Adding oil to an old transport refrigeration unit

[rackrookie]

Most of the time I work on rack systems, but today my supervisor asked me to replace the filter drier of an old light truck thermoking unit. This is the first time I get involved in such transport systems. He hinted me that some oil must be added to the new drier in order to account for the one being lost by discarding the old unit. But how much should that be? Also, why can´t the oil be added to the compressor instead?

[freonguy]

Rackrookie:

Have you ever cut apart a LL drier? You should on occasion to see the state of the system you just pulled the drier out of - how much crud are you REALLY dealing with there.

I have - lots of times - curiosity thing. I have never seen a drier logged with oil UNLESS taken out a system that has major problems and there is sluggish flow through the LL and there is a severe oil return problem - they aren't even oily to the touch. Now an improperly installed suction drier is a bit different story, but that does not seem like your question.

Is he just yanking your chain, or is there something else out there from Thermo-King??

If the level in the compressor sight glass is OK - don't add nothin'!!

[Reefer-Tek]

Rackrookie:

Have you ever cut apart a LL drier? You should on occasion to see the state of the system you just pulled the drier out of - how much crud are you REALLY dealing with there.

I have - lots of times - curiosity thing. I have never seen a drier logged with oil UNLESS taken out a system that has major problems and there is sluggish flow through the LL and there is a severe oil return problem - they aren't even oily to the touch. Now an improperly installed suction drier is a bit different story, but that does not seem like your question.

Is he just yanking your chain, or is there something else out there from Thermo-King??

If the level in the compressor sight glass is OK - don't add nothin'!!

yeah what freon guy said

[Reefer-Tek]

A drier indesent only has the abilty to absorb a couple droplets of moisture at the most, it is always a good preventative manteance to change driers and or compressor oil filters any time the system has been open for service or every two years as a preventive measure.

I have seen drieres blow apart from the inside and contaminate with indecesnt debris through out the whole system. IT PAYS TO SERVICE YOUR DRIERS!!!!!!!!!!!!!!!!!!!!!!!!!!!

[Reefer-Tek]

Most of the time I work on rack systems, but today my supervisor asked me to replace the filter drier of an old light truck thermoking unit. This is the first time I get involved in such transport systems. He hinted me that some oil must be added to the new drier in order to account for the one being lost by discarding the old unit. But how much should that be? Also, why can´t the oil be added to the compressor instead?

I have never heard such nonsense, of adding oil to the drier. the amount of that could possibly become trapped in a drier is quite minimal, and yes if there was a restriction in the drier that may cause some oil to become trapped, none the less, remove the drier tip it and see if oil drains out if so record that amount, then add that to the compressor.

use new compressor oil that is recomended for the specif refrigerant and compressor design.

Regards R-T