MAHLE RTI RRC770A - Manual (Page 17)

Page 14
PROBLEMS & SOLUTIONS
On rare occasion the RRC770 may seem to be performing differently or not at all.
Experience has shown that varying operating conditions can affect the performance
characteristics of the RRC770. The temperature of the vehicle A/C System will affect how
the RRC770 performs.
Following are typical problems with explanations of the possible cause and solution.
PROBLEM: My RRC770 worked fine all last Summer. I got it out today for the first service
job this Spring and it is very slow in evacuating the system.
SOLUTION: Today's Spring temperature may be much lower than the average
temperatures during the summer months. Maybe the vehicle was brought in
from outside where the temperature is very low.
The refrigerant in the vehicle will not be under as high a pressure at lower
temperatures and the RRC770 will take longer to draw a vacuum. More
cycles may be required to completely recover the refrigerant.
PROBLEM: I put 5 lbs. of refrigerant into the RRC770 using the Recycle Mode. When I
checked the sight glass on the Internal Cylinder, there was less than 5 lbs.
I lost Refrigerant. The unit must leak.
SOLUTION: Due to temperature changes, some refrigerant may condense into liquid form
and stay in tubes and other components in the circuit preceding the Internal
Cylinder. This is normal and will explain why all refrigerant is not visible in the
sight glass.
PROBLEM: I can not get the RRC770 to draw a vacuum as indicated on the Low Side
Gauge.
SOLUTION: Check Hoses for restrictions.
PROBLEM: When I try to fill the Internal Cylinder from an auxiliary cylinder of clean
refrigerant, the RRC770 is really slow or shuts down.
SOLUTION: The auxiliary cylinder will cool due to the vaporization of refrigerant. This
causes the pressure to decrease.
Use a heat belt to increase the speed of recycling by the RRC770.