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DOCTOR-MX · 01-07-2008, 09:07 PM

I have a TT with a tandem 2 axles, only one with electric brakes but I feel is not enough to stop it safely, it weigths about 7k. Im going to add breaks to the other axle, Im going to order the parts, but my question is: the new backing plates has the oval magnet and the old ones in the other axle has a round magnet, can I upgrade the old ones whit a new oval magnet or buy a new round magnet?
thanks in advance.

markdoane · 01-07-2008, 09:14 PM

The round and oval magnets are not interchangeable. You may want to upgrade the original brakes with new loaded backing plates also; they're not very expensive and then everything will be the same.

Be sure the brake wiring is at least 12 ga.

Zeppelinium · 01-08-2008, 03:21 AM

Get two new backing plates. They are only about $50, which isn't that much more expensive than a new magnet and you get all new mechanism. I've had the swing arms or their posts fail on old electric brakes and lock up the whole wheel.

Zep

DOCTOR-MX · 01-08-2008, 11:43 AM

Ok, thank all of you, and you are right, I think is better to change the old braking plates, to match them up with the new ones in the other axle. Do you think I can use the drums? or I should buy a new ones?

Thanks a lot.

Zeppelinium · 01-08-2008, 06:36 PM

The old drums will work, as long as they haven't been reamed out more than once--same specs as if you didn't change out the plates. I think I'd get four plates.

Pounding the press fit bolts out of the old plates is a real exercise. You might also want to buy a set of bolts for each plate.

Zep

DOCTOR-MX · 01-09-2008, 04:46 PM

Thanks a lot sir. Ill follow your recomendations.

DOCTOR-MX · 01-28-2008, 08:02 PM

OK, Im in the middle of the work and I have a couple of questions:

1.- How is the way to give the "torque" for the spindle nuts?. Some said: put the nut with pressure finger and then torque it a 1/4 clock wise with a tool. others said: torque it with the tool strong and then return 1/4 counter clock wise.

any ideas.

2.- The bolts from the backing plate are to short for the plate in the axle and I cant get here a longer ones, with the striate, can I put a longer regular bolts (grade) instead of the OEM?

thecatsandi · 01-28-2008, 09:46 PM

Quote:

Originally Posted by DOCTOR-MX

OK, Im in the middle of the work and I have a couple of questions:

1.- How is the way to give the "torque" for the spindle nuts?. Some said: put the nut with pressure finger and then torque it a 1/4 clock wise with a tool. others said: torque it with the tool strong and then return 1/4 counter clock wise.

any ideas.

The torque spec should come with axles. You will need to torque them to say 15 ft-lbs rotate clockwise and then back the nut off loose. Turn the nut hand tight then until it drags slightly. Check for play by grabbing the tire on the front and back pull on one side then the other. Grab it on the top and bottom and do the same. rotate the tire and see if there is slight drag again. It should be good.
The ultimate authority is the manual.

DOCTOR-MX · 01-29-2008, 09:37 AM

thecatsandi thank you for your comments.

DOCTOR-MX · 01-29-2008, 09:50 AM

BTW what about this question:
The bolts (studs?) from the backing plate are to short for the plate in the axle and I cant get here a longer ones, with the striate, can I put a longer regular bolts (grade) instead of the OEM?

Greg@AirLA · 01-29-2008, 10:23 AM

The splined bolts are easily relaced with a Grade 8 bolt, nut and lock washer, that's generally what comes with new backing plates. One word of caution, the older drums had a re-enforcing lip cast on the edge, this may interfer with the rolled edge on the newer style backing plates. You can have this lip relieved slightly at the same time you have the drums and armature plate trued.
Greg

DOCTOR-MX · 01-29-2008, 10:34 AM

Ok, thanks GREG@INLAND, thats what I thougth; and about the drums Im changing all, four new backing plates and four new drums. but that was a good point.

Thanks again, best regards.

DOCTOR-MX · 02-06-2008, 08:56 PM

Well I changed backing plates and drums, and all the wires, hot and ground with a 10 gauge wire, direct from the magnets to the connector, should I connect the ground wire also to the frame of the trailer?.

Thanks in advance.

Zeppelinium · 02-07-2008, 07:17 AM

Quote:

Originally Posted by DOCTOR-MX

Well I changed backing plates and drums, and all the wires, hot and ground with a 10 gauge wire, direct from the magnets to the connector, should I connect the ground wire also to the frame of the trailer?.

Thanks in advance.

You've got a separate ground wire from inside the trailer, like coming from a wire bundle? Both sets of brakes I've worked on only have a hot wire--the ground in both cases is connected to the frame close to the axle. It seems to me that making a ground connection to the frame would help in two ways--lower the overall impedence and provide a redundant ground path (increasing reliability).

Zep

DOCTOR-MX · 02-08-2008, 10:33 AM

Zep, thanks, I didnt understand very well your question: You've got a separate ground wire from inside the trailer, like coming from a wire bundle? but I think I dont have a separate ground from inside the trailer.

I put two new wires (#10 gauge) from the connector in the umbilical cord, one for the trailer brakes (power) to a junction box then to the one of the wires of the magnets like in the trailer 2 (I only change that using the SAME length of wire for each brake from the j. box, like a spider), and the other for the ground in the same way (of course in a separated j. box) to the other wire of the magnets (they are not connected to the frame close to the axle), and my question was if I should connect the ground wire also to the frame of the trailer? But according what you wrote, I should, to lower the overall impedence and provide a redundant ground path (increasing reliability), right?

Zeppelinium · 02-08-2008, 11:42 AM

you misunderstood me. I was asking if you had a separate ground wire from the umbilical. I don't. I just have a ground connection to the frame close to the axle. As long as you have a good ground, it really doesn't matter where or how you get it as long as it's reliable. Two grounds would be just a little bit better.

You don't have to worry about making the wires the same length. That's only for high frequency radio stuff.

Zep

DOCTOR-MX · 02-08-2008, 01:53 PM

ohhhh I see. In other forums they claim that the same length is very good and thats the reason for a "star" wiring. I really doesnt know, any way in my logic it seem to be right, but electronics are othere thing.

BTW, I have a DrawTite 2-4 Brake Electronic Brake Controller - Time Delayed, should I change it for a Tekonsha P-3 Trailer Brake Controller – Proportional for even better braking?

Zeppelinium · 02-08-2008, 03:16 PM

Quote:

Originally Posted by DOCTOR-MX

...BTW, I have a DrawTite 2-4 Brake Electronic Brake Controller - Time Delayed, should I change it for a Tekonsha P-3 Trailer Brake Controller – Proportional for even better braking?

I'm not a controller expert. Proportional braking systems are better, but at the cost of added complexity in getting them installed and calibrated. I don't know if the calibration is a one-time issue or crops up now and then. Calibration is the process of getting the controller "level" so that it senses your braking effort and not the uphill or downhill tilt of the box.

Zep

AirstreamGypsy · 02-09-2008, 08:11 AM

I have the Tekonsha P-3 Trailer Brake Controller. Used to have the Draw-Tite. I like the Tekonsha waaaaayyy better. No more difficult to install. Although you can probably leave it alone after you calibrate, I am a fiddler and you can easily tweak the settings for unusual situations.

DOCTOR-MX · 02-11-2008, 10:24 AM

Thanks for your comments, I am planning to buy the Tekonsha P-3, but now somebody recomend me the BRAKESMART, and now I dont know, the brakesmart is more expensive but tu be seem that is the bullet ??. does it worth ?