08 Nissan Pathfinder v6
Hello Scotty, a friend checked my AC clutch by connecting direct power. It did not engage. The system did have a charge. (134a) I pulled out the compressor and am about to install a new one but charging concerns me. The new compressor is suppose to be charged with the proper ammount of pag oil (rear ac) . If I pull a vaccume will the pag oil be affected?
One last if the AC slowly got warm on a long drive but it spins by hand, can it be assumed the compressor ddidnt internally break and cause debris to enter the system? See I can change a compressor but not confident flushing and filling the system. {black}:idontknow: (I feel somewhat confident on the filling) Honestly not to many sites even suggest flushing thought its a good idea probably. What do you think?
If I pull a vaccume will the pag oil be affected?
No.
One last if the AC slowly got warm on a long drive but it spins by hand, can it be assumed the compressor ddidnt internally break and cause debris to enter the system?
No, though it may be OK if it was only the compressor clutch that was bad. You can try examining compressor hose fittings for signs of contamination. When testing whether the compressor turns smoothly by hand be sure you are turning the clutch plate attached to the compressor crank, not the pulley.
However you will probably find that the warranty on the new compressor requires the condenser, expansion valve or orifice tube, and drier to be replaced. Also a good idea to flush out the rest of the system. That's standard procedure since even a small amount of contamination from compressor failure can quickly destroy the new compressor. Additional oil needs to be added when replacing or flushing parts.
When filling the system use pure R134a (no sealers, though dye is OK) with a manifold gauge set to monitor pressures. Use a scale to measure the amount of refrigerant specified by the vehicle manufacturer.
Contamination? I saw what looked like normal dirt coating the compressor connections but nothing to concerning. I did wonder however when I removed the 10 mm bolts they had some dry white chalk like substance near the top. (Where nut is) found that odd. Dismissed it because the car is old?. Wish I took a picture.
thanks for the answer on the pag oil.
I wonder If the system has old oil in it and the new compressor is filled with the exact amount.. Do you think there be to much oil in the system?. And the last big question if I may. Im trying to understand the freon tag on the vehicle. It says requires 1.87 +- 0.11 lbs can anyone make this equation easier for a math illerate to comprehend the exact amount of the charge. Thanks !
Contamination? I saw what looked like normal dirt coating the compressor connections but nothing to concerning.
If you're talking about the outside of the hose connections that doesn't tell you anything about what's going on inside. When the hoses are removed from the compressor check inside the compressor ports and the hose fittings for signs of contamination. Also, the compressor crank should turn smoothly with no internal binding or noises.
If you decide to replace no other parts at least install a new drier along with the appropriate amount of oil. (There should be a specification in the shop manual.) The drier is really supposed to be done any time the system is opened to atmosphere.
I wonder If the system has old oil in it and the new compressor is filled with the exact amount.. Do you think there be to much oil in the system?
There is no way to know how much oil is in the AC system unless it is flushed out and fresh new oil of the correct amount put in. Otherwise it is only possible to come up with an approximation.
New compressors usually don't come with the total amount needed in the AC system, they have just what the compressor initially needs. Some come just with assembly and transport oil and need to be drained and filled the correct PAG oil. (The last compressor I replaced was like that.)
Instructions that came with the compressor should detail the oil situation. If the amount of oil in the compressor is not listed the only way to know would be to dump it out and measure it. (Too little oil will destroy the compressor. Too much will reduce cooling.)
It says requires 1.87 +- 0.11 lbs can anyone make this equation easier for a math illerate to comprehend the exact amount of the charge.
That's not an equation, it's a specification. It's telling you that your AC system ideally uses 1.87 pounds of refrigerant, and you can be 0.11 pounds (1.76 ounces) above or below that figure and still be within specification. That's why you need a scale to measure how much refrigerant you charge in, the amount is critical for proper operation and you can't trust the weight listed on the small R134a cans. (Professionals have an AC service machine where they can just dial in the needed amount and an accurate charge is loaded automatically from a large canister of refrigerant.)
You have to be careful working with air conditioning. It is very easy to do damage or injure yourself. Be sure to wear eye protection, you don't want refrigerant hitting your eyes.
Thanks. So I spin the clutch only and it makes a little noise but not say a grinding. But it's not quiet. I guess when the new compressor gets here i can compair? Also when I dumped the oil I did try to look for metal and used a magnet to see if anything was there i did this while turning the clutch. I think it's safe to say the compressor did not self distruct? Yes thank you on the oil answer and the freon I will use a scale for sure.
I think it's safe to say the compressor did not self distruct?
That's a judgement call that only you can make. I personally would err on the side of caution and do the additional work that I mentioned is S.O.P. when replacing a compressor.