Compressor Head Gasket Gone

[M@tt]

i noticed tonight my air cut off tool was cutting out constantly and when i checked the compressor it was only making 50psi and running continuously.

when i turned it off i heard a hissing coming from the air filter indicating the HG had gone. I whipped the head off it and sure enough found the picture below.

I just wondered if anything in particular is likely to have caused it to fail? basically I had a feeling yesterday evening that the compressor may have over filled as I remember thinking it was running on for quite a while and when i glanced at the gauge it looked higher then usual (cant remember the exact psi) so i knocked it off manually. I just wonder if too much pressur ein the tank could have blown the gasket?

So on the topic of the cutoff pressure the little black box that sits on the compressor ie this

on mine i find that i get a hissing from it when the compressor first starts up and i can feel air leaking out from it, but then after a while once there's a bit of pressure in the tank the leaking stops. Is this normal behaviour?

cheers

 

[brightspark]

thats normal till it seals on start up .there is a safety valve fitted on the tank at a slightly higher presure than the cutoff switch operates at and would or should blow off if the pressure switch failed . might just be bad luck it went put a new one on and watch the pressure when it builds up and cuts out make sure the safety valve works at corect pressure as well

 

[M@tt]

nice one

cheers BS

i'll get a new HG ordered tomorrow. Nothing's ever simple is it!!

 

[rtbcomp]

The air comes out of the unloading to allow the compressor to get going before it builds any pressure. This type of unloading valve is called a delayed valve, and they usually close at about 20 psi.

The relief valve on mine closes immediately but there is a seperate delay valve on the aftercooler.