer harness from the car. Apparently the trailer wheels locked when backing up and then there was a popping noise. From then on the surge brakes did not work. Since we are soon going to trailer our boat from Florida to Alaska, we need working brakes. My husband checked the brake fluid level and the lines. Both seem ok (no leaks). Any ideas what could be the problem and whether my husband as a pretty handy person could fix that himself?

Thanks for any feedback, Regards, Silke & Felix

[Captain Steve]

Happened to me and others here on the board. The linings separate from the brake shoes and jam up against the drum. Usually due to rusted out rivets that hold the lining on the brake shoes. You can free them by removing the rim and then the drum. All the parts should fall out. I upgraded to stainless steel discs. this is also covered in the archives. If the rest of the assembly is not too rusted, you will need new brake shoes, readily available at an auto parts place...they are a common size. Better service or replace the bearings before the trip too....low cost about 30 bucks as I recall for new pregreased set at the auto parts place.

When I tow I cary a grease gun as well as a spare set of bearings. Keep them greased so they keep cool.

Can someone help with a search for bearings and brakes??

[kmclemore]

Answers to this have been posted many times here on the forum, but here's a good one on the bearings:

http://www.macgregorsailors.com/forum/v ... =11&t=9872

... and here's one on seized trailer brakes:

http://www.macgregorsailors.com/forum/v ... 11&t=11827

Regarding all things 'trailer', I suspect this website may be of good use to your 'handy husband':

http://www.championtrailers.com/techsup.html#TOP

And finally, there is this useful warning to all of us:

Brake Coupler Trailer Parking Warning !!

When parking a trailer EQUIPPED with HYDRAULIC SURGE BRAKES it is important to be sure that the BRAKE COUPLER is pulled back forward to the fully telescoped [ TOWING ] position prior to final disconnecting of the trailer from the tow vehicle.

[ 1 ] Any HYDRAULIC BRAKE COUPLER that has a cast iron master cylinder, and is left with the brake coupler partially, or fully compressed [ as it would be when backing up ], will have part of the interior of the cast iron master cylinder wall exposed to the atmosphere.

Many times this will result in corrosion of the exposed cast iron cylinder wall, and will result in the fact that the piston in the master cylinder will not extend back to it's normal towing position the next time the trailer is towed.

This will result in hydraulic pressure being maintained on the trailer brakes, while towing, and will probably result in damage to the trailer braking system. This could result in a catastrophic accident !!

This phenomenon does not normally occur in brake couplers with COMPOSITE or ALUMINUM master cylinders, however it is a good policy to be sure that the brake coupler is fully extended to the towing position prior to disconnecting the trailer from the tow vehicle.

[ 2 ] A second reason to be sure that the brake coupler is fully extended to the towing position is that if hydraulic pressure is left on the trailer brakes while parked, the brakes shoes of a drum brake system, or the brake pads of a disc brake system will be maintained in FULL contact with the brake drum, or rotor. Many times this will result in the bonding [ sticking ] of the shoes or pads to the co-ordinate braking surface.

This will often result in a trailer that has the brakes locked up when the tow vehicle is attached. Sometimes jerking the trailer forwards, and backwards is enough to break the corrosion bond that has developed however sometimes the brakes must be disassembled to relieve the problem.

[ 3 ] SAFETY FIRST --- BE SURE THE BRAKE COUPLER IS FULLY EXTENDED BEFORE DISCONNECTING FROM THE TOW VEHICLE.

[socalmacer]

Backing up with surge brakes, non-disc brakes in my experience is usually not the problem or cause. They don't grab like disc and as such you can back up without having to "block" the master cylinder. Salt water/rust, as already mentioned is the usual culprit. For the quickest fix, you may consider replacing the drum brakes with a new set of brakes that are galvanized. They are a standard size and be purchased from most trailer parts stores. Automotive parts stores will not have galvanized in my experience. These will give you a few years of service and may save some money over the stainless. You can add to the service life by putting a fresh water rinse kit, which if you use after every salt water dunking will extend the life further. Ultimately stainless is the way to go. Don't buy the China crap as you will get what you pay for. I did and ended up having to customize them to fit. Noter you will have to replace the master cylinder when doing the disc conversion and I would suggest doing the brakelines at the same time. If you've never worked on brakes before, I might not suggest starting now. Before considering replacing the brakes and the expense, you may want to survey the entire trailer inside and make sure it's not a rust bucket. I got a year's worth of service out of my stainless disc brakes only because the rest of the trailer rusted away! Anyway, good luck!

[silkefelix]

Thanks for your responses, everyone! I checked out the links. Our problem is the opposite as most described in the forum. The brakes are not locked in position, and my husband did not have a problem opening them. When we use the trailer, the brakes do not engage although there is enough brake fluid and no leaks in the lines. The brake pad and discs are in good condition. The problem we have now is that the brakes on our Toyota Tundra start to warp because they take the full brake force. Any ideas on what could be going on here? Regards, Silke & Felix

[Terry]

Curious problem....I am not that mechanically inclined to diagnose your problem but I can share some of my problems with an older trailer. You have a 2004 trailer??? I have a 2003 26M trailer, it has a pin that you have to put in place to back up because mine is only a four wire harness. I also have the six lug nuts, larger wheel and 5000# capacity trailer so it is an older one. I put the pin in to stop the surge from engaging when I back up, sometimes I forget to take it out and drive away without the surge brakes functioning but I notice it pretty fast. I don't know if the '04 trailer has 5 wire harness or 4 but the 4 wire uses the pin whereas the 5 may not. Mine are also rusted considerably, I changed the worn brake pads myself with instruction from my neighbor and got them working some years back but the rotars are still rusty. I am not sure they even still work I have to check this spring before I haul the boat out, for now the trailer sits empty in my driveway. It needs some work. I only have to tow a short distance to the marina so it is not that critical but I'd still like to keep the trailer in good order, never know if/when I may sell my boat & trailer. I also backed up with the electrical harness connected and into the drink but the lights still work and only so far have rusted out nuts & bolts on the lights. I think I will get those truck lights scott posted about.

[MadMacX]

Thanks for your responses, everyone! I checked out the links. Our problem is the opposite as most described in the forum. The brakes are not locked in position, and my husband did not have a problem opening them. When we use the trailer, the brakes do not engage although there is enough brake fluid and no leaks in the lines. The brake pad and discs are in good condition. The problem we have now is that the brakes on our Toyota Tundra start to warp because they take the full brake force. Any ideas on what could be going on here? Regards, Silke & Felix

OK, it sounds like you have a hydraulic problem. If you have brake fluid in the master cylinder, you have either a non-working master cylinder, non-working calipers or air in the brake lines. I suggest the first step is to try bleeding the calipers. That will tell you if you have air in the lines and if the master cylinder is functioning properly. If you crack the bleeder valve and you get nothing, you may have to rebuild the master cylinder. if you get fluid, but the brakes still don't work, the calipers are no good and they will have to be replaced. it's not uncommon for the calipers to corrode and lock the internal pistons. If you are to that point, I'd just rebuild the entire brake system. As you have found out, you need good brakes.

Good luck,
Pat

[Québec 1]

I brought my trailer to the garage today for a pre trip check up. I found out that my trailer brakes did not work anymore. My mechanic checked the brake fluid and found it was empty. He took the tire off and showed me how to bleed the brakes. I bled the brakes for 1hr. The bakes work now. Seems the brake oil evaporated from being outside all summer.
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[dca81]

Also ensure that your trailer hitch is sliding freely to activate the surge brake. It can get dirt, rusted or bent and will not slide. I have an 04 trailer and a repair shop did not have the reverse light set up to lock out the surge brake when you back up. So they put a large c-clamp over the hitch where the grooves are on the side. Now the surge does not work because they bent the hitch housing and it does not slide freely. I'll work on it and get it working ...but hate to say how much I paid for this example of great American craftsmanship.

[silkefelix]

Thanks for your good tips everyone! With the help of someone else my husband worked on the trailer and now everything is fine. Regards, Silke (& Felix)

[Kelly Hanson East]

Seems the brake oil evaporated from being outside all summer.

Not very likely imho. Its Poly-glycoxyethers which is chemical jargon for big organic molecules that dont evaporate very fast. My guess is you have leak.

Another point - it isnt necessary to change master cylinders when you from drums to discs.

[Just Nuisance]

Hi
I found my master cylinder empty when I bought my boat as well. I had to dismantle, clean and rebuild it. I didn't find any leaks anywhere, but I don't think the PO monitered the level( 8 years). Just so you know, If you are going to change from drums to discs and don't want to replace the master cylinder you will have to remove the residual valve. Here is a link.

http://www.championtrailers.com/remove_ ... _valve.htm

Regards

Mike
Just Nuisance

[Paul S]

Just about all m trailers will run into this problem.

The brake line comes out of the tounge and along the frame. THe line rubs against the steel tounge..and rubs..and causes a leak or loss of pressure.

The fix is to 1) get a new line (SS preferably - not expensive and available pre-made) and put some chafe guard on the hole!!

I had this problem with the original trailer. I bought a used M trailer (thanks Dan) and it had the same problem.

If you have an M trailer, at least the steel trailer, you will have this problem..if not now, you will at some point.

All the vibration and bouncing..causes the line to chafe..

How are these trailers even legal??

Disconnect the trailer plug..back up. The M trailer, with properly working brakes, WILL NOT allow you to back up at all. Period. If it does, there is a problem. Look at it or have someone look at it .

[trip01]

Rather than starting another thread, I placed my mod here....
I was concerned about the flexible brake lines chafing on the trailer frame at the wheel, axel & 'A' frame area. As per photos....







My remedy was to install 10mm split wiring loom over the lines to protect them.

I notice another area of concern at the 'A' frame where the aluminium connects to the black steel section at the jockey wheel area of the trailer. Rust

Any one else...

To dismantle for rust treatment and recoat, I would have to disconnect the brake lines.

Kind Rgds
Dave
2008 26M Alloy Trailer

PS notice the recarpeted bunks

[Québec 1]

Seems the brake oil evaporated from being outside all summer.

Not very likely imho. Its Poly-glycoxyethers which is chemical jargon for big organic molecules that dont evaporate very fast. My guess is you have leak.

Another point - it isnt necessary to change master cylinders when you from drums to discs.

Your right.....I found the leak and repaired it this summer.
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