Running an old 1978 Cat 930 loader. Had some problems earlier in the year with air lines freezing and recently there has been a lot of oil coming out of the tanks when I drain them. In the last few days it has been warmer, but the air tanks won't pressure up. I removed the plug on top of the compressor- it doesn't seem to be pumping out enough air. Also added air brake anti-freeze fluid into the compressor to clear up any oil that was gunked in the lines. The rear tank will pressure up slightly, but not enough to run the brakes, and the front parking-brake tank won't pressure at all. My general question is does the presence of a lot of black, goopy oil in the air tanks mean that the compressor is going out. If so, has anyone used the compressor rebuild kits and how hard were they to use? Thanks.
I may be wrong , but this happend to mine as well , all I do is take the line off and run gas line antifreeze Through it, and has always worked
Oil in the tanks isn't a good sign but it doesn't necessarily mean that the compressor is totally out. It probably needs a compressor but I'd put an unloader kit in it first. That will keep it from building air. Sent from my SPH-L710 using Tapatalk 2
Like 02Dmax said oil in the air system is not good, could also be the govener not working right.
The first thing i would do is connect an alternate air source to he compressor discharge line and pressurize the system that way. Check all your brake valves for leaks at the exhaust ports, etc.It doesnt take much of a leak to exceed the machines compressor output, plus you cant hear the leaks with the engine running.I ran across this recently on an older 821 case. Also cold weather Tends to make the o-rings in the valves leak more than normal.Oh, you may have a carboned up discharge line too.
I have a 980b that did the same thing when I got it 10 years ago. Like you said there was 30+ years of gunk in the entire air system from not draining the condensation/gunk out with no air drier. There were GALLONS of ick that came out when I drained them. I would also connect the feed line to air and see if you can blow the gunk through and out. The worn compressor is your oil problem. And more than likely the air governor and or the disk valves top of the compressor are plugged with sooty oil. Both easy and cheap! Here is a trick. Before shutting down, pump the brakes down to flip the air governor to build air. Then shut down. When you start the governor is in the build air position and will pump. Oh and drain your tanks, drain your tanks, drain tour tanks daily and before it freezes in the fall.
Thanks for all the replies- finally had time to go through the machine today. I started by checking the air brakes line-by-line from the compressor and determined that both the compressor and governor were working fine. The line from the rear tank to the brake pedals was also clear, but the line between the break pedals wasn't passing much air and quite a bit of air came out. Problem ended up being that left pedal had frozen half-open/half-closed instead of opening all the way (most likely due to gunk). I never could find an air leak, so I assume the air was coming out of the air/hydraulic cylinders which I hadn't inspected yet. I pried the pedal back up and both the pedal and brake system are working fine again. Anti-climatic, but better than having to put in a new compressor.
Those fixes are rare but welcome. I've seen that happen on trucks. Sent from my SPH-L710 using Tapatalk 2