Re: 2003 Slide Seal Issue - Resolved
Reply #25 –
Paul, Sorry you are having a problem with this. I have recently been up in the middle of the night for the same reason. 12 vdc compressor running endlessly. What I found was the unloader solenoid (the brass thing at the bottom of the attached photo) failed to close during the compressor ON cycle. This solenoid is Normally Open (NO). When the compressor starts, 12 volts is applied and the solenoid closes in order to pressurize the system. When the compressor reaches pressure the solenoid opens again to relieve the pressure on the compressor piston so it will start easier next time. There are check valves to prevent losing pressure from the entire system.
In my case when I went out to turn the compressor at 0230 hours, I could hear the air gushing out of the output port of that solenoid and when I put my finger over the port it confirmed it.
All that does not help you solve the problem. Here's what I have done. I replaced a small circuit board located by the compressor relay (photo); that wasn't the problem. Then I replaced the Square D pressure switch ( I knew that was it). Wrong! Lastly, I decided to take apart the Parker particulate filter and unloader solenoid. I found there is a filter in the top of it. It has not been serviced for years. The bowl and the insert at the bottom had hairline cracks. I replaced the filter head from Amazon for reasonable price. The bowl is SPECIAL!! Only available from Foretravel; $97.00. For about $15 I bought a bowl from Amazon, it wouldn't work, but the folks t Parker Pneumatics gave me a part number for an insert that would work for $38. Anyway, I put it all together and the unloader would not close completely. That solenoid from Foretravel is $167 plus shipping. I used a workable solenoid from Amazon for $25. The system is now working correctly.
Long story, hope it helps. Let me know if I can help and what you finally find as your solution
Dick
Topic: 2003 Slide Seal Issue - Resolved