Electric Trailer Brakes performance
Submitted: Sunday, Aug 03, 2008 at 12:46
ThreadID:
60437
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Replies:
8
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Member - Kevin D (VIC)
Got a reasonable new camper trailer and the electric brakes don't quite work to the level I thought they would. Either I'm expecting too much or they're not working properly. Given I have never used trailer brakes before (read clueless), I thought I'd ask and get a few opinions.
OK, Trailer is empty apart from the
water tank which is about half full and a battery. Should weigh around 600Kgs (Guess). It supposed to take about 1200Kgs fully loaded.
I've tried the trailer on 2 vehicles (Patrol and Magna) and got similar result. (To try and eliminite the vehicle/wiring/controller)
Using the manual override, travelling at 60Km on the black stuff, I can "feel" the trailer braking, but the
wheels are nowhere near locking.
On dirt (not bone dry, rained on recently) I can't get them to lock (although they would lock occasionally if I used the vechile brakes as
well)
On wet dirt the
wheels lock.
On wet bitumen the
wheels lock.
So, given the trailer isn't loaded up, am I expecting to much? I would have thought the
wheels should at least lock up on bitumen when the trailler is bascially unloaded applying full brakes/voltage.
The trailer has the magnetic type brakes.
Reply By: Member - Roachie (SA) - Sunday, Aug 03, 2008 at 13:32
Sunday, Aug 03, 2008 at 13:32
Ahhh, electric trailer brakes....ya gotta love 'em, don't ya!!!!????
They are one of the most unreliable things in our rig set-ups I reckon.
The fact that you CAN actually get them to lock up under certain circumstances, would tend to indicate that the brakes themselves are set-up correctly.....however, you may need to make some adjustments to the in-car brake controller. Best way is to find a quiet road and just play with the adjustments as you drive along at a sedate speed (say 40k/h) until you feel them wanting to lock up.
If they are very new, you will have to give them time to bed-in as
well....
Cheers
Roachie
AnswerID:
318768
Reply By: Shaker - Sunday, Aug 03, 2008 at 13:47
Sunday, Aug 03, 2008 at 13:47
Have you adjusted the brake shoes?
AnswerID:
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Follow Up By: Ken65 - Sunday, Aug 03, 2008 at 21:08
Sunday, Aug 03, 2008 at 21:08
Check you are getting the correct voltage to the brake magnets. First thing I would personally check though, adjustment of trailer brakes. When I checked
mine for poor performance I found the adjustment was made on the handbrake rather than the adjuster on the shoes.
FollowupID:
585366
Reply By: Member - Olcoolone (S.A) - Sunday, Aug 03, 2008 at 13:53
Sunday, Aug 03, 2008 at 13:53
What controller?
AnswerID:
318771
Reply By: Member - Kevin D (VIC) - Sunday, Aug 03, 2008 at 13:57
Sunday, Aug 03, 2008 at 13:57
Shoes have been adjusted. (I took it back to the manufacturer since they did almost nothing to begn with. They are better, but...)
The trailer has been on 3 trips (approx total distance 2000kms).
The in car brake unit is set to max. (It's a tekonsha prodigy). Applying 12+volts to the brake when I use the manual override fully.
All the testing as stated above is using the manual override (fully) only. (not using the car brake pedal).
I know they work, but I concern once the trailer is fully loaded they won't work
well enough.
Let me put it down to a simply question, should I be able to lock or almost lock the trailer
wheels dong around 60kms on dry bitumen by applying the manual override fully (Ie, full braking)?
AnswerID:
318772
Follow Up By: Shaker - Sunday, Aug 03, 2008 at 13:59
Sunday, Aug 03, 2008 at 13:59
The instructions for the controller tell you at what speed to test for 'lock up' on bitumen.
FollowupID:
585278
Follow Up By: Member - Kevin D (VIC) - Sunday, Aug 03, 2008 at 14:09
Sunday, Aug 03, 2008 at 14:09
From the horse's mouth
"2.With engine running hold manual full left and
set power knob to indicate 6.0.
3. Drive tow vehicle and trailer on a dry level
paved surface at 25 mph and fully apply
manual knob
4. If the trailer
wheels lock up, slightly reduce
power by adjusting the power knob. If the
wheels turn freely, increase power to a point
just before wheel lock up."
FollowupID:
585279
Follow Up By: Member - Olcoolone (S.A) - Sunday, Aug 03, 2008 at 14:29
Sunday, Aug 03, 2008 at 14:29
Have you tried the boost function?
FollowupID:
585282
Follow Up By: Member - Kevin D (VIC) - Sunday, Aug 03, 2008 at 14:34
Sunday, Aug 03, 2008 at 14:34
When I originally put the prodigy in I did. (I pulled out the original unit when I got the trailer as I thought it was probably knackered.)
Haven't tried it recently, but I give it a go a little later today.
FollowupID:
585283
Reply By: Member - Glenn H (NSW) - Sunday, Aug 03, 2008 at 14:09
Sunday, Aug 03, 2008 at 14:09
Gidday Kev, lecky brakes are finicky beasts to say the least!!
Mine are on a 1000kg laden van but will lock one wheel on the tar if full voltage applied. One brake drum is probably a bit out of round so the shoes grab.But this is a little dangerous. I have a bit of a play with the settings so I can feel the van pull up the car using the thumb control.
In traffic they are a pain as they grab too easily at low speeds, so I have to compensate for that.
Creek crossings and dust mess them up too. Actually I just took the drums off last week to check the bearings and noticed that the magnets were very wobbly on the lever they sit on so I put in some shims. Might be worth checking yours.
Mine have done 30,000km in 3 years including the GRR and
Cape york and have had a hiding. You just have to get familiar with their cantankerousness. Cheers, Warrie
AnswerID:
318775
Reply By: kiwicol - Sunday, Aug 03, 2008 at 15:18
Sunday, Aug 03, 2008 at 15:18
Another problem that has a big affect is the cross in the magnet where the holding bracket fits flogs out, and can be different on both sides, this can cause one wheel to lock up or not work efficiently. I had the same problems and ended up throwing the electrics and using the overide. I fitted an adjustment on the cable near the hitch so i didnt have to keep getting underneath to adjust. When loaded the trailer is about 1.2 Tonnes. Col
AnswerID:
318787
Reply By: Member - William B (The Shire) - Sunday, Aug 03, 2008 at 15:55
Sunday, Aug 03, 2008 at 15:55
Hi Kevin,
I have not had a lot to do with electric brakes, but I remember my Uncle having a similar problem.
Brakes worked slightly, 12volts at magnets.
The problem was there was 12volts but because of a cut in the wire the brakes were not recieving full power. (amps?)
So every thing appeared to be working but no real "grab".
Hope that makes sense,
William
AnswerID:
318797
Follow Up By: Member - Roachie (SA) - Sunday, Aug 03, 2008 at 16:17
Sunday, Aug 03, 2008 at 16:17
Yes, this is another important point......amps!!! It is crucial that ALL the wiring for the brakes is of a decent size. The cabling from the controller to the trailer plug, the input power supply to the controller and of course the wiring on the trailer itself; all needs to be 6mm sq to be effective.
FollowupID:
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Follow Up By: Holden4th - Sunday, Aug 03, 2008 at 17:37
Sunday, Aug 03, 2008 at 17:37
Which is why I fitted a large/round/ 7 pin connector to my tow bar.
FollowupID:
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Follow Up By: Gronk - Sunday, Aug 03, 2008 at 18:25
Sunday, Aug 03, 2008 at 18:25
And don't forget......no use having a good size cable going to the brakes if you haven't got a good neg return !! Are you relying on a small little wire going from the plug to the chassis ?? Or does the wire only go to the towbar ?? If it does, how do you know you have a good connection from it to the chassis ??
If you must use the chassis as a neg return, make sure the wire from the plug is a good size and make sure the chassis connections are clean metal to metal ??
FollowupID:
585325
Reply By: Member - David T (SA) - Monday, Aug 04, 2008 at 13:43
Monday, Aug 04, 2008 at 13:43
The guy who fitted
mine said that you do not want the brakes to lock up because then you lose control of the trailer. The idea is to have the trailer assist in stopping you but not be the main braking force. So my Prodigy is set so that it just holds the car on idle. I can feel it assisting when I use the manual over-ride but it definitely does not lock the
wheels. If you were on a steep descent on dirt it is better that the
wheels are still turning.
Cheers
Dave
AnswerID:
318967