no pressure to cab AC unit

[Roadglide117]

I checked my engine AC pressure and it was low. Was not blowing very cold , when it can normally freeze my wife out. I went to add some freon , gained about 5 lbs psi and the it went to zero , guessing a hose blew. I have a 2015 Ventana 4381. Trying to figure out where these AC hoses might be located. Any help will be appreciated. Thank you!

 

[Chuggs]

The compressor is mounted above the alternator on the drive belt, drivers side.

The hoses both connect to the compressor.

The hose goes forward along the left rail past the engine and somewhere near the rear ping tank it crosses to the right frame rail.

The hoses go forward along the right frame rail to the condensor mounted just aft/below the Primary and Secondary Air Tanks...between the steer tires. One hose continues forward and connects to the TXV on the side of the evaporator housing. The other hose connects to the top of the condensor...whilst another hose goes from the bottom of the condensor back up to the frame rail and connects to the Filter Drier mounted in the passenger side of the gen bay. Then another hose from the Filter drier up to the txv.

Here are some steps...

Order a new Filter drier. Replace anytime you open the system

Pressurize the system with dry nitrogen thru your guage set...and use a detecting solution to check every connection and service port. Repair any leaks. If you find none...then you may have to use a sniffer for the evaporator and condensor to locate the problem. Repair or replace.

Put in new Filter drier and leak test it with dry nitrogen too.

Once the system is sealed draw
your vacuum.

Put your R134a on a scale and recharge the system. If your condensor is up front like mine, the decal might say 2.25 lbs...so charge until you have 2.25lbs in the system.

Should work well.

If not you have other issues.

 

[Chuggs]

BTW, sections of the A/C hoses have split loom plastic conduit wrapped around. So, it may not be obvious in some places... Help prevent rubbing.

And I believe a section by the engine has heat shielding wrap too.

 

[Roadglide117]

The compressor is mounted above the alternator on the drive belt, drivers side.

The hoses both connect to the compressor.

The hose goes forward along the left rail past the engine and somewhere near the rear ping tank it crosses to the right frame rail.

The hoses go forward along the right frame rail to the condensor mounted just aft/below the Primary and Secondary Air Tanks...between the steer tires. One hose continues forward and connects to the TXV on the side of the evaporator housing. The other hose connects to the top of the condensor...whilst another hose goes from the bottom of the condensor back up to the frame rail and connects to the Filter Drier mounted in the passenger side of the gen bay. Then another hose from the Filter drier up to the txv.

Here are some steps...

Order a new Filter drier. Replace anytime you open the system

Pressurize the system with dry nitrogen thru your guage set...and use a detecting solution to check every connection and service port. Repair any leaks. If you find none...then you may have to use a sniffer for the evaporator and condensor to locate the problem. Repair or replace.

Put in new Filter drier and leak test it with dry nitrogen too.

Once the system is sealed draw
your vacuum.

Put your R134a on a scale and recharge the system. If your condensor is up front like mine, the decal might say 2.25 lbs...so charge until you have 2.25lbs in the system.

Should work well.

If not you have other issues.

Thank you,
This is sounding like a job for Gaffeny to figure out if i can't find find a bad hose

 

[Chuggs]

The hoses are pretty robust. Yes, if there is a wear point...I can see an issue...and they are permeable over a long period of time. I would concentrate on the metal. It deteriorates with weather and age. And fittings...o-rings go bad...lots of giggling going down the road. Pressure and temperature cycles.

It's a big job. I have learned, unfortunately, the hard way. Wanted to flush a hose...the fitting on the condenser is a dissimilar metal connection. It ruined the fitting. Didn't habe time to find a repair shop...so a new co densor from Freightliner!!! And had to swage a new elbow #6 fitting onto the hose. They become problem children with age. But all sorted now...and had a six hour drive with 40 degree air blowing on the passenger vent (closest to the evaporator). So, overall happy we won't suffer this summer.