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Roland Trombley · 06-22-2022, 04:48 PM

I will remove the braided input line to the dryer after dinner.
Thanks

twinboat · 06-22-2022, 05:26 PM

If the compressor intake is restricted, it can draw oil up past the compressor rings.

A restriction should also lengthen the time it takes to build up air.

Roland Trombley · 06-22-2022, 06:02 PM

I removed the braided line from the compressor to the dryer and it has oil residue in it.

The compressor in this unit is a Holset type compressor, requiring a bypass on the air dryer to prevent the compressor from passing oil. I have the correct air dryer. I suspect that one of the many mechanics who worked on this in Georgia put a check valve in the wrong place.
When I first noticed the oil purging I found through research that one of the mobil mechanics had put the wrong style dryer on, which did not have the appropriate bypass feature. He had also installed a 1/8" 90 degree check valve on the purge line from the governor, which was preventing the purge valve from working.
I removed the check valve and replaced it with an open 1/8" 90, which corrected the failure to purge.

The same mechanic who installed the improper air dryer also replaced the governor.
I am thinking that when he replaced the governor he removed all three of the 90 degree 1/8 fittings at the same time and did not put them back in the same locations, and that one of those is the check valve that I removed to correct the failure to purge.

I have tried running it with the 1/8 check valve both on the opposite end of the purge hose, and on the signal line from the tank, but neither fixed the problem.

Does any of this shed any more light on the issue??

Thanks always for your support

eddndee · 06-22-2022, 07:30 PM

Quote:

Originally Posted by Roland Trombley

I removed the braided line from the compressor to the dryer and it has oil residue in it.

The compressor in this unit is a Holset type compressor, requiring a bypass on the air dryer to prevent the compressor from passing oil. I have the correct air dryer. I suspect that one of the many mechanics who worked on this in Georgia put a check valve in the wrong place.
When I first noticed the oil purging I found through research that one of the mobil mechanics had put the wrong style dryer on, which did not have the appropriate bypass feature. He had also installed a 1/8" 90 degree check valve on the purge line from the governor, which was preventing the purge valve from working.
I removed the check valve and replaced it with an open 1/8" 90, which corrected the failure to purge.

The same mechanic who installed the improper air dryer also replaced the governor.
I am thinking that when he replaced the governor he removed all three of the 90 degree 1/8 fittings at the same time and did not put them back in the same locations, and that one of those is the check valve that I removed to correct the failure to purge.

I have tried running it with the 1/8 check valve both on the opposite end of the purge hose, and on the signal line from the tank, but neither fixed the problem.

Does any of this shed any more light on the issue??

Thanks always for your support

New parts seem to be suspect anymore. I dropped my coach off for an oil change and an oil pressure sensor replacement. After they replaced the sender, they said I still didn’t have oil pressure and suggested a bottom end motor tear down. I made them recheck the digital pressure reading with a mechanical pressure gauge and they were able to determine the new replacement sensor was faulty.

Roland Trombley · 06-23-2022, 05:30 AM

I'm since I am operating with a brand new compressor and dryer, I am contemplating going ahead with our planned 400 mile round trip next week, just to see what happens.

I have already ordered a replacement desiccant cartridge for when I return.

Any thoughts on this??

As I mentioned in an earlier post, there is no evidence of oil or dirt in line from the intake manifold to the compressor intake.

mackwrench · 06-23-2022, 08:33 AM

I'd run it.
I just replaced my spin on filter, $$$ ouch!

Roland Trombley · 06-23-2022, 12:46 PM

This afternoon I again removed the compressor output line from the air dryer input.
There is oily residue, but it is fairly clean oil, not black like the oil in the engine after a few miles.

Then I ran the engine for a few minutes with the compressor line still disconnected.
There was no oil of any kind coming from the hose, just a lot of clean air. I held a sheet of cardboard about 6 inches from the end of the hose and there was no oil.
Maybe I have been seeing residual oil from the bad compressor that was still in the long braided line from the compressor??

Roland Trombley · 07-01-2022, 03:57 PM

I just returned from our 400 mile test trip and the oil problem is still there. Whenever
the air dryer purges it blows a 4 to 6 puddle of oil on the ground. There is also oil splattered on the side of my tow car.
This is the 2nd brand new compressor and correct compatible air dryer, installed by Freightliner.
I have another trip scheduled for the week after next and I don't want to continue to drive it this way. I am wondering if it would be advisable to add an oil separator ahead of the dryer to protect the system.
I'm not getting anywhere having the professionals try to fix it. I have spent a ton of money on this issue already.

TandW · 07-01-2022, 04:11 PM

Sounds like you need a schematic diagram of your system. Wish I could help. Still following your never-ending story, Rollie.

Roland Trombley · 07-01-2022, 04:24 PM

Quote:

Originally Posted by TandW

Sounds like you need a schematic diagram of your system. Wish I could help. Still following your never-ending story, Rollie.

I have been trying to find a detailed schematic that would show how each component is connected, but nothing that I have found has what I need.
I think there is an issue with a missing check valve somewhere.

mackwrench · 07-02-2022, 10:16 AM

3 lines to dryer -

1. Supply from compressor (stainless or copper line/hose)
2. Control from governor (smaller flex aeroquip hose)
3. Delivery to tanks (usually 5/8" green plastic line)

There's no check valve, but a one way valve in the delivery line outlet
On the Haldex pure air dryer the one way valve is accessed but removing the larger fitting the delivery line is threaded into.

There's no check or one-way valve on the supply or control....

I know of no way the oil could get into air system except from supply line.........

If there's enough oil to show spots on your tow car, are you certain that's coming from dryer? It'd take considerably more oil to do that....is there any it's coming from from engine breather crankcase ventilation hose?

Roland Trombley · 07-02-2022, 10:44 AM

https://hosting.photobucket.com/imag...523_134856.jpg

https://hosting.photobucket.com/imag...515_165219.jpg

This gives you an idea of how much oil is purging from my dryer.

Also, here is a photo of my governor. I checked the lines again today and they are all correct.

Roland Trombley · 07-02-2022, 10:54 AM

This morning I removed all of the extra fittings installed by the various techs who worked on it since this all started. This is how it is piped up right now.

That big oil pattern was discharged from my dryer purge port yesterday when we returned from our trip. Fortunately, there is still no sign of oil in the plumbing beyond the dryer

https://hosting.photobucket.com/imag...702_095010.jpg