Glad I was sitting down when I got this news! It has been a LONG time since I serviced the air dryer in the air/hydraulic system.

Midland/Haltex no longer makes the dryer type that was used on the Cummins/Holset air system. Further, Midland/Haltex does not make the service kit for the dryer any longer.

After numerous calls and finally contacting Midland/Haltex tech support (very helpful, courteous) I got some dryer numbers that would replace my obsolete dryer. Almost no one stocks those numbers so shipping comes from KC.

$347.00 plus a $90.00 core, plus tax and shipping well over $500.00!

I am in the process of re-designing the system, I have to be careful because the Cummins/Holset air charging system is not straight forward, those prices are nutz! Will post later after all is settled!

Hmmm, a core charge for an obsolete unit? Something is not right with that. The dryer has no connection to any engine as it is a passive system connected to whatever air compressor is onboard. I would call a truck parts house and see what dryer element is the least expensive because that usually equates to the most common one and then go get that dryer. Also consider any of the bus manufacturers.

Cummins/Holset air charging system

https://www.cbsparts.ca/admin/...%20Dryer%20Guide.pdf

http://www.mwwatermark.com/en_...ir-hydraulic-system/

https://www.amazon.com/dp/prod...BE6/?tag=jenkins1-20

Thanks Doug, I have been all thru both of these Haltex tech notes. The part numbers ending with an "X" are re-manufactured.

Tom, please review the links Doug sent. Clearly the Cummins/Holset compressors require a special dryer or conversion valves to prevent oil from getting into the air system. A standard run of the mill dryer can not be used with Cummins/Holset compressors.

" The E or QE type compressors must be installed with a compatible air dryer so the compressor WILL NOT pass oil into the air system. The compatible dryer must maintain pressure in the discharge line while the compressor is unloaded or an Econ Valve and Check Valve must be used in the system."

Here is where the core charge issue is. My original dryer or refresh components are no longer available. To get a dryer compatible with the Cummins/Holset compressor, I need to get a new or re-manufactured unit. Re-manufactured units are cheaper than new units BUT, because because Haltex re-manufacture these dryers, they want a core back or you will be charged. My original dryer is no longer a valid part number so it will not qualify as a valid core for the newer design!

I have found and gotten information as to how to convert a standard Bendix AD-9 dryer (not a drop in but available locally) to work with my compressor, will require removal of an input check valve and econ valve from my old unit and some change of the plumbing and dryer mounting. Re-man including core charge,$367.00 + tax, new $429.00 + tax.

A drop in Bendix AD-9 modified for use with Cummins/Holset compressors by Bendix is $480.00 + tax and $90.00 core. charge

Talk about mission creap! I have had an increasing amount of oil coming down the right side of the engine. I had suspected the junction of the air compressor nd the power steering pump as that area was unusually wet and very dirty with collected dirt.

Removing the air dryer allowed a closer look and able to clean the area a bit, took a pressure washer to cut thru all that crap. Separated the power steering pump from the compressor and found no evidence of oil between them and the gasket was intact.

However, now I could see the oil pressure sender and it was a solid mass of oil and dirt. Its location was just about right to wet down all that area. I can't start the engine with the pump off so I just ordered a new sender. There are other areas of concern but the sender is so buried it is easier to replace and check it off the list.

The other area is on the back side of the injection pump. They are known to leak around the control shafts that extend thru the injection pump.

New air filter is ready to go back in as soon as I put the oil sender and PS pump back in.

I may address other issues bugging me before heading out early July but depends on time.

I have a local diesel service company that does lots of MH (including Barth's) that might have another option for you to consider. Fischer Diesel Service in Pasadena Texas. Their number is (281)487-7904. They might have the parts you need. I have always had good results.

Thanks Tom, thru Ebay, Amazon and local sources I found what is needed. Just waiting on a couple of things to finish up. Write up to follow up.