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dragger · 10-02-2011, 01:21 AM

I have a 98 Fleetwood American Eagle with a 325 cummins on a spartan chasis,after a air dryer malfunction I did a rebuild of the dryer which included filters and lower end rebuild kit, by the way this is a haldex pure air plus dryer. Also replaced governor with a new D-2 governor, problem is that dryer dumps air at 30 second intervels, by that I mean from the time dryer starts to cycle finishes its cycle which takes about 15 seconds, no activity for another 15 seconds, then starts the cycle all over. It doesn,t seem the compressor ever stops in a situation like this, which can,t be good. Supply line to governor has pressure, control line from dryer to governor is clear, any help would be greatly appreciated as I am still finding my legs on this diesel pusher thing. Thanks in advance.

Dragger

etcmss · 10-02-2011, 05:33 AM

it seems the air compressor is running too often and can be the setting of the pressure switch or an air leak (bleeds down the air system).
was any of this affected in the rebuild?

4travlin · 10-02-2011, 07:12 AM

Dragger,
Was it loading and unloading prior to your rebiuld? Did your desiccant filter come apart and contamiate your system? If so it is a pain to get everything clean.
Does it build air pressure in your air tanks? How long does it take to get up to pressure?
What type of inlet check valve do you have on your Pure air plus? Did you take it off of the dryer base and clean it? It could be partly stoped up causing a slow build up of air pressure in the tanks and giving the govenor a false pressure sensing causing the governor to osilate.
If you put in a lower rebuild kit (DQ 6020) did you install the star shaped check valve and spring in the bottom outlet in the correct direction?
Hope this gives you some things to look at and you can get going.

dragger · 10-02-2011, 09:35 AM

The part that malfunctioned was what Haldex calls (a turbo saver valve) in other words the star shaped check valve, it came apart which caused a constant air leak, hence total rebuild including filters and bottom end,no filters came apart. Seemed to work fine before malfunction. We have not used coach in a while and all air had leaked out. Yesterday started engine to test a few theories, takes about 5-7 min to build air from 0-120 psi, this was at 5:00 PM, it is now 8:30 AM next day and air pressure is 90 psi. coach is still drivable, but worried i'm going to overwork the compressor.

4travlin · 10-02-2011, 11:49 AM

The turbo valve (part #DQ6031) is not what I am referring to as the star check valve.
The star check valve (proper name outlet check valve part #RN60G), is located under the brass bushing where the discharge air line hooks into the dryer. If you remove the brass bushing the spring should come out 1st, then the check valve. This area needs to be clean. If this area is dirty &/or stuck it can cause the governor to osilate, and loss of air pressure. If you purchased a DQ6020 lower housing repair kit you should have gotten a new spring, check valve and o ring as part of this kit.

dragger · 10-02-2011, 02:17 PM

Yes that check valve was also replaced, I believe all that is together correctly, but maybe worth a secong look, I,m starting to wonder if I got a bad governor even though it is new. thanks for all the input.

4travlin · 10-02-2011, 04:25 PM

Yes it could be a bad governor even if it is new. Was the old one acting up? If it was still working try the old one first to see if you get the same results. Might save you $20 and a trip to the parts store just to see if another one will help. If the old one works then a trip to the parts store is in order.

samert111 · 10-09-2011, 05:10 AM

Dragger,
My dryer (same as your's) was doing the same thing. Turned out to be the Turbo Saver Valve. The rubber coating on the washer type seal that screws on the end of the valve came off and would not seal when the dryer reached 120 PSI and unloaded the compressor.

oakred50 · 10-09-2011, 05:07 PM

dragger mine did the same thing as yours you will need to check the unloader in the comp to see if it is holding pressure when in unload mode remove d-2 and install fitting in between the bolt holes 1/8th inch pipe nipple and pressure up to 100-120 see if it holds it will have to hold along with d-2 and purge valve and line from d-2 to purge valve for the air air comp not to cycle mine was loosing resovoir pressure back down the discharge line of the air dryer the check valve in dryer not stopping the air from going back in to the dryer on trucks there is a check valve at the wet tank that stops the air from coming back down the line and keeping the resovoir pressure in the tank I have only had my motor home about two weeks now and have not had a chance to check out the air plumbing
I removed the spring and star washer at dryer discharge and put an 1/2inch in line check valve and it corrected the comp cycling i dont know if there is a check valve at the air tank or not on mine if your comp is a holset 3558052 assembly no i have the cummins no for unloader parts

dragger · 10-10-2011, 09:42 PM

oakred50,after removing d2 from gov., do you mean to plug it off, or put a nipple on it so that you could pressurize the comp. with another source,(like a leakdown test), to dark and to cold to see what comp. I have,that and work seems to get in the way of getting to the bottom of this. Will keep trying, not ready to give up yet, thanks to all for the input, will keep posted.

oakred50 · 10-10-2011, 11:11 PM

dragger you can pressurize the unloader on the comp by installing a pipe nipple in threaded hole of unloader housing middle hole and appling air pressure need to rig up a gauge or if you have leak down tester that will work also the more that I have thought about it there must not be sufficent volume of air to seat the check vave in the dryer the only difference in the inline check valve and the comp star check valve is the spring pressure inline has more seating pressure I still havent had time to check the plumbing either I dont know what tank the drier discharge line goes to to see if there is a check valve there at the tank to stop air from going back down or a bad check valve not holding pressure

dragger · 10-26-2011, 08:49 AM

Just a little update for those that have helped. Well I thought maybe third time would be the charm, so apart the dryer came, cleaned to within a inch of its life, checked and double checked everything, blew out all passages with air, installed dryer along with new governer. Started the testing, now have a different set of issues, builds air very well, reaches predetermined pressure, compressor unloads, dryer purges with a good blast of air then slows down to a very small amount that just continues to keep blowing out the purge valve. I now have new unloader on the way, so next question is, has anyone ever done this type of repair on a Holset compressor,it does look like you have to drain the coolant before starting as there may be a coolant line that goes to the unloader assembly. Anyway, any help would be great, thanks again in advance.

dragger · 10-26-2011, 06:27 PM

Today I put a inline check valve in place of the star shaped check valve with no help to the problem, will replace unloader valve next to see if this solves problem.

dragger · 11-20-2011, 09:56 PM

32 degrees here in central Washington, and I'm outside working on the motorhome. Just installed rebuilt unloader valve hoping this fixes problem. Fairly easy job between hand warmups at the woodstove. Couple hours later, job done, ready for test as long as motor will start. All seems good, builds air as it should, purges,air stops flowing from purge valve, will keep fingers crossed as I move to next issue, air ride valves. Thanks again to all for the help and input.