Electric Brakes now not working well after bearing change

Submitted: Thursday, Jul 18, 2013 at 20:07
ThreadID: 103298 Views:5417 Replies:9 FollowUps:16
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In preparation for the "big trip" starting Sat 27th, I repalced the wheel bearing on my Avan and now the electric brakes barely work even at full power setting. Controller is the Tekonsha and was working perfectly untill I changed the wheel bearings. Park brake works as before locking all 2 wheels, brakes buzz when the slider is pushed but wont slow the trailer. On road test, you can wind up to full and never lock up any wheels at any speed on max. output.

Removed drums and degreased all brake and magnet surfaces just in case I got them greasy putting it all back together. Any thoughts anyone, 8 days till departure, getting a bit tense and annoyed my efforts of prepararation has caused me a greater problem. Grrrrr.
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Reply By: pop2jocem - Thursday, Jul 18, 2013 at 20:35

Thursday, Jul 18, 2013 at 20:35
Have you checked what voltage you are getting to the brakes? Maybe you have disturbed an electrical connection when doing the bearings.
Don't you hate it when this sh---- happens just before you are ready to hit the trail?
Had dramas with the van water tanks the night before we left on our last trip.
Yeah Grrrrrr!

AnswerID: 514974

Follow Up By: Triton man - Thursday, Jul 18, 2013 at 21:06

Thursday, Jul 18, 2013 at 21:06
Good thought there Pop, also in preparation, I painted the entire underside with that plastic, tarry stuff and remember painting over the earth wire where it is secured under the floor and to the frame. I am a dumb ar$$ for that and will redo it tomorrow and also check the voltage with a voltmeter. Yes, I do hate it and next contributoor said not to do it before a BIG trip, but do an easy one after maintenace - a good call.

Sorry to hear about the water tank Pop, I duplicate on water with water gerry's

Thanks heaps for the reply. Will let you know how I get on
FollowupID: 794153

Follow Up By: member - mazcan - Thursday, Jul 18, 2013 at 22:12

Thursday, Jul 18, 2013 at 22:12
hi triton man
are you sure you didn't get any of that tarie stuff on the positive wire because it has moisture in it and clean the earth and check power voltage at the pads as mentioned
ithe tar may be shorting the live power supply and yes grease will cause the pads poor magnetic fields
I had electric brakes on my 1980 viscount when I did the big lap and remember grease causing a problem after I did the wheel bearings 3/4 the way around a lot of rough gravel rds in those days
and yes super cheap and most auto shops do have the brake cleaner in pressure packs not cheap but good
metholated spirits is another option and cheaper just use tissues and only do one or two wipes then get more clean tissue each time the pads will come up spotless I use this method when doing any brake / wheel bearing maintenance jobs doesn't matter if you use the whole box just don't tell the missus
FollowupID: 794162

Follow Up By: Triton man - Saturday, Jul 20, 2013 at 21:14

Saturday, Jul 20, 2013 at 21:14
Bought the brake cleaner and attempted the job in high spirits - alas no change. Runing out of time, will have to get the brake specialist on it. Will fix this problem with a Visa card. WATCH THIS SPACE.

I will reply so as to enlighten everybody. Cant be a winner all the time.

Triton man
FollowupID: 794231

Reply By: Gronk - Thursday, Jul 18, 2013 at 20:38

Thursday, Jul 18, 2013 at 20:38
Can't shed any light on the brake issue, but I never redo bearings just before a big trip...

Always do a small weekender etc before the big one.....gives you time to do any adjustments or make sure no heating issues etc show up..
AnswerID: 514975

Follow Up By: Triton man - Thursday, Jul 18, 2013 at 21:10

Thursday, Jul 18, 2013 at 21:10
Gronk, you probably learnt the hard way like I did. Took the van for a 50 klm hike to seat the bearings and then to re-check wheels. It was b***** obvious at the first roundabout I had no brakes and then started my testing, even went to gravel road trying to lock-up the tyres but to no avail. At least I have 8 days, I am glad it is not departure day tomorrow. Have a lead from Pops on voltage which I will persue tomorrow. Thanks for your wisdom, I am learning slowly
FollowupID: 794154

Reply By: Member - Rob D (NSW) - Thursday, Jul 18, 2013 at 21:06

Thursday, Jul 18, 2013 at 21:06
I had a similar problem with my caravan brakes. You will probably find that there is still a very fine film of grease on the magnets, drums and linings. It is the magnets gripping on the side of the drum that provides the force to the shoes.

Washing in solvents such as petrol will dilute the grease but will not completely remove it. A number of manufacturers make a special brake lining cleaner which should be better than petrol. You could find that you will get a better result from washing everything with hot water and detergent. Once you do this go for a good drive and pull the over-ride brake lever on to get your brakes really hot so that they burn off any residue.

I did this on my caravan and used an infra-red thermometer gun to check that wheels on both sides were braking evenly, that is both sides were getting equally hot.

Good Luck
If you relax at a faster pace you can get more relaxation in for a given time.
Regards Rob

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AnswerID: 514979

Follow Up By: Triton man - Thursday, Jul 18, 2013 at 21:19

Thursday, Jul 18, 2013 at 21:19
Rob D,

I am amazed at the wealth of knowledge out there and that all (like you) are prepared to share their knowledge and experience - Thank You. Yes, that is my thought also but it was getting very late when finished but will definetly get that done tomorrow. Would it be available at Super Cheap or AutoBarn, I used to service an Argo with that which drove by claming a spinning flywheel. Do you have a brand name Rod ?.

Will get back to this forum and advise of my findings, thanks heaps for yours Rob D

FollowupID: 794155

Follow Up By: Member - Rob D (NSW) - Thursday, Jul 18, 2013 at 21:35

Thursday, Jul 18, 2013 at 21:35
I bought my brake lining cleaner at AutoPro as far as I recall, I cannot remember the brand, but I think I had a choice of two different brands. I am sure that Super Cheap would have the same.

I think that the water and detergent will give the best result as the detergent kills the grease. You could try searching the web for advice.

By the way if you can hear the buzzing at the brake drums, then your electrics are probable OK.
If you relax at a faster pace you can get more relaxation in for a given time.
Regards Rob

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FollowupID: 794158

Follow Up By: Triton man - Saturday, Jul 20, 2013 at 21:16

Saturday, Jul 20, 2013 at 21:16

Thanks for input, got me $tuffed, going to a brake specialist this next week. Watch this space for a reply before the weekend. Thanks for you input

Triton man
FollowupID: 794232

Reply By: Ross M - Thursday, Jul 18, 2013 at 21:55

Thursday, Jul 18, 2013 at 21:55
Triton man
The use of brake cleaner spray on all friction related surfaces ie MAGGOTS, drums and linings should eliminate friction issue.

The earths for the magnets should not be earthed to the vehicle as standard. They can be, but a direct, from both earth wires to the trailer plug earth is essential so proper, reliable, trouble free, braking can occur.
The earth of the 7 pin base on the vehicle should have a definite earth to chassis and also definite to battery negative. Any of these which are not making a complete circuit will reduce brake magnet strength, no matter how strong the pulses to the magnets are. Just testing at the vehicle 7pin base is an indicator of Controller performance but it has to get to the coils in the magnets and that all important return to battery for it all to work properly and effectively.

Ross M
AnswerID: 514982

Follow Up By: Triton man - Saturday, Jul 20, 2013 at 21:19

Saturday, Jul 20, 2013 at 21:19

MAGGOTS or magnets, could not get too much joy. Am booking it in to a brake specialist. Will let all know what it was and who was the closest to the problem / solution
FollowupID: 794233

Reply By: olcoolone - Friday, Jul 19, 2013 at 08:33

Friday, Jul 19, 2013 at 08:33
Degreaser is one of the worst things to use on brakes, most degreasers will leave an oily film .... this is to add a bit of protection but also it helps in dissolving grease and oil.

The other problem with degreaser is it can penetrate the brake material compound causing damage.

Best thing to use is proper brake cleaner that has a quick evaporating rate and will remove all oils.

Are you brakes adjusted right and how much drag have you got when you spin the wheels?
AnswerID: 514999

Follow Up By: Triton man - Saturday, Jul 20, 2013 at 21:23

Saturday, Jul 20, 2013 at 21:23
Did all of the above, adjusted brakes, cleaned all parts with brake cleaner and checked other stuff. It will be going to the 'shop' next week, will let you all know via this Forum, what the problem was. Thanks olcoolone

Triton man
FollowupID: 794234

Reply By: MEMBER - Darian, SA - Friday, Jul 19, 2013 at 09:23

Friday, Jul 19, 2013 at 09:23
A film of grease could well be the issue, but you might take heart from the following. My van manufacturer did a 'first free service' on our van's hubs a few years back (4 x 12" HD hubs).... don't know who actually did the work but they grossly over-greased the bearings .... after a few hours of driving to home, I checked the brakes to find virtually nothing there ! The grease oozed out of the back seal and it got into the braking area - all over the magnets and shoes - one real mess. At home, I spent hours cleaning it all up and washed the shoes in degreaser (not ideal of course). The point is, the brakes did eventually come good after a few sessions of manual braking while mobile and getting them quite hot......
AnswerID: 515004

Follow Up By: Triton man - Saturday, Jul 20, 2013 at 21:26

Saturday, Jul 20, 2013 at 21:26

Thanks for the input, I am currently up $hit creek but nothing Visa wont fix at the brake specialist. Will let the forum know by end of week what the f*** it was. = (Fault)]]

Triton man
FollowupID: 794235

Reply By: 2TommyGuns - Friday, Jul 19, 2013 at 09:52

Friday, Jul 19, 2013 at 09:52
Hi... Triton man...
This issue is the mother of all trailer probs because of the nature of the beast, getting electricity with current from one end of your veh to the other, plus the actual mechanical action of the braking mechanism...
A couple of things I would look at in order of ease...

(1) Redo all yur earth fitttings on the chassis, physically remove n clean with course emery n scratch up the contact point on the chassis to shiny new metal reattach terminal and spray with a protectant that leaves an anti rust/corrosion barrier.

(2) Check yur connecting male/female pins for tightness and cleanliness then open them up n check the wires/terminals for corrosion (remembering electricity + water n metal not a good mix) n finally check the tightness of them little screws that secure the wire into the terminal...

(3) Did you readjust the brake shoe clearance? If so that has been found to be a factor as the mechanism needs a proportional amount of clearance to actually activate... If you have adjusted them up try backing them off to where they were when they worked...

(4) If you have disassembled the brake mechanism recheck for correct placement of parts... Also the brake shoes!! The system could be employing a leading and trailing shoe... Looks similar but is different, designed to have a self energizing (jamming) effect, swap em around n suffer the consequences...

(5) I suppose I should have included this one first up but it does require a degree of competency to get accuracy... As close as possible to the magnets measure voltage and current (amps)... The current is the most important, the magnets should be drawing no less than 3 amps possibly more at full tit... Now that's from memory so I will stand corrected on that point...

Good luck n keep us posted... Tommy.
AnswerID: 515012

Follow Up By: Tim HJ61 (WA) - Friday, Jul 19, 2013 at 10:58

Friday, Jul 19, 2013 at 10:58
I'm with 2TommyGuns point #3.

Alko told me the brakes need regular adjustment, and failure to do so will result in poor performance and as per my own experience, the actuator arm will jam behind the brake pad and force it to stay on.

I find them a pain actually, but will refrain from ditching them until I replace a now burnt out magnet.

For TritonMan: Jack up a wheel and spin it whilst someone actuates the controller and see what happens. I doubt the light oils from degreaser are stopping the magnet from gripping the drum.

When you pull it all apart again, remove the magnet from the actuator arm and hold a bit of metal onto it whilst someone actuates the controller. It is an interesting experiment that shows the variable nature of the strength of the magnet. It also shows you how strong the magnet is on full power. Once you have experienced this you will not only be able to figure out if the electrical wiring is okay, you will also be reassured about the nil impact of degreaser residue.

Having said that, brake cleaner is great stuff.


FollowupID: 794173

Reply By: Triton man - Saturday, Jul 20, 2013 at 21:31

Saturday, Jul 20, 2013 at 21:31
Thanks to all contributors. Can't be a winner all the time. Have tried all posted suggestions to no avail. Better half wisely suggested a VISA card will fix it and at this point, I tend to agree. Will call the local brake specialist and try to get it done this week.
i WILL respond byt the end of the week as to how this pans ot so... WATCH THIS SPACE.

Thanks again, you guys are great.

Triton man
AnswerID: 515092

Follow Up By: Triton man - Friday, Jul 26, 2013 at 19:39

Friday, Jul 26, 2013 at 19:39
A SINCERE THANK YOU to all you guys out there. Problem is now fixed. As I said, Iwould get back to this forum to let you know. Turned out it was not what everyone thought, even me. It was adjustment only on the brake pads. We all know from the 'olden days' we removed the rubber at the inside of the drum and with a lever, wound up the brake linings to the brake drum till they were binding then backed them off 1 or 2 'clicks' untill they were not hard on and reasonably free to move. Well, that is for 'other' drum brakes. When you have electric brakes, you back off the linings twelve clicks, yep, 12 clicks. Guy said the linings were great and he backed them off 10 clicks commenting that from that point, they will only get better as linings wear a little more. It seems the magnets need room to move and with inertia, they do there job best at that setting. - so, there you have it.

Being sceptical, I took it for my own test run and found this to be true, brakes are now fine, leave on the Savannah Way tomorrow morning with confidence.

Work performed by Knights Brakes in Cairns $60 plus GST of $6. A good but unexpected result - thanks again guys
FollowupID: 794688

Follow Up By: Tim HJ61 (WA) - Friday, Jul 26, 2013 at 22:30

Friday, Jul 26, 2013 at 22:30
Pleased they are working for you again. I thought it might be the case, adjustment.

Please be aware that what your mechanic has told you is contrary to the Alko instruction manual available at http://www.alko.com.au/uploads/2008/12/Electric_Brake_Handbook.pdf

In this handbook it describes the correct adjustment as:
"A brake clean and adjustment should be carried out between the first 300 to 1000 kilometres and then at the service intervals recommended on Page 8. Located in the back of the brake backing plate is a small opening covered by a protective plug. With the trailer wheels off the ground, rotation of the star wheel, (as shown in the diagram below), will result in correct brake adjustment. With a screw driver rotate the star wheel until the brake drag makes it difficult to turn the wheel. The star wheel can then be turned in the opposite direction to allow the trailer wheel to turn 3/4 to 1 revolution freely when spun."

The handbook is worth downloading, and there is also a video on their website at http://www.alko.com.au/news-info/al-ko-videos/caravan-and-motorhome/electric-brakes/ that shoes the internals and describes how they work.

Your brakes work well now and this is good news. My caution is only that they may need more adjustment than you may expect, and more adjustment than car drum brakes.

Enjoy your trip.

FollowupID: 794700

Follow Up By: Tim HJ61 (WA) - Friday, Jul 26, 2013 at 22:49

Friday, Jul 26, 2013 at 22:49
My apologies Triton Man.

It seems there is widespread confusion over the poor wording of the Alko manual. It seems that the 12 clicks rule is common, and that equates to 3/4 to 1 revolution OF THE STAR WHEEL.

I took it to mean of the ROAD Wheel.

Nevertheless, the Alko manual is still worth downloading and reading.

FollowupID: 794701

Follow Up By: Triton man - Saturday, Jul 27, 2013 at 06:34

Saturday, Jul 27, 2013 at 06:34
Thanks Tim, could not help myself to reply. It is 6:30 am Saturday, leave in 1 hour. Thanks for the link, will get to it later

See Ya

FollowupID: 794706

Follow Up By: Tim HJ61 (WA) - Tuesday, Jul 30, 2013 at 11:06

Tuesday, Jul 30, 2013 at 11:06
In an effort to clarify the confusion over the Alko instructions, I sought clarification from the source - Alko.

Their response is:

"Located in the back of the brake backing plate is a small opening covered by a protective plug.
With the trailer wheels off the ground, rotate the star wheel, until the brake drag makes it difficult to turn the road wheel. (i.e. the road wheel is almost locked up)

The star wheel can then be turned in the opposite direction to allow the trailer (road) wheel to turn 3/4 to 1 revolution freely when spun. (i.e. the brakes can drag slightly but the wheel needs to spin freely for ¾ to one full turn before stopping on its own)"

Their addition to the text in their instruction manual is in brackets and makes it clearer how they expect the adjustment to be done.

FollowupID: 794878

Reply By: PETE WS - Monday, Aug 05, 2013 at 21:13

Monday, Aug 05, 2013 at 21:13
Hi triton man
I had similar problem and have found solution
Reading lots of forums the info can lead you up the wrong path
--wrong size wire--I don't think so when same wire has been used before with no problems
--incorrect brake adjustment has very limited effect on actual brake performance
--installing the axle the wrong way is a possibility but hand brake levers would have to be operated from the rear of the trailer,not likely
--rule out incorrectly adjusted bearings (should be addressed anyway)
--all voltage and current is either there or not(mostly)

I recently purchased a new electic braked axle to replace my unbraked item
Considering I have caravan and tandem trailer fitted with electric brakes by myself that work perfectly with plenty of power on the same vehicle using the same wire off the same roll (fairly light speaker wire) I was quite perplexed when my new axle on single trailer which is wired up exactly the same exhibited problems you describe
To cut a long story short and after lots of testing I decided to do direct comparison/measurment with my other known to be good brakes

It became apparent that there was a larger than normal gap between the edge of the drum and the brake backing plate

After removing the brake drum/bearing hub from one side ,of course the magnet was pushed out to the end of its 'wear' travel by the very light spring doing its job

I popped out the plastic plug at bottom of backing plate and took a measurment to face of magnet that should be well and truly touching the inner flat face of brake drum to backing plate. (approx 65mm)

I reinstalled the drum/hub assembly adjusted bearings and then took similar measurment from backing plate to inner flat face of drum. (approx 80mm)

It would appear that there was a 15mm gap where the magnet and drum would never meet

The magnet must be in contact with the drum for brakes to work

Hand brake operation is not affected by magnets

The axle I purchased was the correct length (face to face)where wheels bolt on but plates that were welded to axle to mount backing plate with four bolts were positioned
Too far from ends of axle

I could have made a spacer and fitted longer bolts to rectify the problem but I'm slack and just took the axle back. Problem solved
AnswerID: 515971

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