Compressor not working

[Triumphman]

I've got a 50l Clarke style compressor.
Was working fine until last week.
It now only charges up to about 40 psi then won't raise anymore pressure. It just runs and runs, never getting beyond 40 psi. No external leaks I can find.
I've took the head off, the bore and piston look fine, the rest looks ok, maybe a little dirty.
Not sure what I'm looking for.
The head is getting hot, but it's running for ages so I imagine it would.
Any suggestions?

 

[Mikes]

Non return valve sticking?
Air filter dirty?
Receiver full of water?

 

[Ace Paul]

If you got head off pour diesel in the bores see if floats away.

If leaking you would hear it. See how much one way valve is from agents

 

[Triumphman]

Air filter is ok.
Could be non return valve, where would that be? In line somewhere or in the head?
Never drained the receiver, should try that too.

 

[Triumphman]

If you got head off pour diesel in the bores see if floats away.

If leaking you would hear it. See how much one way valve is from agents

If the diesel drains away then the rings/piston/bore are deceased?

 

[BrokenBiker]

If the diesel drains away then the rings/piston/bore are deceased?

Yes

 

[Triumphman]

Yes

I guess a sub £200 compressor won't warrant bore and piston work

 

[BrokenBiker]

I guess a sub £200 compressor won't warrant bore and piston work

Doubtful...can probably just buy the top half for it cheaper

 

[frank horton]

Clark n Machine mart stuff is not so bad if OIL is at the correct level all the time........

 

[norsa]

My Einhell did the same thing. If you run it and put your hand between the starter switch body and the fan grille, is there a stream of air? mine has. Changing the switch will hopefully fix that, theyre not expensive.
Nick

 

[angellonewolf]

Air filter is ok.
Could be non return valve, where would that be? In line somewhere or in the head?
Never drained the receiver, should try that too.

hold on am i reading this right ?

you never drained the tank of any water ?

 

[Triumphman]

Rarely used it and not had it long, so probably ought to. Only used it to inflate tyres until recently

 

[roofman]

Air filter is ok.
Could be non return valve, where would that be? In line somewhere or in the head?
Never drained the receiver, should try that too.

Normaly just on top of the tank,tank feed pipe goes to it 1st....my money is on this being the culprit too

 

[angellonewolf]

Rarely used it and not had it long, so probably ought to. Only used it to inflate tyres until recently

get in to a good habit of it had one at work when i started there had a message the compresser not working

no one had ever done it for years as a guess the amount of water in the tank and muddy carp thick blocked the darin hole i had to remove the drain plug the hole part and stick metal hanger up there to brake up the stuff to let the water and gunk out

put back together it worked and still to this day but dont sound wrong but also not right was just lucky

 

[indykid]

Non return valve sticking?
Air filter dirty?
Receiver full of water?

The non return valve between pump and receiver sticking wouldn't give these symptoms. It would cause issues with the unloader valve once the switch cut out and could cause issues trying to leave the receiver charged for any length of time, but it would have to get to pressure first.

If it can charge to 40psi, it's not blocked enough to be causing an issue I wouldn't expect.

Receiver full of water would cause it to fill to pressure very quickly as it's equivalent to having a very small receiver, but it should be filling to its normal pressure before cutting out, not failing to fill to pressure.

If the motor keeps running, it's not the thermal cutout. It would point to a fairly hefty leak downstream of the pump, the rings on the piston or the reeds in the head are goosed.

If you fill it to 40psi and turn it off, does it lose pressure rapidly or sit at 40psi?

 

[Triumphman]

The non return valve between pump and receiver sticking wouldn't give these symptoms. It would cause issues with the unloader valve once the switch cut out and could cause issues trying to leave the receiver charged for any length of time, but it would have to get to pressure first.

If it can charge to 40psi, it's not blocked enough to be causing an issue I wouldn't expect.

Receiver full of water would cause it to fill to pressure very quickly as it's equivalent to having a very small receiver, but it should be filling to its normal pressure before cutting out, not failing to fill to pressure.

If the motor keeps running, it's not the thermal cutout. It would point to a fairly hefty leak downstream of the pump, the rings on the piston or the reeds in the head are goosed.

If you fill it to 40psi and turn it off, does it lose pressure rapidly or sit at 40psi?

It sits at 40 psi still running, won't gain anymore pressure and keeps running constantly

 

[indykid]

It sits at 40 psi still running, won't gain anymore pressure and keeps running constantly

Ok. What happens when you turn it off? Does it leak down or does it stay at 40psi?

 

[Triumphman]

Stays at 40psi, if I use a tool, it drops and then builds back up to 40 when I stop work.
The motor is running constantly throughout

 

[indykid]

Stays at 40psi

The motor is running constantly throughout

If the first quote is with the motor off, it's reeds or rings (or it's broken the drive arrangement between the motor and pump and that's slipping). If not, what does it do when the motor is switched off?

Is it belt drive or direct drive?

Is it breathing heavily out of the oil dipstick? Pull the dipstick out and put your thumb over the hole and see if pressure builds up quickly. If not, it's not likely rings.

 

[Triumphman]

If the first quote is with the motor off, it's reeds or rings (or it's broken the drive arrangement between the motor and pump and that's slipping). If not, what does it do when the motor is switched off?

Is it belt drive or direct drive?

Is it breathing heavily out of the oil dipstick? Pull the dipstick out and put your thumb over the hole and see if pressure builds up quickly. If not, it's not likely rings.

I'll have a look tomorrow and report back