cruiseliner64 Posted December 18 Share Posted December 18 Hi guys,The parking brake on the Cruiseliner wont release.Iv checked and rechecked that I have any pipe work that was moved during painting connected properly(took loads of pics as well as marking them)What I have found is Iv no air at all up at the parking brake control valve on the dash.Im wondering where the valve is fed from or any other ideas you might have..... Paul Quote Link to comment https://www.bigmacktrucks.com/topic/76244-more-air-problems/ Share on other sites More sharing options...
Geoff Weeks Posted December 18 Share Posted December 18 Do both air tanks (primary and secondary) have pressure? Quote Link to comment https://www.bigmacktrucks.com/topic/76244-more-air-problems/#findComment-587368 Share on other sites More sharing options...
Geoff Weeks Posted December 18 Share Posted December 18 What type of valving does the truck have, a multi function valve with both red and yellow knobs or individual buttons ? Quote Link to comment https://www.bigmacktrucks.com/topic/76244-more-air-problems/#findComment-587369 Share on other sites More sharing options...
cruiseliner64 Posted December 18 Author Share Posted December 18 Yes all tanks have full pressure but the parking brake is a europian type lever with 3 pipes.As I remember one is a supply pipe and should have air at all tines the other pipes direct that air to valves to release or apply the parking brake depending on lever position.I was wondering where that air is supplied to the lever comes from.The pipes are not colour coded and will require a lot of work to follow them but if I have to I will do it.The dash would need to be partly removed a job Id rather not do this side of Christmas. Paul Quote Link to comment https://www.bigmacktrucks.com/topic/76244-more-air-problems/#findComment-587376 Share on other sites More sharing options...
Geoff Weeks Posted December 18 Share Posted December 18 Ahh, well I don't have a clue on how it is done over there. The British buses used a mechanical hand brake and the Austrian were similar to the US in having a button that pops out on loss of pressure. Quote Link to comment https://www.bigmacktrucks.com/topic/76244-more-air-problems/#findComment-587377 Share on other sites More sharing options...
cruiseliner64 Posted December 18 Author Share Posted December 18 Thats a pity but many thanks for the replys Paul Quote Link to comment https://www.bigmacktrucks.com/topic/76244-more-air-problems/#findComment-587378 Share on other sites More sharing options...
Geoff Weeks Posted December 18 Share Posted December 18 If I had to guess I would say the three are supply, line to brakes and exhaust line to outside the cab. here in the states, the same supply to the trailer supply button is also used for parking brake release Multi fuction valves get a supply from both the primary and secondary air system. But I have no idea how it is done in other parts of the world. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/76244-more-air-problems/#findComment-587387 Share on other sites More sharing options...
cruiseliner64 Posted 22 hours ago Author Share Posted 22 hours ago I meant to come back and report I found the problem.It turned out to be the valve in the picture which was stuffed with debris...Im thinking it was connected to the air pressure problem....... Paul 1 Quote Link to comment https://www.bigmacktrucks.com/topic/76244-more-air-problems/#findComment-587820 Share on other sites More sharing options...
mrsmackpaul Posted 21 hours ago Share Posted 21 hours ago Well I have no good answers as to we're that starts or finishes I have would expect that is a pressure regulator valve and from memory,the only ones I recall seeing are on the transmission for the range change I wonder if it is a built in safety feature that won't allow the brakes to release unless you have enough air for the transmission?? But I have no idea at all Paul Quote Link to comment https://www.bigmacktrucks.com/topic/76244-more-air-problems/#findComment-587823 Share on other sites More sharing options...
cruiseliner64 Posted 13 hours ago Author Share Posted 13 hours ago Yes Paul its a pressure regulator.I know the picture isnt great but the two air tanks in the pic are connected through this valve.the tank on the right feeds air to the tank below the valve.This tank is directly connected to the parking brake lever.I dont have air pressure test equipment but both gauges on the dash showed full air pressure.I removed enough of the dash to follow the three pipes from the lever and found one went to the parking brake control valve on the frame,one went to the trailer brake control and one went to this tank which had no air in it.The only supply connection this tank has is through this pressure regulator.I removed it cleaned it and now everything works perfect..... Paul Quote Link to comment https://www.bigmacktrucks.com/topic/76244-more-air-problems/#findComment-587829 Share on other sites More sharing options...
Joey Mack Posted 9 hours ago Share Posted 9 hours ago Pryor to cleaning the regulator , was air building in 1 tank and not the other even after the 1st tank was filled past 90 PSI? 1 Quote Link to comment https://www.bigmacktrucks.com/topic/76244-more-air-problems/#findComment-587832 Share on other sites More sharing options...
Geoff Weeks Posted 9 hours ago Share Posted 9 hours ago It looks like a pressure protection valve. It will hold off pressure until its setting is reached, then pass system pressure after that. In N-A they are used for air ride and such so a loss in the suspension will not drain the brake tanks below the setting of the valve. Yes, they are known to plug and stick. I have had several and sometimes if a truck or trailer sits for a long time they stick. Good find. Not knowing your system, I wonder if it has a separate tank for parking release and stuff like air ride? The weird thing would be that a loss of pressure in the main (before the valve) would still keep the spring brakes off as the tank after the valve would be isolated. Quote Link to comment https://www.bigmacktrucks.com/topic/76244-more-air-problems/#findComment-587834 Share on other sites More sharing options...
Geoff Weeks Posted 9 hours ago Share Posted 9 hours ago (edited) Bendix pressure regulating valves Here is what I think you have. No pressure regulation, just adjustable hold off until the pressure is reached. Edited 9 hours ago by Geoff Weeks 1 Quote Link to comment https://www.bigmacktrucks.com/topic/76244-more-air-problems/#findComment-587835 Share on other sites More sharing options...
cruiseliner64 Posted 4 hours ago Author Share Posted 4 hours ago 5 hours ago, Joey Mack said: Pryor to cleaning the regulator , was air building in 1 tank and not the other even after the 1st tank was filled past 90 PSI? Yes,after traceing the pipe to that tank I realised the tank(the one under the regulator in the pic)had no air in it.The tank is fed from the tank on the right through the regulator.It was then I took it apart and cleaned it.The gauges on the dash showed 120psi on both circuits..... Paul 1 Quote Link to comment https://www.bigmacktrucks.com/topic/76244-more-air-problems/#findComment-587855 Share on other sites More sharing options...
cruiseliner64 Posted 4 hours ago Author Share Posted 4 hours ago 4 hours ago, Geoff Weeks said: It looks like a pressure protection valve. It will hold off pressure until its setting is reached, then pass system pressure after that. In N-A they are used for air ride and such so a loss in the suspension will not drain the brake tanks below the setting of the valve. Yes, they are known to plug and stick. I have had several and sometimes if a truck or trailer sits for a long time they stick. Good find. Not knowing your system, I wonder if it has a separate tank for parking release and stuff like air ride? The weird thing would be that a loss of pressure in the main (before the valve) would still keep the spring brakes off as the tank after the valve would be isolated. This tank appears to feed the control circuit for the parking brake.It is connected through the parking brake lever to the parking brake control valve on the frame.The tank beside it feeds air to the control valve to fill the brake chambers to release the spring brakes.If there is no air in the tank to the right in the pic the spring brakes wont release no matter what position the parking brake lever is in or what air is in the tank feeding the parking brake lever.The regulator in your picture is the same one as on our truck..... Paul Quote Link to comment https://www.bigmacktrucks.com/topic/76244-more-air-problems/#findComment-587856 Share on other sites More sharing options...
Geoff Weeks Posted 4 hours ago Share Posted 4 hours ago (edited) Ok that make sense. If the main air is lost, the spring brakes will apply regardless of what position the control is in. Edited 4 hours ago by Geoff Weeks 1 Quote Link to comment https://www.bigmacktrucks.com/topic/76244-more-air-problems/#findComment-587860 Share on other sites More sharing options...
cruiseliner64 Posted 1 hour ago Author Share Posted 1 hour ago 2 hours ago, Geoff Weeks said: Ok that make sense. If the main air is lost, the spring brakes will apply regardless of what position the control is in. Yeah thats it in a nutshell..... Paul Quote Link to comment https://www.bigmacktrucks.com/topic/76244-more-air-problems/#findComment-587864 Share on other sites More sharing options...
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