defender fitted with air bakes for trailer!

i have a 110 with air brakes fitted for a trailer, with a quick coupler on the back.
i was just wanting to speak with anyone who has this system or has used it before as i dont really understand it and would like to make use of it.

this is an original fitment which im told with was a popular optional extra for 110 sweb trucks

there vacuum powered somehow as they are linked to the vauum pipe and theres a tank under the drivers seat with a hydraulic over air valve bolted under the tub.

im presuming you still need a compressor somewhere in the equation? and that they are for 'power on' brakes?

if anyone can shed some light on how this should be correctly linked up to use with a trailer or any past experience with this system please let me know.

Hi David , was just researching this myself and saw your post , theres this thread..........

http://www.landyzone.co.uk/lz/f7/having-air-brakes-fitted-110-legal-stuff-69866.html

and some more if you search with the forum function on the second row of headers , not the google one , and put in "linked trailer brakes" , at least how I found it .

I have been wondering myself , have seen systems in the US where the trailer seems to link straight into the 4x4s own hydraulic system ...not too sure about that as I never got under to investigate properly . Also have seen various air over hydraulic on UK dodge 50 ex service with some kind of link , also on the non air brake versions . Not too sure how they worked either .

Air compressor over hydraulic (common in 7.5 tonners) would let you have regular acting brakes , unlike straight air which as you know needs the air to get the brake OFF , like the parking brake of 7.5 T's . Or at least the ones I am familiar with .

The system you describe is very interesting , with the tank it sounds like an air-over set up but wheres the compressor ?

I was looking at the US style link-in st up just to make towing safer - if it was something I could build myself I would do it . I have built trailers with over run hydraulic brakes before with a lever acting on a master cylinder but having a booster in there would be nice . I have a very large Roma coachbuilt caravan that tends to take over on the downhills and I would prefer to drive in landrover comfort rather than my old lorries .

They could be either vacuum or air brakes there is a difference!
Simple way to check would be to see if theres pressure or a vacuum in the tank.
I would take a bet theres pressure in there.
All hgv brakes require air to get the park brake OFF, but then require air to put the std brakes on.
Used to be real simple but now with electronics amazingly complicated



Lynall