Crank bearing cap blew out on Porter cable air compressor
Porter cable two cylinder D22629 air compressor pump blew out the crank bearing cap. Obviously a pressure buildup in the crank case but what causes this and what do I do to fix it ?
Air Tools & Compressors - Porter Cable
Answers & Comments
Your compressor is sold under various part #s depending on brand name. The link below is the breakdown for ac-0171.
http://www.devilbissparts.com/OilLubeStat%20PDF%20files/ac-0171.pdf. You will notice that there is no vent to release internal pressure. Most brands have a filler/dipstick which is also a vent. As the compressor wears there is a normal increase in crank pressure caused by pressure passing thru the rings. I have seen home made vents installed on the bearing cap. If you are creative you can make one yourself using the same cap or a metal cap (axel bearing cap) that fits the opening. A crankcase vent is a very simple device. A small hole to atmosphere with a bit of oil resistant foam behind to prevent oil from being blown out the hole. Works best when there is a vent tube about a couple of inches long to catch any oil and allowing it to run back down into crank. Remember that there is oil sloshing around inside the pump. Examine several brands of compressors for vent and try to recreate that on yours. One thing in common about vents is that they are usually located pretty high up above the crankshaft. You could also try lowering the cut-out pressure on your compressor to reduce back pressure. Good Luck on your repair.