Electrically driven compressor

[Roberts]

I have a problem with my compressor blowing air out of the dipstick hole. I cannot see where it draws in the air in the first place. Does it draw in air via the cooling fan for the electric motor or what? It runs OK & sounds OK but can't reach working pressure. As it has not been used for a long time I suspect the piston rings are seized up. Any of the great brains out there got any better ideas or should I say sensible comments I can't afford a new one due to the government stealing my part of my pension! The compressor runs off a normal 13 amp socket and is the normal el cheapo version on sale under different names. Thanks in advance

Robbie

[Alan Deane]

Stuck one-way valve on the cylinder output causing crankcase compression?

[Fredxx]

Stealing part of your pension? Some of us still have to work and have no pension, and have some of our hard earned money taken away to pay for the likes of satellite TV for those that don't work. You could work as well and actually make some contribution to society.

A model type and number would be useful. It does sound like a lot of blow-by past piston rings. They may fee up over time otherwise I can't see any alternative to a strip down.

[The Natural Philosopher]

or worn rings. Or piston/cylinder.

[newshound]

Worth pouring penetrating oil into cylinder and leaving it to soak, in that case

[Roberts]

When I was due to start work I had an idea where I wanted to work but my father said that job does not carry a pension find a job where you will get a pension at the end of it. I listened to my father (for once!) and got a job with a lot less pay but with a pension.which I had to contribute to. Now people seem to begrudge that! I am now 75 years old with three serious illneses COPD, Insulin dependent diabetes & another which I can't spell but still do voluntary work and with the associated paperwork it is almost a full time job. So is that enough for you. I have also seen combat while in the British/Arab Army Robbie

[Roberts]

Blow-by caused by worn piston rings or cylinder walls, or stuck rings, lack of oil or absence of rings. If you stick some oil into the air intake its quite likely to fix it for a while.

NT This was the reason for me asking, I cannot see where the air is drawn in. The only place seems to be where the air is drawn in over the electric motor which does not sound very probable. Being electricly powered there is no convenient sparking plug hole or carb to squirt it in Thanks NT Robbie

[NT]

A piece of paper should help show where the air goes in. Having it flow over or through the motor is likely.

It probably has some sort of filter on the intake, oil needs to go in after that, so you'll likely need to unscrew something. Hopefully the oil will do a fine job of restoring compression.

NT

[Roberts]

As I said before I can not see where the air is being drawn in. It seems that the only possibility is that it is being drawn in through the electric mtor and into the engine somewhere. I suppose I will have to take the electric motor apart to see how it enters the commpressor. I was trying to avoid that because of lots of cables and various nuts and bolts. After 17 years of retirement I'm a bit rusty (& lazy!) I do understand the 2 & 4 stroke cycle and multicylinder 2 stroke opposed piston diesels Robbie Robbie >

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[Fredxx]

Can you provide a model number and manufacturer? How old is it?

I'm puzzled it's not obvious where the intake is. Is the head removable? I'm starting to wonder what type of compressor it is, and whether it's not of the piston variety. Normally the valves and piping are clearly visible on top!

[The Natural Philosopher]

A lot of compressors are rotary vane

[Fredxx]

To be honest I've only seen smaller vacuum pumps which are rotary vane, and some very large compressors, but not smaller workshop compressors.

It could be that this is a vacuum pump after all with the exhaust gases vented into the "crankcase" but without any further info from Robbie we're all in the dark.

[Roberts]

A piece of paper should help show where the air goes in. Having it flow over or through the motor is likely.

It probably has some sort of filter on the intake, oil needs to go in after that, so you'll likely need to unscrew something. Hopefully the oil will do a fine job of restoring compression.

The saga continues! I have removed the cylinderhead/barrell asembly and I am not much wiser. The air must be drawn in through one of the lugs on the cyl. head I will clean it off and see what I can when it gets lighter tomorrow Robbie

[Roberts]

Many thanks Robbie

[NT]

If you've removed the cylinder head, why dont you put the oil there in the cylinder or equivalent

NT

[Roberts]

If you've removed the cylinder head, why dont you put the oil there in the cylinder or equivalent

NT I did not do that because I wanted the oil to go in at the start of the induction process just incase there were stuck valves. The piston rings were not seized surprise surprise! See note of 29th Robbie