Will a dirty magnet cause intermittent brakes?

[krazymatt]

So as I continue on my quest to solve my intermittent brakes issue I took off one drum and there is a film of grease on the drum and magnet probably from those useless easy lube fittings. There was a surplus of grease even in the dust cap. Would that cause intermittent brakes that work one minute and not the next?

[krazymatt]

I wanted to Update you all on my brake issue. I replaced all four magnets since I was going to repack my bearings anyway, adjusted the brakes and replaced the wires from one axle side to the other and my problems seemed to go away. Thanks for all the input!

[Bamaman11]

You can replace the grease seal, clean up the brakes and even sand the brake pad somewhat. It may get you back on the road.

[krazymatt]

I found a place online (Libra trailer parts) that sells kits or pairs for 29 bucks shipped. Hard to beat. New backing plate setups would run in excess of $200. We don't plan on keeping this 5er too long as it is a 2002. I just want working brakes.

[minnow]

DmaxWW wrote:
You may find that it's cheaper (and easier) to just replace the assembly instead of buying piece parts.

Agree. If you have had grease on the brake pads, they will never be 100% no matter how much you clean them. Four bolts and connect the wires and you have new brakes, springs and magnets.

[Timay]

Will a dirty magnet cause intermittent brakes?

The answer is no...keep looking...

Tim

[Vette_Racer]

You may find that it's cheaper (and easier) to just replace the assembly instead of buying piece parts.

[krazymatt]

Well I did the below test i found on etrailer on one of the magnets and it failed. It read 5 amps so I guess for starters I need to order new magnets.

Testing Individual Brake Magnet for a Short

To determine if a brake magnet has an internal short, touch the base of the brake magnet to the negative post of a 12-volt battery. Then, connect one of the brake magnet wires to the negative lead of a multimeter and the positive lead of the multimeter to the positive post of the battery. If any amperage is detected, the magnet is shorted and will need to be replaced.

[Denny___Jami]

If you have grease on your shoes and magnets you will have to clean that up before you can diagnose any other problem.

Denny

[Likes_to_tow]

Intermittent loss of brakes can be caused by the wiring on your axle!! Most common routing of the wires going from one side to the other is through the axle. Check and see if they drilled a small diameter hole in the axle to run the wires to the other side. After continuous bouncing, the insulation on the wiring will wear off even inside the axle tube where you can't see it. Eventually a bare wire will allow the brake voltage to "ground out" and no current is applied to the brakes!! When I heard of this common problem a few years ago I removed the wire inside the axle tube and tie wrapped it to the back side of the tube then reconnected the wires with solder.

Agree with grease being on the brake shoes but in my experience this just causes a constant poor brake actuation. Sudden or intermittent loss of brakes is a poor connection or a chafed wire somewhere!!

[Golden_HVAC]

I am taking a guess. Grease under the magnet will allow a lot of slippage, but once it warms up, it will burn away any grease, so you will not see it later.

So yes it will apply once the grease is gone because it got hot enough due to applying.

How do the shoes look? If they have grease on them, then you might need to replace the shoes.

Most of the time intermittent brakes would be caused by a loose connection. Check all your wiring. If one brake shoe looks 'great' while the other suggest being worn a bit, then you might have one bad magnet. A compus will read 'north' while the brakes are energized if it is working. You can pull the emergency pin, and it will energize the brakes with a full 12 volts to test it, but do not leave them on to long (1-2 minutes) as you can overheat the magnets.

You can also price out disk brake conversions here. ETrailer.com

Fred.

[Old-Biscuit]

Magnet needs a grease free surface to 'grab' in order to rotate and cause brake shoe lever to engage.
Magnet will naturally 'slip' as it reaches full travel and drum continues to rotate but grease film will not allow it to remain at full extension holding brake shoes out against drum....magnet will 'skip' making shoes grab/not grab

[azrving]

Grease on the shoes is going to give you poor braking all the time it would seem. A bad connection could give you and intermittent problem. The brake connections under my rig used wire nuts. It's quick and easy for the people who assemble it but it wont hold up to the elements. I soldered and used electrical grease in heat shrink tubing on mine. Check the grounds also. You need to inspect the whole system.