Ball Bearings in Low Side of 134a AC system

[TQ60]

Hard guess what it is but do try to do the "CSI RV" thing and save whatever is in there.

It also could be internals of a hose breaking down.

BTW one can get a conduit pushed from back to front in the frame rail without removing anything so you may be able to use abs or pvc as a pull device to pull in a new hose.

[Dtwallace]

This is something I have never seen happen in an A/C system before. If it is in fact the desiccant beads blocking the fitting end, you can break them up with a punch that will fit loosely into the fitting end. This would save you the expense of a new line and require no cutting.

Be sure you blow your air from the other end, not the end the beads are in to clear the line. This will ensure you don't get beads stuck into another area of the line.

My first thought was you were looking at a filter in this area. Some of the older Fords did put filters in the lines prior to the evap coil and orifice.

GM systems used a (TVX) or called it a throttling valve.

A conduit pushed from back to front in the frame rail without removing anything so you may be able to use abs or pvc as a pull device to pull in a new hose is a great idea as long as you don't have access issues to the securing clamps.

It still may take two or more people if you needed to remove the hose. I don't think though the hose is not without a break, and it should turn into a metal line at some point along the way.

Up dates please, and corrections to my incorrect assumptions.
Good luck

[PushedAround]

Originally Posted by deandec

One for both evaporators next to the engine and close to the Condensers.

One for the rear evaporator in the bedroom cabinet just before that expansion valve.

The system is very similar to the diagram on page 16 of this very good manual on auto AC systems.

http://www.ariazone.com/manuals/Auto...g%20Manual.pdf

I weighed both dryers. They are identical in nomenclature and weight at this time.

Thanks. I am well versed in Refrigeration & HVAC but I asked because in most automotive applications, there is only one combination receiver/filter dryer, and that is typically right after the condenser. That's why I asked about the 2. Maybe your system has a separate receiver and 2 filters. Just wondering.

As Dtwallace said, if they truly are desiccant beads, you should be able to crush them easily and blow them out. Years ago, that used to happen with Alco filter dryers, especially when they were subject to vibration. Most others were of the porous core style and usually did not cause clogging.

[TQ60]

Deans unit is like ours and has a condenser at each end si it also has dryer at each end.

[deandec]

Using a power screwdriver I was able to break up the clog of beads. Several blasts from the air compressor appeared to clear the line quite well

I then sprayed a can of aerosol flush through the line to clean it. It did a great job so I will do another flush. The Condensers flushed fine also.

Compresser will be rinsed with PAG46.

My DW was displeased that I forgot the bedroom expansion valve and dryer were no longer installed. So the citrus smell of flush and pag oil chose to land on the bedspread and pillows.

Two steps forward.....one step back.

Waiting on Napa to receive the new parts I need for re-assembly of the system.

Thanks to all for your guidance.

[Dtwallace]

Thanks for the update Dean,

You system is similar to the setups in OTR tractor trucks with sleeper. And the Military vehicles I work with.

I've never seen one on a motor coach and welcome the educational experience. My coach didn't come with a split system like yours.

I'm now planning a serious retro project for the future, and I know it will work wonders going down the road on a hot day.

Thanks again

[TQ60]

Make sure new driers have sight glass to assist in recharging as many no longer have them.

Stand alone site units are used in commercial sites so one could be added as they are an off the shelf part.

[Dtwallace]

TQ, this is an R134a system, site glasses are not needed or reliable to gauge the refrigerant level.

[TQ60]

They still help...One can see what is going on inside.

[Dtwallace]

Most R134a filter dryers have (NO) sight glass.
This is because at approximately 700C refrigerant temperature, the PAG oil will foam giving a false impression of low gas charge.

[PushedAround]

Originally Posted by Dtwallace

Most R134a filter dryers have (NO) sight glass.
This is because at approximately 700C refrigerant temperature, the PAG oil will foam giving a false impression of low gas charge.

Are you saying 700 degrees C or did you mean 70 degrees C?

[Dtwallace]

Originally Posted by PushedAround

Are you saying 700 degrees C or did you mean 70 degrees C?

Pushedaround,

Disregard that temperature and foaming information. It was something new I had just come across and thought I'd share it.

I'm glad you asked because as I research the source of that statement, I can't find anything to back the information up.

I've also noted and used site glasses in 134A systems, and like noted, they do help to see what's going on inside the system.

Thanks for the catch

[Johndale]

Systems with freon 12 you look at the glass for bubbles but freon 134 this does not work because most 134 uses less. A easy way to check if system is fully charged watch the low pressure side hose at the compressor and if it is sweating were the line attaches you are good. This works on both systems. The low side is the large line not the small one. If the freon is low the low side will be warm and if you have to much the compressor will start to sweat. This is the poor mans way to check what the system is doing.


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[PushedAround]

The purpose of the sight glass is to make sure that you have a solid column of liquid refrigerant up to the expansion valve. Bubbles typically mean that you have uncondensed refrigerant (gas) and therefore have reduced flow through the valve and reduced capacity. This usually occurs when a system is undercharged.