New to the forum. I just bought a 2003 Merhow 3 horse slant with 10 foot LQ. Its been sitting for a year or so. Not used much before that. Tires look new but aren't. Hooked up. Manually applied brake controller. Can hear the brakes hum sitting still. Pulled off and no brakes. Drove a ways,checking them manually with the controller. They started working and had to back off controller somewhat to keep tires from skidding. Got new tires. Drove off. No brakes. Same deal. started working. Stopped for dinner. Same thing. Once they start working they work fine. Any thoughts? Thanks.
Posted 2011-06-15 11:09 PM (#134888 - in reply to #134884) Subject: RE: Trailer brakes
Expert
Posts: 5870 Location: western PA
Two things: When a trailer sits for a while, the drum accumulates a light coating of rust. Your first brake application will not be as effective as the magnet cleans things up a bit. The second is the brakes should be adjusted for optium performance. When they wear, they become more spaced from the drum and have to move further for an application. It may take multiple applications to apply worn, unadjusted brakes.
Posted 2011-06-16 7:04 AM (#134893 - in reply to #134884) Subject: RE: Trailer brakes
Member
Posts: 9
Gounds where? Last time I pulled another trailer last month there were no issues. I will be pulling the other trailer this Saturday and I will check the brake opration on it then. The contoller is a low end older Reese.New in 2003. Was thinking about a up grade. Prodigy2? More advise please.
Posted 2011-06-16 7:31 AM (#134897 - in reply to #134884) Subject: RE: Trailer brakes
Extreme Veteran
Posts: 342 Location: Ohio
I would check the controller first.
Normally trailer brakes ground right above the axle on the frame. I would check all wire connections all the way back to the brakes, including the plug end after ruling the controller out.
I've heard of good reviews about the Tekonsha P3 brake controller.
Posted 2011-06-16 10:12 AM (#134899 - in reply to #134897) Subject: RE: Trailer brakes
Location: Kentucky
Sounds like the trailer needs a brake inspection and adjustment from an experienced technician. Also wheel bearings should be inspected and repacked. If grease from the wheel bearings has, over time, melted and gotten onto your brakes it can cause problems with braking as well. I would not suspect electrical issues until mechanical ones have been ruled out. An 8 year old trailer that has been sitting for the past year needs to have these inspections done anyway. Good luck and hope it's an easy fix!
Posted 2011-06-16 11:01 AM (#134900 - in reply to #134884) Subject: RE: Trailer brakes
Member
Posts: 9
Problem is finding a shop/tech. Just about have gone out of business. I kinda figured on a brake check/wheel bearing thing. Trailer has very few miles on cinsidering the condition of the tires that came off it yesterday. Hardly any wear at all. Its been sitting longer then a year since 2003. Gonna call a few places and see if I can find someone to work on it. Thanks for the help.
Posted 2011-06-16 11:32 AM (#134901 - in reply to #134884) Subject: RE: Trailer brakes
Extreme Veteran
Posts: 342 Location: Ohio
I agree with Kentuckyrain about the general maintenance. A good greasing and coat of silicone grease or wd40 would be good. It would be good to make sure nothing is froze up in there. To be honest, theres very little that can go wrong mechanically in electric brakes, but its good to rule it all out before tackling wiring. It's a bear.
Depending on how the brakes are wired, individually or in series, there could be a magnet bad (or going bad) causing the intermittent braking.
The intermittent braking is why I'm leaning toward an electrical issue.
I just dealt with this on one of my trailers. The last we used it was mid-October last year and the brakes worked fine. We got it out to use it a few weeks ago and the brakes were intermittent similar to yours. All grounds were corroded as well as where the lead wires off the brake assemblies attached to the wires that ran to the truck plug. I ended up completely rewiring the brakes and instead of attaching the grounds to the frame, ran a ground wire all the way up to the truck. Had no issues and the brakes feel strong.
Posted 2011-06-16 2:52 PM (#134903 - in reply to #134884) Subject: RE: Trailer brakes
Expert
Posts: 5870 Location: western PA
With a modicum of mechanical ability, many people are capable of jacking a wheel, spinning it and manipulating the star adjuster whilst adjusting the brakes. It takes less than five minutes a wheel, and the only tool needed is a common screw driver. This is a maintenance item often neglected by trailer owners, one that is necessary as the trailer is used.
The brakes will need to be adjusted, regardless if the propblem then is discovered to be electrical. This is because " the brakes should be adjusted for optium performance. When they wear, they become more spaced from the drum and have to move further for an application. It may take multiple applications to apply worn, unadjusted brakes."
It is unlikely that bad ground wires from the brake assys to the frame are the cause of your problem. More than one wire loosing contact at the same time is improbable. Having good brakes, not intermittent once they do apply, may also rule out the feed wire to the brakes.
The only other common item is the controller, and the brake adjustments. The brakes cost only a little time to trouble shoot; the controller can be expensive to change if it is not the problem.
Posted 2011-06-16 11:20 PM (#134913 - in reply to #134899) Subject: RE: Trailer brakes
Veteran
Posts: 201 Location: Lincoln, NE
My local mechanic is able to repack trailer wheel bearing and adjust brakes. If you can't find someone with the skill, training to do so locally you may have to haul to a larger city (there are some in KY). But any truck/trailer place could do it. I've also had that work done at my local RV service department.
Posted 2011-06-17 2:04 AM (#134915 - in reply to #134884) Subject: RE: Trailer brakes
Expert
Posts: 3853 Location: Vermont
Originally written by ticklebritches on 2011-06-15 8:44 PM
New to the forum. I just bought a 2003 Merhow 3 horse slant with 10 foot LQ. Its been sitting for a year or so. Not used much before that. Tires look new but aren't. Hooked up. Manually applied brake controller. Can hear the brakes hum sitting still. Pulled off and no brakes. Drove a ways,checking them manually with the controller. They started working and had to back off controller somewhat to keep tires from skidding. Got new tires. Drove off. No brakes. Same deal. started working. Stopped for dinner. Same thing. Once they start working they work fine. Any thoughts? Thanks.
Here are some possible issues...· Open on electric brake circuit· Power backfeed on brake circuit output wire.· Open on ground circuit of trailer or truck.· Faulty control
Posted 2011-06-17 5:33 PM (#134928 - in reply to #134925) Subject: RE: Trailer brakes
Expert
Posts: 3853 Location: Vermont
Originally written by ticklebritches on 2011-06-17 12:52 PM
Yes. Works correctly.
Then your problem is in the trailer...Check these possible situations...· Open on electric brake circuit on the trailer.· Power backfeed on brake circuit output wire from the trailer.· Open on ground circuit of the trailer.
Posted 2011-06-18 6:41 AM (#134930 - in reply to #134890) Subject: RE: Trailer brakes
Expert
Posts: 2689
Originally written by ticklebritches on 2011-06-16 4:36 AM
How does the out of adjustment explain no braking at all then they start working after a few miles and reappling several times?
It doesn't (-:
There are any number of possibilities here, i.e. there may be more than one problem causing what appear to be conflicting symptoms.
Brakes that "go away and then come back" can often be traced to wiring issues, sometimes the tow vehicle, sometimes the trailer, sometimes the connections between them.
Motion can cause poor connections to make, then break, then make in very unpredictable ways.
I would first check that your rig has a good ground between the tow vehicle and trailer, do NOT depend on the ball and coupler for this.
It is typically a white wire, but that is just a convention.
Electrons don't care what color the wire covering is.
This may seem counter to what I just wrote, but frame ground IS typically used for brakes and lights, so although ball and coupler aren't good enough the rest of the frame is.
OK, assuming that can get all wrung out and the problem(s) remain I would start in on a brakes and bearing job.
Unplug it from the tow vehicle, but keep it attached and jack up one side to remove both wheels.
Then run long wires to each side of the breakaway switch so that I could activate the brakes from where I work at the side of the trailer.
CAUTION: By jumpering out the breakaway switch you will be applying FULL 12 volts (probably 10 or 11 since it isn't on charge) to the brakes, i.e. it will not be attenuated by the brake controller. There is little/no chance of burning anything out, but you will be drawing a full 12 amps from that little emergency brake battery.
For most of what follows you should only have to apply the brakes this way for a second or two for testing.
With both wheels removed, but the drums still on, spin each drum forwards.
Apply the brakes with the jumper wires and try to get some sense of one being stronger or coming on faster than the other.
You MIGHT be able to turn a wheel by hand with the brake fully on, if so you are BADLY in need of a brake job. I would get parts on hand before going any farther.
You might have what Dexter call "Forward Self Adjusting" brakes.
If these are working correctly they should be properly adjusted.
You could have reverse adjusting brakes, which only adjust when you apply them while backing up.
If the previous owner had a habit of just shifting between reverse and forward it is POSSIBLE that the brakes were never automatically adjusted.
You can "feel" for wheel bearing looseness while doing this too.
From here on... If you have "never done a drum brake job" before you may want to get some help from someone who has...
It is time to pull the drums, you MIGHT find almost anything once they're off; worn magnets, failed oil/grease seals, grease on linings, worn linings, etc.
Much will depend on any competence you have for general mechanical things, I can't advise you to proceed with this or not to.
Probably the greatest risk for a neophyte (not suggesting that you are) is over tightening of the big spindle nut when you put it all back together.
My guideline for that is "Hand tight and you should barely feel 'play', then back it off until the cotter pin fits, e.g. 1/12 of a turn or so".
Posted 2011-06-18 7:08 AM (#134933 - in reply to #134884) Subject: RE: Trailer brakes
Expert
Posts: 2689
PS to last message;
It is GENERALLY worth replacing manually or reverse adjusted brakes with forward self adjusting brakes if you are doing a replacement job anyway.
It is also generally easier and simpler to replace the whole assembly than to mess with separate shoe, springs, magnet replacement. I think the cost difference is less than $5 per wheel for the typical (relatively) light horse trailer with under 12 inch drums.
BTW, if you don't want to get into all this and have no "horse trailer" shops nearby you can seek out shops that service other trailers, e.g. construction equipment trailers.
BobCat and back hoe trailers are in about the same weight capacity class as your trailer, so have similar brake systems of same size, anyone who services those would have the skills and tools to do yours.
Posted 2011-06-18 7:49 AM (#134934 - in reply to #134884) Subject: RE: Trailer brakes
Member
Posts: 9
I have no desire to pull drums here at the house. Years ago maybe. Not now. Previous owner says his son owns a auto repair facility and last year pulled drums,inspected,packed bearings etc. Then it didn't get used but once or twice since then. I kinda hinted for him or me to take it there. He said his son is trying to close the doors on his business this very week.. RV shop about 30 miles away has one tech. Tech has a rep for being really good in all aspects of rv repair. He's booked forever. RV store owner says he hasn't sold but two travel trailers in about 2 years. But the service end of it has filled his 5 acres to the brim with work. Got the name and number to another shop about 30 miles away from my vet. That guy when I called started off with how sorry electromagnetic brakes were and went on and on about converting to electric/hydraulic and such. I told him half a dozen times that I wasn't interested in converting anything. Just wanted what it had to work from the get go. Not miles down the road. Bout couldn't get him off that subject. Vet swears he does excellant work and knows what he's doing. I might drive to him for a 'discussion' and so I can see his shop. Says he's got a secure holding area and a shop big enough to pull road tractors/trailers into. To feel hiim out a bit more I mentioned to him that I had ordered a electric lift conversion for the landing gear that I would need installed. He said he installed such with no issues etc. Just guessing I think its got a corroded ground( I might look into that today) or magnet/shoes sticking.
Posted 2011-06-18 8:15 AM (#134935 - in reply to #134884) Subject: RE: Trailer brakes
Expert
Posts: 2689
A corroded ground is a distinct possibility.
If you can trace a (usually white) wire from the trailer plug to a frame connection you may be able to verify it as a suspect by putting the lights on and watching them while someone tries wiggling the ground wire.
This is usually a fairly short wire and connects somewhere on the trailer tongue.
If the lights flicker - Ta Dahh... gottit.
If you can't get a helper just finding any looseness at the ground wire to frame connection would be something worth fixing.
Take it OFF, wire brush to clean metal, reassemble, paint over after assembly, etc.
BTW, WD-40 is NOT a good cleaner for electrical contacts, it is an OIL and will gum up eventually.
A can of contact cleaner is well worth the money, probably $7.99 or so at Radio Shack, if you still have one near you (-:
Trailer brakes
