Metabo compressor acting up.

[mangocrazy]

I've owned this Metabo compressor for best part of ten years I guess and recently it's started playing up a bit. It's a 50 litre electric compressor and gets occasional use - once or twice a month perhaps. I used it today, got enough pressure in the tank to inflate a couple of tyres, then switched it off. The tyres needed more air than I expected so I went to switch it on again and it just buzzed/hummed at me. It felt rather like a dodgy starter solenoid on a car. Do compressors have starter solenoids?

I left it for an hour or so, switched it on and it fired up fine. I then switched it off, waited a couple of seconds and switched it on again, and it failed to start as before.

Any ideas where the fault would lie?

 

[brightspark]

is it starting from empty every time or doesn't like re starting under load

 

[Member 32799]

Unloader valve working

 

[mangocrazy]

So far it's started OK from empty and with some air in the tank (but not full presssure). The failures have occurred when the compressor has been stopped and restarted soon after.

 

[frank horton]

take the unloader to bits.....it's just stuck....lack of use....
they r very cheap anyway...

 

[mangocrazy]

I wouldn't even know where the unloader is or what it looks like. Where is it fitted?

 

[Seadog]

Neither do we.

A few pictures might help

 

[brightspark]

which one https://www.google.co.uk/search?sou...WGh1wKHdGrAKgQ420oCnoECAoQMA&biw=1280&bih=606

 

[mangocrazy]

I've found this exploded diagram relqating to the Metabo Basic 270 compressor (which mine is). Does this help?

https://www.powertoolspares.com/metabo/023002720010-basic-270-compressor.m/023002720010/spares

 

[Member 32799]

The „B“ hose into 18 , unloader valve is in 18 , it should make a blow off noise when the manual switch on 18 is turned to off

 

[mangocrazy]

Thanks @.. Can that component be dismantled and cleaned, and are there any replaceable service parts in there?

 

[the snooper]

Before you strip it, if you get the hiss when you switch it off the unloader is working, if you don't that's your problem

 

[dobbslc]

Could also be the start capacitor failing and not giving enough shove with the extra load with a full tank.

 

[Seadog]

Could also be the start capacitor failing and not giving enough shove with the extra load with a full tank.

The whole point of the unloader valve is so that it doesn't have to do that.

 

[dobbslc]

If the valve is ok then the capacitor is the next thing I'd look at.
If the valve is not ok it might have been putting extra pressure on the cap and that's how failing.
Still worth thinking about