Brakes that break!

[Caprinut]

Just back from our first big trip- Adelaide to Echuca to Newcastle, and then back via Canberra, to Swan Hill and home.
Great trip and caravan worked well except....

The brakes on one wheel were running very hot on a prelim shake down trip before we left ( this is a brand new axle delivered complete with electric brakes fully assembled and simply bolted on by myself.) To ensure all was well I took it to a electric brake specialist business close-by and paid $135- to have them check it over. They adjusted and assured me all was OK
Well all the way to Echuca it ran hot as hell on one wheel so I disconnected the electrics and towed it without brakes until there. Booked a on-site specialist to fix it and he removed the hub, found nothing wrong (according to him) and told us to RELAX as everything was 100%. He had spent his entire career specializing in bearings and brakes he informed me. Paid him a further $120- and tried to relax as we went onwards with our trip. Before Parkes we had to do a roadside repair as the same wheel was now smoking (pulled hub off and the wires were charred and springs snapped with heat fatigue
Took it into Parkes to the repair yard and paid a further$360- to have a complete backing plate and shoes and magnet fitted.
Still no-one could diagnose the cause.
Been fine since but my faith in specialists is now kaput. Three goes and still no answers.
Original axle supplier is surprised, and reckons it must have been a dud assembly (Oops

[kiwijim]

Howdy Caprinut,

I know the feeling, nothing worse than paying out big $$$$ then down the road, finding that you still have the same problem.

I am just wondering if the trouble was nothing more than the two wires to the brake magnet on that wheel touching together.

I suppose you will never know now.

There are some mechanics who will go to great expense when they cant find the trouble or if they do,
it's a cheap fix for them and a very expensive one for the customer, I E :- if in doubt, replace the lot.
It does happen.

kiwijim

[Caprinut]

KiwiJim, it sure burns my buns to throw away good money like this. Reinforces my belief that if you want something done, do it yourself!
Interesting thought you had, as we took it to an auto-electrician in Parkes who confirmed equal voltage was going to both wheels. He did say that strange things happen under load so that is still possible to have a short intermittently.
Funny thing was at the caravan repair place the mac said that having too thick a cable conducting power to the brakes can be a problem.
The auto-electrician laughed at that. You cannot multiply 12v with a thicker cable. Shows that the caravan business is populated with failed mechanics. Perhaps there should be a licensing requirement to repair caravans.

[Deleted]

Hi caprinut,
Would you believe I have just had the exact same problem ,
Got an old van and whacked three new axles under it all with new brakes etc etc
Took it for a shake down around the block a few times all was good , because of time constraints I didn't have time for a bit of highway speed
So long story short I had an extremely hot brake about a third of the way to where I was heading this was made apparent when the short circuit light
Came on .
I waited until it had cooled considerably before pulling it apart on the side of the road only to find the whole thing melted.
Now knowing the brake components are totally stuffed I cut the wires to stop the short going on ,and then backed the pad adjuster right off , i then reassembled
The brake in question and charged off down the highway , after a while pulling over to check the temperature once again , to my surprise it was red hot again .
No idea why and as I was nearly there and it was now raining very heavily I pushed on , with only 40 or so Km's to go I thought I would worry about it tomorrow
Instead .
For the return trip I took all the parts of the electric brake off the backing plate and looked for evidence of this dragging brake ,the only thing I could see was that
The handbrake lever had been rubbing on the drum quite hard as it had made a good groove toward the outside of the electro magnet surface inside the drum ,
I think this may have been the cause , I still haven't fixed the problem at this stage but will need a new backing plate and drum and new bearings as well .
Happy trails Greg ?

[Deleted]

, personally I believe that only auto electricians should be qualified to work on electric brake systems due to the safety factor. I'm not saying that owners should not be able to work on their own vans (although I think that's the way things are headed unfortunately) as there are some pretty cluey owners around. Just have a look at all the experience on this forum for example. I think that the mechanic who told the poster above that the large cables caused the problem needs to go back to tech and study Kirchoff's Law and Ohm's Law because he obviously doesn't have a clue.

Cheers,
Ross.

[doublechevron]

Sept 7, 2015 0:55:46 GMT 10 @rossjools said:

, personally I believe that only auto electricians should be qualified to work on electric brake systems due to the safety factor. I'm not saying that owners should not be able to work on their own vans (although I think that's the way things are headed unfortunately) as there are some pretty cluey owners around. Just have a look at all the experience on this forum for example. I think that the mechanic who told the poster above that the large cables caused the problem needs to go back to tech and study Kirchoff's Law and Ohm's Law because he obviously doesn't have a clue.

Cheers,
Ross.

Most owners would care more though .....  I was just fitted a new brake controller to the old tow barge here.... and was most pleased to find all the wiring was already there.  I checked it out as I was fitting the controller ..... and found the "professionally fitted" existing wiring had a conductor diameter of about 1.4mm ........ sigh .... So I had the extra work of removing all the old wiring and replacing it with new.  Beware of the wire rating too.  The "6mm" wire that replaced it only has the conductor diameter of about 2.5mm.

Imagine the voltage drop of 4 electro-magnets trying to draw current through probably 10+metres of massively under-rated wire 

I just made myself a dash housing out of junk from around the yard ( that cost nothing ) and stuck the controller up on the dash where both me and the passenger can readily access it's slide to manually apply the brakes if the sh!t ever hits the fan



seeya,
Shane L.