Very common for the Harrison HT6 compressor to leak at the seam. It is absolutely essential to evacuate the system for a minimum of one hour any time the system needs to be recharged. Also, if the system is left open or discharged for more than an hour or so, the accumulator drier should also be replaced.

 

I'm replacing my compressor and have had the system open for less than an hour. I assume I still need to vacuum the system, even though nothing in my maintenance book or the instructions that came with the compressor say it needs to be vacuumed. Would something like this do the job... Air Vacuum Pump with R134A and R12 Connectors?

 

Well its better than nothing. But I use a standard 2 stage vacuum pump. You could do a triple evac with it.

Yes, even though the paperwork you have says nothing about evacuating the system, It is a very common normal procedure for doing AC work. Its one of the first things they teach you in school.

 

Air Vacuum Pump with R134A and R12 Connectors
"Air consumption: 4.2 CFM @ 90 PSI"

That's a pretty serious requirement for a compressor. Better make sure it can supply it for at least an hour... continuously. With the money you'll spend on electricity to run the compressor, you could probably buy an evacuator I haven't used or seen one of those venturi vacs since the early 70's, I figured they quit making them years ago.

 

having the air in your system probaly made your compressor leak. having air in the system will have abnormally high pressure and will blow through the seals. also adding to much refrigerant can do the same

 

you can take it to a mechanic shop for about 75 bucks it can be done, with new refrigerant. also add new refrigerant oil.

 

I believe autozone will rent/loan vacuum pumps. (A good 2 stage.)

I have never heard of excess refrigerant or air causing a compressor to leak.
(22 years exp) Bad design and bad o rings cause the leak in the HT-6. The ring that leaks is the body o-ring which is actually on the low side of the compressor.

I believe the system is designed for 450 psi and has a relief valve if the pressures get that high.

 

could it possibly be the ac control box on the dash? that is what other people have been telling me