Front and Rear air pressure

tony lee, thanks for the info. Actually swapped front and rear sending units and the problem moved from front to then rear. Also used just a pressure gauge on front system (old pressure sending unit read 25 lbs, but was really 125 lbs). I'm sure beyhond a doubt It is just a bad pressure switch. Thanks

The gauge and the low pressure alarm should not be directly connected so a faulty pressure switch should not cause the gauge to read low so I would think you did have low pressure and the gauge was reading correctly and the pressure switch was also doing the right thing and warning you that the pressure was low.

Okay, it is me again! To answer wny pat, I have drained the tanks several times in the past two weeks (I bought this coach 2 weeks ago). Thanks for the tip though. To mtrumpet I agree there should have been a noticable air leak sound, but there wasn't. I had a tech come out today and he found a bad pressure switch. I should have the replacement tomorrow and then out on the road we go. Once again thanks to all for your great info. You all have been the best help to this ole newbe georgia boy. You all are tops.

When was the last time you drained the tanks?

If your one gauge is only reading 50 psi, then you would have one heck of an air leak! Simply, air up your coach, then shut it down and step outside and listen. You would/should hear an air leak that would be large enough to keep your gauge at 50 psi. You'd probably hear that even with the engine running.

Having said all of that, and you now say that the problem sort of took care of itself for the time being, I'd say that it's more likely a gauge problem and not the actual air system.

Well, I just went out to try my coach again and everything is working fine. I'm glad it is working, but concerned this will pop up again once out on the road. Oh well I will see........

Could also be a wiring issue, particularly if on a Freightliner chassis. There is a known issue with a "cold solder" joint.

On edit: Here is a recent thread on this issue: http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/26907053/gotomsg/26908455.cfm#26908455

Gauges measure the pressure in the 2 separate systems for your front and rear brakes.

Sounds like you have a leak in the front system.

Not expensive, just very necessary to get it fixed as it is a safety issue.