A fellow tech called and is having an issue that has him and I ahve to admit , me a little baffled. A VOLVO L90E Unit has good pressures, 145/40, unit was vacuumed down after having the drier and expansion valve replaced. The unit was originally diagnosed as having a bad compressor, but he has not replaced the compressor because his pressures are good. The unit will not blow cold(nothing below 70 F). R134A was weighed during installation. Does anyone have an idea of the cause of this?
Clamp the heater lines going to the cab to see if the shutoff valve is working or not that would cause the cab not to cool.
I was having the same problem but at a cost of $1000.00 to come fill it. I went to wal-mart and bought a can of heavy duty 134A with a gauge and put it in myself. It has worked for over 8 months so far !
Hello,was the drier installed the right way?Also check the drain tubes at the bottom of the evaporator core be sure they arent plugge with dirt is the condensor clean,check to see if the fan clutch is working ok,or make sure fan belt are tight.
Your pressures seem a little low.....if you are in Texas I assume temps are usually around 80 degrees. I'd expect a high side of 200 PSI. Rough guess is ambient X2 plus 25-30. So about 190-200. An expansion valve stuck open would cause this problem unless this system uses an accumulator. I'm not sure what they use, but whatever your high side is too low. Just tested a system here Wednesday and it was 65 degrees...our high side was 155-160 or about ambient X2 add 25-30. Hope this helps you
I had problem with some Volvo loaders back in the mid ninty's. The evaporator was'nt sealed very well and hot incoming air would leak around it and blend with the cold air resulting in cool not cold air, but pressures would be normal.
I aggree with gggraham...inTexas for sure the pressures are greater...i do think that u can charge it some more if that is the pressure's u r getting.....work on a few Volvo's in tx...L90's and L150's...good luck:usa:usa
Yeah, I agree, your hi side should be higher than 145 psi while the unit is operating. On a hot day, you should see more like 200 to 250 psi easy for proper cooling. Don't know about Volvo, but most equipment still use a sight glass on top of the dryer, that sight glass is the best way to tell when the system is full of refridgerant.
Hi , there is a parameter in v-cads that can be turned on for increased fan speed when high pressure is reached as felt at the binary switch, two of the four leads at the switch are for this feature, but it has to be activated with v-cads, it could be helpfull , not sure witch parameter it is, you have to get on there and read a bit..