Community Forums

Greg Kueck · 07-21-2016, 11:57 AM

I have not been able to locate the a/c orifice tube on my 2000 Imperial 350 Cummins. Any help would be appreciate. Photo would be nice! ha. I've repaved them on cars. What the heck ........... ?

Stretch · 07-21-2016, 12:19 PM

Not sure what you want. There is an expansion valve. It is located up front on the firewall.

Greg Kueck · 07-21-2016, 02:37 PM

Thanks Stretch for replying. I did see the expansion valve. The orifice tube is a small inline filter maybe 3 1/2 to 4" long. I too thought I'd find it near the evaporator core or some where close to the expansion valve!

RamiDav · 07-21-2016, 02:58 PM

I thought a system had one or the other .
I googled orifice tube and on How Stuff Works
found this .

"Some vehicles have an orifice tube rather than an expansion valve, but it serves the same purpose in allowing the refrigerant to expand and the pressure to be lowered before the liquid enters the evaporator. The orifice tube allows refrigerant to flow at a constant rate and has no moving parts, but it can become clogged with debris over time. Systems with an orifice tube automatically turn the AC system on and off to regulate the flow of refrigerant to the evaporator."

So it looks like you probably don't have an orifice tube .

Ray D

Scatterbrain · 07-21-2016, 03:06 PM

Quote:

Originally Posted by Greg Kueck

Thanks Stretch for replying. I did see the expansion valve. The orifice tube is a small inline filter maybe 3 1/2 to 4" long. I too thought I'd find it near the evaporator core or some where close to the expansion valve!

An orifice tube is not a filter, even though it does have a screen to catch debris. As Ramidav pointed out, you either have one or the other.

Greg Kueck · 07-21-2016, 04:52 PM

Scatterbrain I knew they sometimes they collected "stuff" in the system but thought they were some kind of filter.

Ray I didn't know I had one or the other! What does the expansion valve do? Do they go bad? How would I check the expansion valve to make sure it is working? Replace it? ha I appreciate your help.

I had my a/c recharged earlier however it would not get very cold. The compressor kicks on. Called Monaco and they told me 4lbs for the system.

Scatterbrain · 07-21-2016, 05:21 PM

Quote:

Originally Posted by Greg Kueck

Scatterbrain I knew they sometimes they collected "stuff" in the system but thought they were some kind of filter.

Ray I didn't know I had one or the other! What does the expansion valve do? Do they go bad? How would I check the expansion valve to make sure it is working? Replace it? ha I appreciate your help.

I had my a/c recharged earlier however it would not get very cold. The compressor kicks on. Called Monaco and they told me 4lbs for the system.

Expansion valves can go bad, but so can compressors. Do you have a set of gauges to check your high and low side pressures? The first thing to verify is that the system is properly charged by weight. Then you check to see if the compressor and expansion valve are working properly by monitoring high and low side pressures when the system is activated. If the expansion valve is stuck closed then the low side pressures will be too low, often considerably. However if it is stuck open then the pressures could mimic a weak A/C pump, which can be a pain to diagnose.

Greg Kueck · 07-21-2016, 05:43 PM

Thanks Scatterbrain. I plan on having this done by a pro. I'll let you know what we find. Thanks so much for your help.

RamiDav · 07-21-2016, 05:47 PM

There was a discussion a while back on the Yahoo Monacoers
group about A/C and someone reported that after getting
different diagnosis he happened upon an older tech that
took a screw driver handle and rapped the expansion valve
a few times .

Now its working good for several years .

Worth a try .

Ray D

Greg Kueck · 07-21-2016, 05:59 PM

Ha now that's my kind of repair! I have lots of screw drivers!

I just had my radiator recored. I removed it and reinstalled it. I can do that stuff. Not much on a/c . Thanks Ray

walt2137 · 07-22-2016, 12:27 PM

Greg I attached a file that I got from one of our members on this forum that i used to repair my AC and it gives you step by step instructions.

Greg Kueck · 07-22-2016, 08:08 PM

Walt thanks for the information. I have my receiver dryer and expansion valve. It is not always easy to find the parts a person needs. I sure do appreciate irv2 and all the information I have been able to come across. Thanks again Walt

RamiDav · 07-22-2016, 08:48 PM

Greg
If you haven't put an eye ball on the expansion valve
and drier they may be sort of hidden .

On my 03 Windsor the expansion valve is on the front
fire wall but was completely wrapped with that thick
gooey insulating tape and my drier is way up high
in the rear above the differential .
Hope this helps .

BTW I found my parts at my local Parts Plus .
Shocked me when I showed him my old parts
and he walked back with new parts .

Ray D