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Topic: Dryer valve purging every minute (Read 2218 times) previous topic - next topic

Dryer valve purging every minute

Hello all,
The dryer valve on our 320 was popping every minute or less at high idle. Not finding any obvious leaks anywhere I rebuilt the old Haldex from stem to stern yesterday.
Wondered if the compressor had a switch/regulator that could be stuck. Or might the high idle be running exceptional volume of air through compressor? Keith at MOT didn't seem terribly alarmed when I explained this to him. Don't want to address any issues on our first trip.
Thanks in advance!      Tom
Tom
1998 U320 40'

Re: Dryer valve purging every minute

Reply #1 –
High idle doesn't put any unusual amount of air through the dryer - less than running down the road in 6th gear, for sure.  Recommend you replace the D2 governor - about $20 at NAPA - see if that fixes it.  If it doesn't, start looking for more complicated causes.  Or see this thread for a similar complaint:

Air Dryer Rapid cycling?
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Dryer valve purging every minute

Reply #2 –
Second the D2 replacement. 
2025 Wanderbox Outpost 32 on F600 Expedition Motorhome
2015 Born Free Royal Splendor on Ford 550 nonslide version  for sale
Former Coaches  covering. 360,000 miles
1999 34 U270
2000 36 U320
2001 42' double slide U320
2018 Jeep Rubicon

Re: Dryer valve purging every minute

Reply #3 –
That's what ours was doing, and it ended up being the dryer - after replacing the governor.
1996 U295 36' WTBI

Re: Dryer valve purging every minute

Reply #4 –
The OP states he just rebuilt the dryer.
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Dryer valve purging every minute

Reply #5 –
Year of coach?  (Can you add it to your sig in addition to the U280?)  Reason I ask is some discussion awhile ago, Pamela and Mike being contributors I believe, of some air dryers with an intermal piston and some o-rings/seals that you would not be able to check with soap bubbles for leaking.  Referenced in the Air Dryer Rapid Cycling thread Chuck and Jeannie linked.  See also BJ Holden's post in that thread if the year/compressor applies.
Learn every day, but especially from the experiences of others. It's cheaper!  - John C. Bogle

2000 U320 36' non-slide / WildEBeest Rescue
2003 U320

Re: Dryer valve purging every minute

Reply #6 –
Tom,

I know you said you have a Haldex dryer, but which one?  Like is it a Pure air plus, (what most U-320's came with) Purest air, or something else? 

If it is a Pure air plus here is a few things to consider.
Did you rebuild the isolation valve with new O rings?
Are you sure you put the piston back in the bottom of the dryer in the correct direction?
If the piston is in correct you need to check and see if you over tightened the Phillips  screw and broke either the seat or piston itself.
Did you put the discharge check valve in with the rubber sealing area pointed in the correct direction  with the spring underneath?


And no it shouldn't be oscillating that often. Was it doing this before you did the rebuild?

Pamela & Mike

Pamela & Mike 97 U 320

"It's not what happens to you, but how you react to it that matters."

Re: Dryer valve purging every minute

Reply #8 –
Yes it was doing it before rebuilding the dryer. There was a very loose tapered spring in the kit. My friend and I both were convinced it didn't apply to pure air plus rebuilds as it was absent when we disassembled.
I will beg my beautiful bride to assist me in updating coach info tonight! This is a 98 320 40' non slide. Double galley layout.
Tom
1998 U320 40'

Re: Dryer valve purging every minute

Reply #9 –
I'm in the process of the same rebuild.
I think that tapered cone shape spring fits under the isolation valve.
1995 U320C SE 40'
Jeep 4x4 Commander - Limited - Hemi
"The Pack"  Yogi and Diesel our Airedales -  Charlie our Boxer/Akita mix. Gone but NEVER forgotten Jake our yellow Lab.
NRA Law Enforcement Firearms instructor - Handgun/shotgun
Regional Firearms instructor for national Armored Transp. Co.

Re: Dryer valve purging every minute

Reply #10 –
Lon,

Here is what your Isolation valve should be, 
http://epi.hbsna.com/Products/Product.asp?msi=0&sid=31408D1463D8452590103F5F5C6069AC&pf_id=KN23500&dept_id=34

The little tapered spring keeps the discharge check valve in place. It's location is in the fitting  where the hose to the wet tank connects to the bottom of the dryer. I don't have a link to show it's location only a hard copy.

Pamela & Mike
Pamela & Mike 97 U 320

"It's not what happens to you, but how you react to it that matters."

Re: Dryer valve purging every minute

Reply #11 –
Quote from: Pamela & Mike –
Lon,

Here is what your Isolation valve should be, 
http://epi.hbsna.com/Products/Product.asp?msi=0&sid=31408D1463D8452590103F5F5C6069AC&pf_id=KN23500&dept_id=34

The little tapered spring keeps the discharge check valve in place. It's location is in the fitting  where the hose to the wet tank connects to the bottom of the dryer. I don't have a link to show it's location only a hard copy.

Pamela & Mike
Thank you so much for all the info. No way I could own a vehicle like this without the forum and it's wonderful members!
Tom
1998 U320 40'

Re: Dryer valve purging every minute

Reply #12 –
Quote from: Pamela & Mike –
Lon,

Here is what your Isolation valve should be, 
http://epi.hbsna.com/Products/Product.asp?msi=0&sid=31408D1463D8452590103F5F5C6069AC&pf_id=KN23500&dept_id=34

The little tapered spring keeps the discharge check valve in place. It's location is in the fitting  where the hose to the wet tank connects to the bottom of the dryer. I don't have a link to show it's location only a hard copy.

Pamela & Mike

Thanks for the picture, they always help!
I still have mine apart, I better get it resembled soon or I will surly forget something.
I still have not found where the turbo saver goes, the hunt is on.
1995 U320C SE 40'
Jeep 4x4 Commander - Limited - Hemi
"The Pack"  Yogi and Diesel our Airedales -  Charlie our Boxer/Akita mix. Gone but NEVER forgotten Jake our yellow Lab.
NRA Law Enforcement Firearms instructor - Handgun/shotgun
Regional Firearms instructor for national Armored Transp. Co.

Re: Dryer valve purging every minute

Reply #13 –
Quote from: Lon and Cheryl –
I still have not found where the turbo saver goes, the hunt is on.

Lon,

Your turbo saver is in the air galley between air inlet (where your isolation valve is screwed in) and the port where you removed the 1/4" hose.
Here is a couple of pics. of a new unit. Your turbo valve is between these 2 points.
Remove the plug my finger is on in the 1st pic. and you will see the end of the turbo valve.

Pamela & Mike

Pamela & Mike 97 U 320

"It's not what happens to you, but how you react to it that matters."
 

Re: Dryer valve purging every minute

Reply #14 –
Big thanks for those pics.
I would have gone nuts looking for that location.
1995 U320C SE 40'
Jeep 4x4 Commander - Limited - Hemi
"The Pack"  Yogi and Diesel our Airedales -  Charlie our Boxer/Akita mix. Gone but NEVER forgotten Jake our yellow Lab.
NRA Law Enforcement Firearms instructor - Handgun/shotgun
Regional Firearms instructor for national Armored Transp. Co.