Weird Brake problem

Mar 12, 2017
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Hi I need some help with a weird brake problem.
I have a twin axle Bailey Skorpio caravan which I moved from where it was stored over the winter onto my drive about 3 weeks ago to sort out a few bits and pieces (another couple of leaks on the roof etc).
The van towed back from storage with no issues at all and as usual the brakes felt as if they worked fine.
I parked the van at the bottom of my drive and did the work on the one side I could get to.
After a week or so I puled the van back up the slightly sloping drive so I could get to the other side where it has been for about 2 weeks.
It has been held on the slope on the hand brake as usual.
I finished the work this afternoon and went to drop the van back down the drive.
When I released the hand brake I found that the rear wheel on one side was locked on. The other three were moving OK.
I put the hand brake back on, jacked up the van are removed the wheel from the offending hub so I could get the van moved back down the drive.
I release the hand brake again to gently roll the van back to find the rear wheel on the other side had now locked on.
Looking underneath it looks as if the cables aren't going back on the 2 effected hubs when I release the brake. They are left poking out the front of the balance bar, although I can knock them back in without much effort so I don't think its the cables that have stuck. The fault appear to be in the hub itself.
The hand brake has always come up a ling way (almost vertical when fully on) but the brakes themselves always appear to work ok when towing.
I know that I need to fit new hub nuts when I undo them to take the hubs off but if the shoes are hard onto the drum I don't know how I will get the hub off even if I remove the hub nut.
Is there anything I can do to release the shoes without removing the hubs?
The van is a 1991 van and is in reasonably poor condition from past damp and leaks so I don't want to spend much on it as I am hoping to get a new van in a few months
I am supposed to be using the van this Friday.
Sorry for the long post and thanks in advance.
Richard
 

Damian

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Mar 14, 2005
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You can release the shoes by using the star wheel on the back of each drum.
It is behind a green plug cover at the top of the brake backplate and is operated by using a small flat bladed screwdriver to turn the star wheel inside the back of the drum.

There is an arrow marked next to the hole to show which way to tighten the shoes, turn the star wheel the opposite way !!!

http://www.al-ko.co.uk/edit/files/handbooks/overrun-braking-system-handbook.pdf
 
Mar 12, 2017
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I assume that will allow me to remove the hub and find out why the expander is not returning.

Could it just be that the brakes were not correctly adjusted and so the expander 'over expanded'?

Thanks
 
Jun 6, 2009
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Hi, had the same problem on my lunar few years back, in the end I borrowed a hub puller from my local garage, got the hub off and every thing fell back into place, when I went to my local service shop and explained the problem they said it was a common thing on twin axle vans always the rear wheels, and although not according to manufactures recommendations they put cooper grease on the moving parts / arms of the system . since then I now always pull my van a foot forward after reversing to make sure the brakes are not binding / locked in that position.
 
Mar 12, 2017
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Very interesting information, it is both the rear wheels that are effected on my van as well.

I will try a hub puller (I have one anyway) but I am guessing that as it is a 1991 van there is bound to be a lip on the back of the drum that I will have to drag over the shoes probably damaging them.

The one the other side that I managed to release with the adjusted did have a good amount of copper grease in all the right places, so that didn't stop it locking on.

Will report back how i get on.

Thanks
Richard
 
Jun 6, 2009
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Nextec, The puller I used was a type with a dead weight on a spindle / bar , that was bolted to the hub, the weight when slid down the bar hitting the end of the bar gave a hammering effect, the other type that you wind of may work but this was the type I used, mine also at the time was a 1997 van ,
 
Jul 15, 2008
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I would be very wary of dismantling the brake drums.

There are two issues ........ leaving a hand brake on long term can cause the brake shoes to stick to the drums and fail to release properly.
Solution.........use wheel chocks to secure the caravan.

The other issue is the auto reverse mechanism present in caravan brake drums.
( this mechanism allows a caravan to be reversed when fitted with overrun operated brakes)
The brakes can fail to release if you try and move a caravan backwards with out pulling forwards first.
 
Sep 5, 2016
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Totally agree about leaving handbrakes on, nothing annoys me more that seeing a caravan sited on level ground with the handbrake on, it's not going to go anywhere with the corner steadies down and the wheels chocked, :)
 
Jun 1, 2012
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Reference the comment "handbrake almost vertical" this is correct for many, maybe most caravan systems. Don't adjust as you would a car handbrake. Look at the AL-KO website for the correct procedure.
 
Jul 22, 2014
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Gafferbill said:
I would be very wary of dismantling the brake drums.
Why is that?
There are two issues ........ leaving a hand brake on long term can cause the brake shoes to stick ...The other issue is the auto reverse mechanism present in caravan brake drums.
I'm not clear - are they meant to be reasons for not dismantling? The first one sounds like a reason why you would need to dismantle.
 
Mar 14, 2005
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You may find this:-
http://www.al-ko.co.uk/edit/files/handbooks/overrun-braking-system-handbook.pdf

informative.

It should go without saying, if you are not sure of what you are doing ( competent) then as this is part of the safety critical function of a road vehicle i.e. braking, leave it to a competent person.
 
Apr 6, 2017
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Sounds like the Bowden cables may have rusted and the return springs in the hub can't pull the cables back.
Try reversing the caravan this will cause the auto reverse to release the brakes ( maybe).
The main cause for the cables to rust is the outer plastic sleeve splits and lets water in.
When changing the cables the drums will need to come off so the one-shot axle nut will have to be changed and re-torqued.
 
Jul 15, 2008
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DrZhivago said:
Gafferbill said:
I would be very wary of dismantling the brake drums.
Why is that?
There are two issues ........ leaving a hand brake on long term can cause the brake shoes to stick ...The other issue is the auto reverse mechanism present in caravan brake drums.
I'm not clear - are they meant to be reasons for not dismantling? The first one sounds like a reason why you would need to dismantle.

.............my advice was specific to the circumstance the OP described.
The description indicated that the brakes failing to release was random and unpredictable and they appeared to work normally when the caravan was being towed.
Normally a caravan moves forward after a handbrake release but if the movement after a release is backwards the brakes can fail to release properly especially if it is being moved by hand.

Nextec said:
I release the hand brake again to gently roll the van back to find the rear wheel on the other side had now locked on.

The problem would most likely not occur if the caravan was either moved forward a few feet before reversing or the caravan was reversed down the slope with the towcar.
In such circumstances dismantling a brake drum is not likely to achieve anything.
 
Apr 6, 2017
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I was working on a folding camper with a similar problem. The brakes stuck on when releasing the handbrake but when released and towed the brakes worked ok.
This was caused by the sticking Bowden cables as I described in my other post.
 

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