John Comber Posted September 28, 2013 Share Posted September 28, 2013 Question please to those with knowledge of the Rubery Owen brake system ,our stores trailer has air over hydraulic on the front axle and air / linkage to the rear, there is three line air on the drawbar , service and emergency either side of the towing point and coming centrally from the drawbar the third line which I assume is parking brake. Does this operate the front axle , rear or both on application? Any advise welcomed to assist thanks. Quote Link to comment Share on other sites More sharing options...
single speed Posted January 3, 2015 Share Posted January 3, 2015 Any further info on this please? Quote Link to comment Share on other sites More sharing options...
attleej Posted January 3, 2015 Share Posted January 3, 2015 Dear All, The blue line is the auxiliary. I think that it should operate all the brakes on a trailer. It is quite a complicated subject and it would be worth finding a reference book on the subject. John Quote Link to comment Share on other sites More sharing options...
John Comber Posted January 3, 2015 Author Share Posted January 3, 2015 Thanks John, these old trailers only have two suzies though, emergency and service line, now wondering if they were made for blue line in mind but never installed at a time when most towing vehicles were only two line air ?? Quote Link to comment Share on other sites More sharing options...
hummermark Posted January 3, 2015 Share Posted January 3, 2015 Back in time the ford transcontinental era tractor units had 3 air lines red blue yellow as the norm I believe the blue was back up to the yellow so in theory if you put a variable air supply down the blue breaks should work as if using the yellow. Quote Link to comment Share on other sites More sharing options...
attleej Posted January 4, 2015 Share Posted January 4, 2015 Dear All, The reason why I suggested a ref book is that the subject is complicated AND it is easy to get in trouble. Not least because it is easy for the authorities to check! For instance, if you look at back of Bedford MK / MJ you will see a black brake hose permanently fixed to the vehicle pugged into the 'blue' socket. It is called, I think, the bridge. Its purpose is if a two line braked vehicle / trailer is connected rather than a three line one, the air will come out of the aux socket, through the black hose, and then via a double check valve out through the service yellow palm coupling. The result is that if you operate the aux hand control valve in the cab, the trailer brakes will still be applied as well as the vehicle brakes, (even with a two line trailer). If you are towing a two line trailer with a three line towing vehicle it is important to consider what the blue aux line is doing! IMPORTANT CHECK. With a two or three line air braked trailer, the brakes should apply automatically if the trailer should break away and this is effectively a legal requirement. To test this function fully charge the trailers air tanks. Turn off the shut off valve on the red line and then disconnect the red line palm coupling. The trailer brakes should immediately come on fully. If they do not you MUST rectify the fault. Since the driver can test this functionality at any time, you cannot claim that you did not know fault existed. Next steps. I have an air brake ref book and will see if there is anything that I can usefully scan. John Quote Link to comment Share on other sites More sharing options...
John Comber Posted January 4, 2015 Author Share Posted January 4, 2015 Thanks John, your comments all being correct , getting back to my original question and perhaps expanding more, I am trying to understand the braking system on our trailer as installed but seized so unable for me to practically test. The third line looks capped off beneath the drawbar , this is the same on others I have studied ( so is that that auxiliary line ? ) that aside does the parking brake operate both axles or only one ? a Rubery Owen manual would be the answer! Quote Link to comment Share on other sites More sharing options...
jcbpete Posted January 4, 2015 Share Posted January 4, 2015 john my third line is not capped. if you disconnect the red line all brakes come on . Quote Link to comment Share on other sites More sharing options...
John Comber Posted January 5, 2015 Author Share Posted January 5, 2015 Evening Pete, thanks for that , so I know now what should happen but there must be seizure or foul play in certain valves/ lines, even though we have tried to clean out the system. ( sounds more like an old Scammell than a trailer doesn't it !! ) so warmer evenings and a dose of enthusiasm req'd to move forward . Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.