• Login or Register Here.
  • Login is located in the upper right corner of all pages.


No announcement yet.

I keep blowing-out the compressor shaft seal

  • Filter
  • Time
  • Show
Clear All
new posts

  • I keep blowing-out the compressor shaft seal

    I am having problems and am in need of some advice as to what maybe the problem. I have blown-out two compressor shaft seals while trying to charge the system. From the beginning of the charge it was difficult to add to the system even when it has been evacuated. I tried to add part of the can to the high-side first, but did not seem to want to go in so I started from the low-side port. It was slow to go in but did and at the end of the second can the shaft seal blows-out. The high-side pressure reached a max at about 210psi while the low-side was about 30psi before the seal let go. This has now happened to me twice any help would be appreciated as to what may be the problem.

  • #2
    Welcome Tim: What is this vehicle would help so please add that and any history of why you are working on it at all.
    Lost without some info like, did it even hold a vacuum for at least 1/2 hour? Might not have or system capacity so little you can't get much in if using 12oz common cans of refrigerant.

    Need to know if you have replaced shaft seal or is this a remanufactured compressor first time attempted would help too.

    IMO, high risk with either. So you did get likely 24 oz in thru low side - should do that was gas only not liquid while running or it could choke it.

    IDK still need more info. Seals are a leak spot more than a blow out item as almost all have a pressure relief failsafe for wild overcharge or over pressure which is much higher than the 30/210 pressure you posted,
    MetroWest, Boston


    • #3
      Make and model of the compressor would be a help. I have no luck replacing seals on some, other I have no problem. Some require a shaft protector when sliding the seal into place. If you don't have all the right tools it can be a nightmare to do.


      • #4
        Internal wear may have made the shaft to fall or rise, renedering shaft seal replacement useless and a waste of money. I suggest replacing the compressor.


        • #5
          The vehicle is a 1988 Honda Prelude 2.0Si with 4-wheel steering and the compressor is a Matsushita/Panasonic NL1300AA4.
          A little history-I replaced the original compressor with a remanufactured one and changed from R-12 to R-134a. After I charged the system it would cool on warm days but shut-off on hot days after running for awhile. A red light would appear on the AC switch indicating that there was a difference in rpms between the crankshaft and compressor that lasted more than 3 seconds. I don't drive the car much so I lived with that condition until this summer when I tried to fix it by adding Freon. The gauges showed the low-side about normal 30psi but the high-side was lower than normal not rising above 150psi. I blew-out the shaft seal the first time. I took both compressors in to be rebuilt and after putting one back in tried to charge and blew the second one.


          • #6
            Oh man - getting lousy info to nothing for new for this car.

            For now just a question since using High Side presumably into a well held vacuum (engine off) would draw in most of a small 12oz can if you played temps, warm can, cool engine.

            Alone not the issue as retrofit fittings can be so misadjusted they totally leak or don't work especially if using the original Schrader pushed by the new fitting or OE Schrader removed using the 134a size alone available that way.

            Reviews on rebuilding these were the lowest of all lows! Not encouraging. In my searching around found it was used in other models totally so all hope for new not lost quite yet.

            Just some memory of assorted Hondas this old up to some a good bit newer the belts were manually adjusted on at least some subject to being left too lose for the light you saw or compressor choked even charging into a running system with can upside down - liquid not suggested.

            Who retrofitted this and was it totally done or just a quick kit? What oil used and was all mineral removed or some left in you can if you used Ester but only holds 5 oz oil total.

            Bit lost and feel for you. Quite a few usually Civics were real happy at less than some standard of 80% max charge of 134a of the known R-12 amount and behaved perfectly at as low as 65%.

            Nacho chimed in that shaft would be a reason if worn new seal or not would be the weak link. Jeez - rebuilders? How much can they really test for pressure which should blow out or in car shut down now thru high pressure switch added many were not.

            One more question - do you know the original failure and why?
            MetroWest, Boston


            • #7
              Yes the system would hold vacuum and when I tried to add thru the high-side and it didn't take any I later thought that the condenser might be the problem. I removed the original Schrader and only use the aluminum 134a adapter valve.
              I did the retrofit and followed the procedure flushing system components and replacing the compressor, receiver/dryer and expansion valve. Then filled with Ester oil containing UV dye.
              The original failure was some years ago and at that time I thought that the pressure switch blew-out spraying oil all over that area. Now I know that the switch would disengage the clutch. So it could very well have been the shaft seal on the original failure.
              What do you think of the idea that the condenser is restricted or partially blocked?


              • #8
                Was engine running when touching high pressure port for charging? Never do that.

                Oil: How much is in this thing? It's very easy to lose track and compressors will choke on it as they can't compress a liquid unknown if it would release pressure or break it in some way perhaps beyond possible repair as a core?

                Is a shaft seal the weakest part to take the "hit" if you follow me? I don't know is the only answer. Oil overcharge would usually puddle at bottom of a condenser the original should if tight blow out or flush out. The HE ones if installed when retrofitted really don't and just toss those like a bad filter or are just a restriction.

                New or remanufactured compressors should/must be turned with oil on bench first many times for the period of time when engaged and NOT charged enough to move oil take that for maybe only a minute or so or burn out right away! Heat or pressure that relief valve would blow oil all over the place and cause the entire job to fail new parts and all. The type of spring loaded pressure relief valves do not always reset to seal nor on time to save anything.

                I'm worried you are overloaded with oil, unlucky with new compressors and your aluminum high side port isn't cooperating with your Acme fitting I've had trouble with and another gauge set works not sure exactly why just poor fit probably.

                It's trouble. A set back puts you back worse than when you started. Been a while since retrofitting now and any if holding a vacuum would liquid charge engine off into vacuum thru high side to be part way there before running it at all which you couldn't.

                IDK - what do you wish to do? I think I'd have that compressor off to see if I can even feel it compress and not sure you can do that while installed on this? Tight in there as many are and don't think you can go thru the wheel well on these - been a long time but think it's metal not plastic you can remove to get at it?
                MetroWest, Boston