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Locating Spring Brake Control Valve

August 03, 2012, 03:52:18 pm

I have a 98 U270 34'.

I am working on the installation of the Air Force One system on my coach.  The instruction manual states that I need to tie into the coach's supply air connection at the service relay valve and metered air connection at the service brake relay.  I am having a bit of trouble locating these valves.

Maybe someone here has performed this installation recently and knows what I'm talking about?

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Re: Locating Spring Brake Control Valve

Reply #1 – August 03, 2012, 04:14:41 pm

This will be for the service brakes not the spring brake as the spring brake is your parking brake. The lines from the service brake side of the air chamber goes to the relay valve

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Re: Locating Spring Brake Control Valve

Reply #2 – August 03, 2012, 06:20:18 pm

Red Tractor,

Thanks for the reply. 

From going over the air diagrams, it looks like I can use one of the SPS valves from any of the service brakes and just tie in on both sides of the valve (supply and service) for the lines to the Air Force tank/valve. 

From what I can tell, Freightliner and Spartan appear to have some sort of integrated service and emergency valve, hence the wording that is used.  We have separate valves from what I have seen. 

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