Ac Woes!

Put a new compressor and dryer on my '88w124. Had the system vacuumed and tried to charge with refrigerent. The thing just won't suck. I can get maybe a can in and then it just stops. Thought I should change the expansion valve as the search says to do so too. Anyway, still no suction. Have any of you guys ever put in a brand new rebuild from Mercedes and found that it was bad? The clutch does engage as I can see that the compressor is spining and not just the pulley. It is hot here in Sacramento and I have had it for ideas. I just spent $460 plus 50 for the drier and 37 for the expansion valve and at this point all I have is an expensive idler pulley drat! Any and all help would be greatly appreciated. Help pull me threw this. My wife says "sell it and buy an Explorer". OUCH!

Thanks,

Geoff

[Kebowers]

Have you checked the pressures discharge and suction? You may have a leak and a system full of air. you said 'had it vacuumed'. I recommend holding the vacuum for half an hour pumping all the time. Then block it in and confirm that it is tight no decrease in the vacuum for another 30 min. Then charge liquid in th ehigh pressure side(engine off) until either the correct weight had been added or the pressure balances the can. Then start the engine and continue adding VAPOR to the suction side.