If you replace the drier then you need to add oil. There's amounts specified somewhere around here (DanG144 can probably tell you off the top of your head).I am about to install a new Sanden compressor on my MKIV. I will also be flushing the condenser, evap, and lines at the same time. The new Sanden compressor comes "pre-charged" with oil and ready for install.
My question is, is the oil in the new compressor adequate for the entire system, or do I need to add more oil? I will be using PAG 46 oil.
Thanks all!
I don't *think* it's an RCV problem, mainly because your low side figures look correct. Your high side is low, imo. At 87F Ambient, high should be close to 191. I guess it is entirely possible that you are at the very front end of RCV failure.I think this might be my problem, but I'm not sure. My A/C is blowing cool but not cold enough, especially now that it's getting hot. When the A/C is on, the A/C clutch is engaged continuously, with no slippage of clutch or belt, and both fans are operational. The high-side pressure is definitely too low; low-side pressure is in the ballpark but may be a bit off from where it should be. I also noticed the "pressure transferring/equalizing" noise (from the evaporator/expansion valve area, passenger side of dash) I hear when the A/C is first turned on is noticeably louder than it used to be.
At 87F ambient, the pressure is 31 low/130 high, and 95 psi with the A/C off (after both sides equalize). A couple weeks ago, at 76F ambient, it was 32 low/105 high; 75 off. The pressure when off seems close to the vapor pressure charts for R-134a, if perhaps slightly low, so I don't think the problem is low refrigerant, but I'm not sure.
Does this sound like a refrigerant control valve problem?
Gig'em Aggies.First post after trolling and learning how to fix the NB for years. Beetle is now in my daughter's possession and was informed upon her return from college the A/C isn't cold. Of course, TDIclub forums are the first place to look and found DanG144's post on the fans. Both fans exhibited the low speed failure. Fixed that with the help of the .pdf - BTW, my fans didn't have a resistor, but instead had a resistive element that didn't fail, but the high speed wire had burnt itself in half going to the element. Anyway, A/C still doesn't work. My low/high pressures with A/C on are 70/120. With the A/C off, the pressures don't equalize and go to 350+/150. So, with those pressures and not equalizing, is that the RCV, Compressor, or Expansion Valve. IDparts is having a 10% sale, so it's financially reasonable to replace compressor, drier, and expansion valve all at once. Bug has 153K, so I'm thinking it's time to replace it all anyway.
Any experienced guidance is appreciated.
I am going through this situation as well.I have read this entire thread today as well as others.
AC has been getting warmer for a few days and pressures are a bit wonky, but not near equal. Low side is a too high (50) and high side was 200. Both fans working fine.
So I am thinking either the clutch is slipping, the RCV is bad, or the expansion valve is stuck wide open.
My real question is whether it is worth trying the RCV on a 230,000 mile compressor or if it is best to spend a couple hundred more on a new compressor. How long can one last?
I am thinking it might be like when I put a regulator and brushes in my Alternator and got another year out of it, but then the bearings went out.
This is a very good point. I also ran into the 24-27 ft-lb that the manual said...and I snapped a head bolt! I went back through the manual. At the beginning, they list 2 different bolt sizes...M6 and M8. The M8 bolts are supposed to be torqued to the 24-27, the M6 bolts are 10 ft-lb (which our compressors have)! Unfortunately in the manual, where it shows the procedure to close the compressor back up, it uses the 24-27 and doesn't list the M6 size torque. I was lucky that one of my local hardware stores actually carried that size and style of bolt so I just replaced them all.Thanks to those who contributed to this thread. I did the RCV fix this weekend and it is working well. Here is my contribution:
DO NOT torque the head bolts to the spec in the Sanden manual! It calls for a step at 14 ft lbs and a finish at 24-27 ft lbs. I can tell you that they will hold 14, but not much more.
Thanks for the clarification. I snapped one off as well, but at this time am running one short. I am sure I stretched the others, so I will schedule a time to replace them all.This is a very good point. I also ran into the 24-27 ft-lb that the manual said...and I snapped a head bolt! I went back through the manual. At the beginning, they list 2 different bolt sizes...M6 and M8. The M8 bolts are supposed to be torqued to the 24-27, the M6 bolts are 10 ft-lb (which our compressors have)! Unfortunately in the manual, where it shows the procedure to close the compressor back up, it uses the 24-27 and doesn't list the M6 size torque. I was lucky that one of my local hardware stores actually carried that size and style of bolt so I just replaced them all.
You should be fine with the old bolts and 1 new one, but if you want the peace of mind replace them if you want. The reason I say this as the OEM bolts are hardened. They have a high tensile strength but VERY little elongation before failure. Ie they will just snap and not neck down/yield before failure. I inspected all my old ones and there is no noticeable elongation or yield. I actually re-used 1 of my old ones because I bought 6 instead of the 7 needed.Thanks for the clarification. I snapped one off as well, but at this time am running one short. I am sure I stretched the others, so I will schedule a time to replace them all.