Understanding Caravan Brakes ( a hobbits tale )

[Snakecharmer]

Before making a complete fool of myself....Again! I firstly would like to mention some of my past experiences in engineering so as confirm my level of stupidity.

 

Built a Racing 2 stroke classic 500cc GP racing motorcycle from scratch.  rebuilt and restored many more including a BMW R75/5 cafe racer project (sold-£13K) -  1971 Series IIA Land Rover; nut and bolt restoration. (sold-£30K) Worked on cars for 45 years. Can drive a lathe,  Restored 2 properties; including a random stone house built in the mid 19th century.

 

I cannot however understand caravan brakes. Not the ones that slow the caravan when driving, that's logical enough, I mean the HAND BRAKE!

 

Here's the rub....

 

Being new to the sport we had our first trip to a site in Hawick, Scottish Borders for two nights last week. No problems there!  Decided to book a further two nights at a site in Berwick Upon Tweed and was allocated a pitch on a slight slope.

 

Procedure was:- Unhitch caravan from the car, apply handbrake and engage motor mover.  Remove handbrake and reverse caravan into position for levelling.  Raised jockey wheel height to accommodate for and aft and then placed a ramp under front offside wheel ( on the left looking from the front ) moved the caravan forward onto the ramp to level.  Achieved a satisfactory  position where caravan was now level in both planes.  Applied hand brake and disengaged the mover.  *****! Caravan slews in a clockwise direction and hand brake lever jumps into an otherwise unseen upright position. Several onlookers thinking my caravan has a mind of its own and several comments of 'shouldn't be doing that mate'!  Although, they were all parked on the flat with one chap saying he doesn't use his handbrake, he has a self levelling everything going on.

 

Advice was that if I move the caravan backwards the brake shoes disengage and I need to move it forward several feet for them to re-engage so I can then apply braking.   Impossible manoeuvre as the length of the pitch would not permit this.

 

All that said: Question? If the brakes do not work when the caravan is moved backwards, how does the Breakaway cable apply brakes when the caravan rolls back.  Is it this that would cause the hand brake lever to spring to vertical and stop it in a different (3rd safety mode?)

 

I have just had the caravan serviced and now it is having the brakes checked and is ready for collection.  If it checks out OK, do I need to arm myself with more chocs, use my jack and possibly fit the wheel lock to stop it from moving off without my permission?

 

Finally: Is anyone aware of a guide for parking on a slope?

 

Yee Haw!

 

Members who think I am stupid need not reply!

Edited July 12, 2020 by Snakecharmer

[Tuningdrew]

You are not alone in your confusion!

[Cliff&Jackie]

The handbrake DOES work after reversing but not so well. 

Having used the mover to get into position, I leave it engaged to act as a the brake. It is also then ready for you leaving.

Cliff

[Lost in the wilderness]

Nah. Not stupid. Just not aware of the way it works. 
your caravan brakes have a clever mechanism inside the drum, called the auto reverse mechanism. 
Basically, when you reverse the caravan, the hitch pushes in, thereby activating the brakes, but as you are reversing, it causes the auto reverse mechanism to trip, releasing the brakes, so you can actually reverse. 
Now, the handbrake simply moves the brake rod - the same rod that the hitch head moved. 
If you are on a slope, with the downhill at the rear, then the van will move a few inches, as the auto reverse sets, this also makes the handbrake lever move up to the  very high position you have seen. 
Basically, what you describe is normal operation. 
Personally, I think it is always better to reverse up levelling ramps, for this very reason

[Stevan]

4 minutes ago, Lost in the wilderness said:

Nah. Not stupid. Just not aware of the way it works. 
your caravan brakes have a clever mechanism inside the drum, called the auto reverse mechanism. 
Basically, when you reverse the caravan, the hitch pushes in, thereby activating the brakes, but as you are reversing, it causes the auto reverse mechanism to trip, releasing the brakes, so you can actually reverse. 
Now, the handbrake simply moves the brake rod - the same rod that the hitch head moved. 
If you are on a slope, with the downhill at the rear, then the van will move a few inches, as the auto reverse sets, this also makes the handbrake lever move up to the  very high position you have seen. 
Basically, what you describe is normal operation. 
Personally, I think it is always better to reverse up levelling ramps, for this very reason

Spot on!

To try and put it simply:-

Travelling forwards, compressing the hitch puts the brakes on.

Reversing it doesn't (otherwise you cannot reverse!)

Parked pointing downhill, all simple, the brakes just work.

Parked pointing uphill, the auto reverse gets in the way, the brake initially comes on but the auto reverse allows it to roll back a few inches before it engages properly.

No problem with the breakaway cable, it is designed to work when travelling forwards, but even if the van rolls backwards there is only a delay of a few inches.

If you have a button type brake lever you should always pull it up to the "unseen vertical position" to tension the spring.

 

 

 

 

Edited July 12, 2020 by Stevan

[Snakecharmer]

So if I reverse up a gradient and then also up a ramp for levelling in the same direction I will have a hand brake?

 

When your at the top of the ramp how do you align your wheel to accept the Al-Ko wheel Lock?

 

If I disengage the mover will the caravan not come flying down even faster until the brake shoes decide to work again?

 

Is there a specific distance before the brake shoes engage or is it arbitrary?  The guy at the pitch opposite (on the flat) looked a bit concerned for his car.

 

I don't know if I am being over cautious but this is pretty fundamental and potentially dangerous stuff.  I am not inclined to keep my mover engaged as it cannot be good for the tyres but see this as an only option.  Hand brakes that only work some of the time and not on hills or after you've been going backwards?  Who designs these things?

 

I thought transmission brakes on land rovers were a bit wobbly but at least they only allow it to move a few inches.  Not several feet!  Do the insurance companies know how these things work? ...Or not!

I need to do a drawing and submit it LOL!

Is that your GT40?

 

Edited July 12, 2020 by Snakecharmer

[Stevan]

5 minutes ago, Snakecharmer said:

So if I reverse up a gradient and then also up a ramp for levelling in the same direction I will have a hand brake?

 

When your at the top of the ramp how do you align your wheel to accept the Al-Ko wheel Lock?

 

If I disengage the mover will the caravan not come flying down even faster until the brake shoes decide to work again?

 

Is there a specific distance before the brake shoes engage or is it arbitrary?  The guy at the pitch opposite (on the flat) looked a bit concerned for his car.

 

I don't know if I am being over cautious but this is pretty fundamental and potentially dangerous stuff.  I am not inclined to keep my mover engaged as it cannot be good for the tyres but see this as an only option.  Hand brakes that only work some of the time and not on hills or after you've been going backwards?  Who designs these things?

 

I thought transmission brakes on land rovers were a bit wobbly but at least they only allow it to move a few inches.  Not several feet!  Do the insurance companies know how these things work? ...Or not!

I need to do a drawing and submit it LOL!

It should only be a few inches, but if one wheel is chocked, a few inches at one wheel is a big sideways swing at the ends of a long caravan. The issue only arises when pulling up a gradient not when reversing up.

Best to chock both sides!

Alko wheel locks are a pain, I would not touch one with a barge poll!

[Guest]

12 minutes ago, Snakecharmer said:

When your at the top of the ramp how do you align your wheel to accept the Al-Ko wheel Lock?

 

 

I'm assuming you have a twin axle? If so, you could use the Lock n Load inflatable leveller which I understand makes lining up your Alko lock easier..

 

 

 

 

[macafee2]

 

[Lost in the wilderness]

32 minutes ago, Snakecharmer said:

 

I thought transmission brakes on land rovers were a bit wobbly but at least they only allow it to move a few inches.  Not several feet!

You should not get more than a few inches of backwards movement. 
As Steven pointed out, a few inches on one wheel can translate to several feet of swing at the ends. 
As for Alko locks, on a single axle, I have got pretty good at guessing how far up a ramp I need to go. I use the mover to put the lock in alignment, then place the ramp along side the wheel, so the desired lift is central to wheel. Then drive forwards, slide ramp in behind wheel, then reverse back up the ramp to desired location. Simple but a pain

[macafee2]

I thought the caravan had to be pulled forward so as to disengage the auto reverse brake mechanism.

When you apply the handbrake, the caravan then rolls back a bit, as for this being a good design....... i dont think so particularly when trying to align an Alko wheel lock.

 

macafee2

[Snakecharmer]

Single axle.  Thanks for the video.  I have seen that.  As I explained in my initial post, I understand how that part works.  Its the Hand Brake operation I do not understand.  Why should going backwards disable a hand brake for crying out loudest.

 

  There should be a warning sticker on the hitch to tell you this.  Anyone with an IQ of between 20-150 would assume that when you put the hand brake on something it will stop it from rolling away. Maybe I am below 20?

 

I hope there is someone at Al-Ko reading this and taking note!

 

Incidentally, I park my van at a lock up and reverse in, then I am about a foot away from a barbed fence, the inclination would mean that the thing would  roll backwards in a breeze with a no hand brake-hand brake.  Thank goodness I always put the dreaded Al-Ko wheel lock on!

 

Anyone used one of these?

 

 

Edited July 12, 2020 by Snakecharmer

[Lost in the wilderness]

20 minutes ago, Snakecharmer said:

Its the Hand Brake operation I do not understand. 

There really isn’t much to understand. 
The handbrake operates on the brake rod. If you apply the handbrake when the van is on a backwards slope, gravity will move the van backwards. The auto reverse mechanism will act as if you are reversing, which allows the van to move a few inches as the brakes set into the reversing position. To accommodate this, the handbrake mechanism can move the brake rod further than the hitch coupling can. This enables the brakes to hold the van in this situation, and is why the handbrake lever comes up so high. 
As a feature of the design, it’s not very desirable, but the cost penalty to design it out and incorporate into the build would be unrealistic. 
it’s a well tried , tested and generally reliable system. Even with its Inherent “feature”

[Jiffy176]

Once you are aware of it you can compensate for it when moving. What you say is completely normal though.

The majority of sites we go on, I use the mover now to place the van makes life much easier and it's what I paid for it for.

[DACS]

Prior to the development of auto-reverse caravan brakes you had to get out of the car and swing a reversing latch onto the coupling shaft.  This prevented the hitch from being pushed in and disabled the brakes.  The system worked well but was inconvenient as you had to apply the reversing latch manually.  More inconvenient was that caravanners often forgot to take the latch off again and drove off with no brakes.

As has been suggested, reverse your caravan onto the levelling ramps if possible so that it will tend to roll forwards.  Another easy solution is to use chocks to prevent the caravan rolling.

[Snakecharmer]

Glad I didn't spend £35K on a caravan to be told I needed chocks to stop it from rolling away!

[Lost in the wilderness]

If your concerned about rolling backwards, you can always use the mover to go back. Apply the handbrake, then continue moving back for a couple of inches. Your handbrake will come up near vertical, your mover will probably stall, and your van will not move

[Guest]

40 minutes ago, DACS said:

Prior to the development of auto-reverse caravan brakes you had to get out of the car and swing a reversing latch onto the coupling shaft.  This prevented the hitch from being pushed in and disabled the brakes.  The system worked well but was inconvenient as you had to apply the reversing latch manually.  More inconvenient was that caravanners often forgot to take the latch off again and drove off with no brakes.

As has been suggested, reverse your caravan onto the levelling ramps if possible so that it will tend to roll forwards.  Another easy solution is to use chocks to prevent the caravan rolling.

 

Just like the British Army Sankey trailers. Getting out to remove the latch in heavy rain wasn't desirable, leaving it on and driving carefully was an easy short cut, but then you'd forget after a while that your trailer wasn't being braked. Then, next time you need to reverse you got out to place the latch, only to find it's still on from last time!!

[Snakecharmer]

Thank You Lost in The Wilderness.  That's the answer I was looking for. 👍  Did you find this out by trial and error or did you see it in an Al-ko operation manual?  In my Lunar manual it reads... "Sighting/Unhitching" - If you have reversed, read the notes on page 20...... 😂😂😂😂😂 Page 20 shows a diagram of the 13 pin plug wiring diagram.  Nothing on 19 by the way, or anywhere else for that matter.  Your knowledge on this could be very interesting to everyone, because your the only one I have had contact with so far that seems to have it.  Including my service agent. Thanks again.

 

It all makes sense now.  When i positioned the caravan on the ramp and disengaged the mover the caravan slewed, offside went back off the ramp and nearside came forward. Hand brake lever went vertical.  Just after that, I guy who had been fitting tyres on a van nearby came over and jacked up my caravan with his trolley jack.  Offside wheel was locked in both directions but nearside wheel would rotate only one way (can't remember which?)  I'm learning now.

 

Tomorrow I experiment to find out EXACTLY how many inches I need to go back to lock the hand brake on and be safe.  I will always use chocks as a back up by  the way.

Edited July 12, 2020 by Snakecharmer

[Snakecharmer]

Thanks you for the info on using the handbrake Lost, .  Now I know how to use your technique (Brake on and reverse back until lever goes vertical) I am satisfied I can now park up in any situation safely.  I hope everyone here benefits from your  knowledge. 👍👍👍  I knew I would learn something and get my IQ up to 21!

[Gordon]

17 hours ago, Snakecharmer said:

Procedure was:- Unhitch caravan from the car, apply handbrake and engage motor mover. 

Wrong sequence - you should fully apply the brakes before unhitching by raising the caravan handbrake lever to vertical (thus compressing the spring in order to store energy that will activate the brakes should the auto-reverse mechanism try to release the brake), then raise the caravan front clear of the towball and drive the towcar away. The mover can also be engaged for added security prior to unhitching if you wish, as this too should lock the wheels stationary.

 

[Snakecharmer]

Typo!

 

[Gordon]

1 hour ago, Snakecharmer said:

Typo!

That's something we're all able to do. I didn't mean to jump down your throat

Gordon.

[JohnPat]

Yes! Been there, done that, got the "T" shirt. I've had two "Roll backs" in my time, nearly lost it once on a steep slope only held by the breakaway cable, which turned into a guitar string!! The second time demolished the Bollard, got a big bill for that one from the Caravan Club. 

I am now very, very careful and use wedges when needed.

[Stevan]

25 minutes ago, JohnPat said:

Yes! Been there, done that, got the "T" shirt. I've had two "Roll backs" in my time, nearly lost it once on a steep slope only held by the breakaway cable, which turned into a guitar string!! The second time demolished the Bollard, got a big bill for that one from the Caravan Club. 

I am now very, very careful and use wedges when needed.

That was always a problem with the old button brake handles (pull up, press button and release down). It had to be up to the near vertical position to prevent backwards movement even though it felt on at 45°. In this position it would hold forwards but was next to useless backwards.

Not nearly so much of an issue with the modern buttonless handle, (spring up, push down) just a gentle tug and it springs up to 45° and when it begins to roll back, after a few inches it raises itself to the top position as the brakes grab.

Edited July 13, 2020 by Stevan