Maintenance & Restoration

wklose99 · 08-05-2012, 06:16 PM

I just had brand new e brakes installed on my '81 burro wheels because the trailer shop told me the original brake magnets had melted. I have a p2 prodigy brake controller, which seems to be properly installed. I am towing with a ~4500 ford escape, and the trailer weighs 1250 with 14" wheels and 7" drum brakes.

When i picked the trailer up yesterday, i plugged everything in and then followed the instructions for calibrating the p2 controller. I drove at 25, and then put max power to the brake controller. I could hear them click through my window, but the wheels did not lock up like the manual said they should. I also did not feel the trailer tug on my car. I also could not feel a decisively noticeable difference between braking with and without the controller on or off.

I went back to the trailer store, and he said he could hear them activate, and that they need to be broken in and then they should lock up the wheels (when full power is applied to brake controller).

My question is, should i feel a noticeable difference on my 4500 lb car when braking with the 7" drum brakes? Even if i shouldnt be able to feel it, should i be able to see or feel the brakes lock up when i apply full power to the rale controller? And lastly, is this a 'break in' issue or is there something wrong?

Thanks for any help!
-will

Roy in TO · 08-05-2012, 07:40 PM

Assuming you have Dexter Brakes, this may help:
Dexter Axle - Trailer Axles and Running Gear Components - FAQ'S

Specifically this quote:
"BRAKES - Why can't I lock and slide my electric brakes?
On an unloaded trailer, you may be able to lock up your brakes if your electric brake controller is supplying full amperage to the brakes. When loaded to capacity, you may not be able to lock your brakes as electric brakes are designed to slow the trailer at a controlled rate, and not designed to lock up the wheels on a fully loaded trailer. Our brakes are designed to meet all applicable safety standards. All of our brakes will perform better after numerous burnish stops to seat the brake linings to the drums."

You should consider your trailer essentially loaded, since it is heavier than an empty boat or utility trailer. It is not fully loaded, but loaded.

Daniel A. · 08-05-2012, 08:05 PM

If the P2 is basically the same as the P3 just not as advanced much would depend on what you have the power button set to, if the wheels lock to much power, if braking is not sufficient more power to the controller.

The trailer brakes need to be warm for better response.
You may not feel it given the light weight but you should hear it if they lock.
The fact you can hear the hum from the magnets says yes they are working and may need some miles to break in.

To satisfy yourself you could lift one side and have someone tap the brake while turning the wheel and know if they need more adjusting.

Bottom line is the trailer shop should know if the adjustment is correct.

Perry J · 08-05-2012, 10:04 PM

I have replaced brakes on at least 5 or 6 Eggs in the past 7 years.
I was able to lock all of them up on the first test drive.
The heaviest trailer I've owned is a 16'SD Scamp with a bath.
Fully loaded I could lock the brakes.
IF your controller is functioning properly and the brakes are working properly you should be able to lock the trailer brakes.
I think you need to speak to your installer and tell him you want the brakes to work and it's his responsibility to make them work.
They may not be adjusted properly.
Magnets wear out from rubbing on the face of the drum. I've never heard of them melting.
You will feel a tug on the back of your vehicle with properly working brakes.
No tug, no trailer brakes.

John

floyd · 08-05-2012, 10:49 PM

I have yet to see 7" brakes lock up (at least not above 10MPH)
They should do their share of braking though and should pull down pretty hard.
An Escape's curb weight is more like 3200 pounds...4500 pounds would be GVW.
As for break-in on the brakes,they should work when new, but may show improvement when adjusted after a few hundred miles.

Ron in BC · 08-05-2012, 10:50 PM

Gotta say, everything John said matches my experience. When I did my first test drive there was absolutely no doubt in my mind whether the brakes were working or not. They locked up, which in itself make a fair amount of noise and I could feel the pull on my truck. Had to dial my Hopkins controller down twice to get to a non lockup setting. Been on 4 trips with them and they havn't required any change in the setting.

Ron

Byron Kinnaman · 08-05-2012, 11:44 PM

Quote:

Originally Posted by floyd

I have yet to see 7" brakes lock up (at least not above 10MPH)
They should do their share of braking though and should pull down pretty hard.
An Escape's curb weight is more like 3200 pounds...4500 pounds would be GVW.
As for break-in on the brakes,they should work when new, but may show improvement when adjusted after a few hundred miles.

Yup, Yup, Yup

ruscal · 08-06-2012, 01:15 AM

Now days brake shoes have high spots that need to wear down to increase the contact area. In the old days before we knew asbestos was bad for us it was common practice to arc the linings to fit the drums by grinding. That made for a short break in process since the whole lining was in contact with the drum. I would bet some linings fit better than others right out of the box. Some mechanics will bend the shoe to make it fit closer. The closer the fit the shorter the break in period will be. It is not good practice to hurry the break in by dragging the brakes or doing multiple panic stops, as the small contact area of the shoe will get blazing hot, and may be harmed. Too light a pedal pressure is not desirable either, just drive normally. In your case, if all the electrics are properly applying current to the magnets it may be that poor fit on the shoes is causing the lack of braking friction. It will improve with use. You should feel the trailer slow the TV when using the controller lever.
Russ