Air Trailer Brakes

[101RRS]

My new truck has the old trailer brake system that has an air/vacuum tank under the rear of the car and a contoller under the dash that is linked into the trucks braking system. The trailer requires a power assist master cylinder that has a air/vacuum hose that plugs into the back of the truck.

Is there any point in keeping this or should I get rid of it and replace it with a more modern electric brake controller. I haven't seen a trailer with a power assist master cylinder for years.

Thanks

Garry

[Lotz-A-Landies]

My new truck has the old trailer brake system that has an air/vacuum tank under the rear of the car and a contoller under the dash that is linked into the trucks braking system. The trailer requires a power assist master cylinder that has a air/vacuum hose that plugs into the back of the truck.

Is there any point in keeping this or should I get rid of it and replace it with a more modern electric brake controller. I haven't seen a trailer with a power assist master cylinder for years.

Thanks

Garry
Garry

There are still a few older caravans and heavier trailers, particularly car trailers out there that can use the vacuum/mechanical or vacuum/hydraulic systems and in fact they are a very good and robust system. They don't require extra alternator power as do multi-axle electric brakes and when the trailer is over 2 tonne the breakaway system is easier*. Generally trailers of over 2 tonne GTM have to have either vacuum or air or electric operated brakes and over-ride operation brakes are not "legally sufficient" when the GTM is over 2 ton. Given that most 109/110 Land Rovers weigh over 1.5 tonne and the tare weight of a car trailer is frequently over 500 Kg then it is probably illegal to tow any long wheelbase Land Rover on most commercially available car trailers.

In short, my opinion is if the vacuum brake system is on the vehicle, it is not doing you any harm why remove it? The reality is that I am intending to fit up dual line vacuum brakes to both of my S2Bs. I have the kits, and have a friend who has a caravan with vacuum/hydraulic brakes.

Fit an electric brake controller as well if you wish. Or if you are sneaky - you can get additional wiring harnesses for the Prodigy electric controller and then swap the controller between vehicles. (Unlike some cheaper controllers, the Prodigy does not need to be leveled into the car.)

Diana

* A 2+ tonne brake-away brake system is required to hold the brakes on for 15 minutes after disconnection from the towing vehicle. On the vacuum system this is supplied by a reservoir tank on the trailer and the 2nd (supply) pipe on the vehicle. In an electric break away system, this requires an additional functioning battery on the trailer with it's own charging circuit from the vehicle. Excluding the NATO plug, how many 8 pin trailer plugs do you know?

[Blknight.aus]

they're a bloody good system...

not quite as good as proper air brakes but IMHO better than some of (but not all) of the electrical systems. for most of the reasons already outlined but with the final addition that if you use the right hitch on the front you can have all in one a vac on demand braking system with an over run brake, a breakaway control AND a parkbrake in the same place. I think they can still be had new if you ask in the right places.

[101RRS]

Thanks Diana/Dave

I thought they were a good system - I will never own a trailer with one and any trailers I am likely to have to tow will have an electric system. Therefore I will fit an electric brake controller but just curious if I should also keep it as well.

The tank etc is at the rear of the truck where I might want to put a second LPG tank later or a petrol long range tank. On a 101 you need a long range tank to drive short ranges:p.

Garry

[Blknight.aus]

If your not going to use it and have something else to go in the place its filling turf it its just going to be somethine else that will collect dust dirt grime water and then lead to rust.

[Lotz-A-Landies]

Thanks Diana/Dave
... The tank etc is at the rear of the truck where I might want to put a second LPG tank later or a petrol long range tank. On a 101 you need a long range tank to drive short ranges:p.
Garry
Garry Can understand that you may want to have an LPG tank and don't know the size of the tank that you have in place.

There are a couple of options: If you have a large reservoir tank and may not ever use it. I have a tank designed to fit in cars, it is about 18" long and about 6" in diameter. This could possibly be fitted elsewhere along the chassis rail or wheel arch and I'll swap it with you if you like.
Remove the system and the Diana Refuse Service will collect it from you and may even pay you scrap value! :D:D

Diana

[Sprint]

this requires an additional functioning battery on the trailer with it's own charging circuit from the vehicle. Excluding the NATO plug, how many 8 pin trailer plugs do you know?this is what the AUX pin is for, usually hooked up to the reversing lights, but how many people do you know of who have reversing lights on a trailer?

when i was working at a place building gooseneck trailers, every trailer and every vehicle that had a gooseneck hitch fitted got wired to use the aux pin on the plug to chage the tailer battery

[101 Ron]

On my defender 130 I regularly tow more than 2.5 tonne.
I use a vacuum break away system.
I was fitted by me even though it is old hat simply because the trailer I use had the system already on it.
THe truth is the electric battery breakaway systems are easier to live with.
The parts to repair the vacuum systems are getting harder to get.
Most brake or trailer places dont want to know about them these days.
Go to PBR direct for parts and the best way to go is factory exchange second hand parts.
MY trailer with the breakaway vacuum brakes can be used as a over ride system behind a normal vehicle as well.
The vacuum system can be mechanical or hydraulic on the trailer.
With a diesel getting enough vacuum to run the system can be a problem.
Yes my trailer has the parking hand brake.
I think only vacuum can offer all this.
Electric is easier to fit and is the current standard in break away systems.

[101 Ron]

My understanding is the break away electric systems will work through the standard 7 pin plug.

[101 Ron]

Photos with my 101 with the boat trailer fitted with vacuum break away over ride brakes, but the 101 is not ,so the trailer can operate as a mechanical over ride.
The next photos is the defender showing the the twin vacuum ports , but a non vacuum trailer.
101stuff2015.jpg - Image - Photobucket - Video and Image Hosting (http://s131.photobucket.com/albums/p299/101Ron/?action=view&current=101stuff2015.jpg)
2007106.jpg - Image - Photobucket - Video and Image Hosting (http://s131.photobucket.com/albums/p299/101Ron/?action=view&current=2007106.jpg)
jayco2005campervanhawk26122007004.jpg - Image - Photobucket - Video and Image Hosting (http://s131.photobucket.com/albums/p299/101Ron/?action=view&current=jayco2005campervanhawk26122007004.jpg)

[Lotz-A-Landies]

My understanding is the break away electric systems will work through the standard 7 pin plug.
Ron

They will BUT.

The problem is that with a greater than 2 tonne GTM trailer with electric brakes the regulations state that the trailer battery MUST BE CONTINUOUSLY CHARGED FROM THE TOWING VEHICLE.

Under ADRs the 7th pin is designated as the reversing light circuit with the other 6 being taken up by earth, tail, stop, L & R flashers and the service brakes. On your own trailer you could delete the reversing lights and use that to charge the battery but you would have to remember if you borrowed or hired a trailer.

The only way you can get the auxilliary power under ADR's is with the 12 pin type and how many people use that. No trailer hire people that I know.

Diana

[101 Ron]

I am of the understanding the modern systems recharge via stop and parking brake circults if required as the gel cell batteries fitted have ample capacity.
Many trailers are running around with a 7 pin plug on a break away electric system legal or not and are being factory fitted that way.

[Lotz-A-Landies]

I am of the understanding the modern systems recharge via stop and parking brake circults if required as the gel cell batteries fitted have ample capacity.
Many trailers are running around with a 7 pin plug on a break away electric system legal or not and are being factory fitted that way.
If your only going to use it for a gel cell battery or even a motor cycle battery you could probably get away with it, although the standard light wiring on my 1985 RRc is pathetic mostly only 2mm including the insulation, so I would not be all that bappy about charging much more than a gelcell.

The other option would be one of those solar trickle chargers with the tail light charge as well.

C Ya

Diana

[Sprint]

whens the last time you saw a trailer with reversing lights?

memory is a bit sketchy on this one but IIRC the flat 7 pin plug will plug into a 12 pin socket

[RonMcGr]

What Diana said :D

"Prodigy electric controller"
Best on the market. I swap mine between the Ford Falcon and Discovery. Both are wired for it and it sits in a plastic cradle in both vehicles.

Cheers,

[Lotz-A-Landies]

Photos with my 101 with the boat trailer fitted with vacuum break away over ride brakes, but the 101 is not ,so the trailer can operate as a mechanical over ride....
Big boat trailers are one area where vacuum mechanical (discs) will always remain the standard. Electric brakes don't like being imersed in water, particularly salt water, all that much.
whens the last time you saw a trailer with reversing lights?

memory is a bit sketchy on this one but IIRC the flat 7 pin plug will plug into a 12 pin socket

Today, my car trailer has them, have you ever tried reversing a trailer at night when the trailer disapears into the gloom?

Yes the 7 pin flat is a part of the design of the 12 pin double row flat.

Diana

[Sprint]

Big boat trailers are one area where vacuum mechanical (discs) will always remain the standard. Electric brakes don't like being imersed in water, particularly salt water, all that much.

Today, my car trailer has them, have you ever tried reversing a trailer at night when the trailer disapears into the gloom?

Yes the 7 pin flat is a part of the design of the 12 pin double row flat.

Diana

yup, thats why everyone i know who tows car trailers has decent reversing lights on thier tow vehicle..... lol

but yes, i can appreciate what you're saying

[101 Ron]

Just get this straight......go to any boat shop and buy a boat and trailer over 2 tonnes and these days you will get four wheel brakes hydraulic disc operated via electric motor,supplying hydraulic pressure .
The eletrohydraulic unit is supplied via gel battery pack.
The battery and electro hydraulic is usually mounted on the draw bar.
The battery is recharged via the trailers electrical plug'
This system is standard on most trailers to 4tonne GVM boat or not..
The reason is cost and easier fitting.
Sorry but go to a trailer retailer and ask for a vacuum break away system and they will not want to know you or say the vacuum system is not advailible any more and the electric system is better.
The fact is vacuum is more expensive and PBR who make the parts know this too.
In fact some of the repair kits are not advaillible any more .
The components are now recommended to be replaced with new components only which are expensive.
Even the NSW RTA are pushing batery electric break away systems.
How do I know this .......I have been looking at up grading the vacuum system on my boat trailer knowing when it sh@ts it self I can not get the parts at a good price.
Boat trailer brakes are a common subject in any boating mag and should be read
Vacuum IS OLD HAT>>>>>FACT

[Lotz-A-Landies]

yup, thats why everyone i know who tows car trailers has decent reversing lights on thier tow vehicle..... lol

but yes, i can appreciate what you're saying
Sprint

I agree with you about good reversing lights on vehicle, however on a car trailer loaded with a big lump of a Land Rover all you get is a technicolour wide screen view of the front of the vehicle on the trailer and nothing behind the trailer. I know people who will turn off the extra vehicle reversing lights so they can see whats going on behind the trailer.

Ron

Yes I agree there will be no big comeback of vacuum systems because, as you said, the electric systems are cheaper to install.

However while I have vacuum systems and the availability of vacuum braked trailers I see no reason to remove the system. That and the intention to buy a vintage caravan with it's vacuum brake system.

Cheers
Diana

[hook]

You could use an Anderson plug for charging a battery on the trailer.

A 7 pin flat on the trailer will fit into a 12 pin on your car.

I have a 12 pin on both my cars and don't run 7 pin falt,s on the car any more.