IF THAT PRESSURE READING IS WITH THE ENG SHUT OFF , IT IS PROBABLY OK, AS THE HI AND LOW SIDE WILL EQUALIZE WHEN THE COMP IS NOT WORKING , CHECK THE LOW SIDE WITH THE ENG IDOLING, IT SHOULD BE IN THE RANGE OF 30-40 PSI , LOWER MAY MEAN CHARGING IF IT GOES WAY LOW OR INTO A VACC ON THE LOW SIDE AT IDOL, IT MAY JUST NEED CHARGING ,,BUT BE CAREFUL IT IS VERY EASY TO OVERCHARGE A 134 SYSTEM AND PRESSURES CAN GO VERY HI VERY QUICKLY.. AND BE CERTAIN YOU ARE WEARING GOGGLES , JUST IN CASE THAT STUFF IS A NASTY CHEMICAL.. JERRY