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Topic: air dryer purge (Read 783 times) previous topic - next topic

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air dryer purge
have 2001 u270 with 350isc engine and playing with it do not hear the purge cycle does this coach not have an air purge on the dryer

Re: air dryer purge
Reply #1
YES, when the air pressure reaches CUT-OUT PSI (generally around 120 PSI, you should hear the "sneeze"/purge from the air dryer.

But if you don't, first question is how old is your air dryer??

Re: air dryer purge
Reply #2
...first question is how old is your air dryer??
2nd question: What do your dash air pressure gauges indicate when driving down the road?  (highest pressure, lowest pressure)

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Re: air dryer purge
Reply #3
Mine is set to cut in at 95psi and out at 125psi.  The gauges will gradually decrease going down the road depending on the type of road-on a straight flat road with no braking they will take quite a while.  On a curvy road with lots of up and...

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Re: air dryer purge
Reply #4
Brett mine goes from 110-130.  Not as much braking at 95.  I do not need the retarder much at the higher air pressure

Re: air dryer purge
Reply #5
sitting at idle here in yard the back gauge reads 128 and the front 105 but no cycling my other coach would cycle at 125 down to 92 and back
guess I need to replace the purge valve

Re: air dryer purge
Reply #6
Brett mine goes from 110-130.  Not as much braking at 95.  I do not need the retarder much at the higher air pressure

Higher air pressure in your tanks slows you down so retarder is not needed?...

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Re: air dryer purge
Reply #7
sitting at idle here in yard the back gauge reads 128 and the front 105 but no cycling
guess I need to replace the purge valve
Brian,

Don't jump to conclusions...yet.  Need more info.  Try a simple...

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Re: air dryer purge
Reply #8
Doug the "cans" on the wheels receive the chassis air.  I think the system has metered flows.  Being fed from a higher pressure reservoir made a noticable increase in my same pedal efforts braking effect.

At 95 to 110 you had to push harder to get...

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Re: air dryer purge
Reply #9
Doug the "cans" on the wheels receive the chassis air.  I think the system has metered flows.  Being fed from a higher pressure reservoir made a noticable increase in my same pedal efforts...


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Re: air dryer purge
Reply #10
Doug everything was done in steps to separate the results. Took years. 

 Meritor disk brakes self adjust with a hard pedal pressure application. See their manual.

The D2 up pressure was first.  Very noticeable.  Everything else worn.

There is a...

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Re: air dryer purge
Reply #11
My brakes improved a bunch when using a new D2@ higher pressures.  The old was 110/85 ish and now it is 125/105.

Re: air dryer purge
Reply #12
Ok, I'm confused.  I thought that the brakes were spring activated.  IOW the springs will lock up the brakes.  Having air pressure releases the brakes by overcoming the springs.  When you press your brake pedal you are releasing air on the cans...

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Re: air dryer purge
Reply #13
Service brakes (brake pedal) is AIR applied.

Parking/emergency brake is SPRING applied, air released.

There are two cans on each rear brake-- one for service brakes, one for parking/emergency brakes.

There is one can on each front brake-- the...

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Re: air dryer purge
Reply #14
Thanks Brett.  All these years I was wrong!  Makes sense now reading this and the other discussion.
See newbies, don't be afraid to ask a question that seems silly to you. 

Re: air dryer purge
Reply #15
OK anybody have a part number for a d2 govenor  had this problem on my other coach

Re: air dryer purge
Reply #16
OK anybody have a part number for a d2 govenor  had this problem on my other coach
There are two ways to approach a mechanical problem on your coach:

1.  Analyze the symptoms and, with some simple...

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Re: air dryer purge
Reply #17
has anyone changed the purge valve on the dryer was told they should be changed every few years to work good but he was also talking like a big truck  if the governor is working but the vavle does not open and close this could be a problem too i...

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  • John44
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Re: air dryer purge
Reply #18
If you mean the brass valve on the side of the dryer, yes,can find it on Ebay.

Re: air dryer purge
Reply #19
Rather than servicing the air dryer (replacing the filters) a very good idea is to replace the dryer with a factory (factory that made it) reman. The factory reman units come with all new valves, heater, etc.

Do this at three years, then at 6...

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Re: air dryer purge
Reply #20
anyone know the dryer on a 350 isc motor 2001 u270 can get a new or reman

Re: air dryer purge
Reply #21
Make and model of dryer should be on a tag on the dryer.

Re: air dryer purge
Reply #22
thanks brett will look now rain has stopped then figuring out the trailer connection prople do alot of different things this coach had a hoopy attatched and seven pin plug guess they put the hoppy in place to do a 4 pin or 6 pin plug they make...

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