I have an airmaster tiger 15/55 compressor which is approximately 12 years old, as far as i am aware it has only been used a couple of times when it was new and then it was stored until now. When the compressor is turned on the motor fires up ok but the pressure only builds to about 20psi, also the cylinder heads get very hot very quickly. there are no obvious air leaks although there does seem to be quite a lot of air coming out of the control box that the on/off switch. Any help or advice would be greatly appreciated.
- Thread starter donaldmac
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malcolm
& Clementine the Cat
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I think mine is an airmaster tiger (though it could be something completely different). Same vintage.
I had a lot of trouble with the little plastic pipes blowing off their connections under that switch box. Could be a similar thing. Mine have now been botched on with tape and little blocks of wood.
Think the only other obvious place where air could actually be released is the pressure relief valve on the side of the tank in the same area.
I had a lot of trouble with the little plastic pipes blowing off their connections under that switch box. Could be a similar thing. Mine have now been botched on with tape and little blocks of wood.
Think the only other obvious place where air could actually be released is the pressure relief valve on the side of the tank in the same area.
rtbcomp
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The valve is in the base of the switch, its purpose is to dump the air between the pump and the non-return valve on the receiver to atmosphere when the unit switches off so the motor doesn't have to start under load.
It is designed not to close until the pressure builds up to about 20 psi. So the fault could be
1) As malcolm says, the thin plastic pipe has come off. (It's a push fit into the valve)
2) As Scot says, the valve is stuck
3) The non-return valve on the receiver is leaking
4) Flap valve(s) in the cylinder head leaking
5) Air leaking out of the receiver
Does it switch on and off OK with the red switch on the control box?
It is designed not to close until the pressure builds up to about 20 psi. So the fault could be
1) As malcolm says, the thin plastic pipe has come off. (It's a push fit into the valve)
2) As Scot says, the valve is stuck
3) The non-return valve on the receiver is leaking
4) Flap valve(s) in the cylinder head leaking
5) Air leaking out of the receiver
Does it switch on and off OK with the red switch on the control box?
peterd51
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Hi,
if it's been stored for any time and wasn't drained off then there could have been moisture in the system that's corroded internal parts, anything that's been mentioed so far.
Also, I had a problem with mine a couple of weeks ago where it was the flow meter leaking internally. In my case it got progressively worse until the motor couldn't shut off as it never reached the top pressure.
The cure was to remove the flow meter.
Mine's a Schneider but they all seem pretty much the same design from what I've seen recently.
Regards
Peter
if it's been stored for any time and wasn't drained off then there could have been moisture in the system that's corroded internal parts, anything that's been mentioed so far.
Also, I had a problem with mine a couple of weeks ago where it was the flow meter leaking internally. In my case it got progressively worse until the motor couldn't shut off as it never reached the top pressure.
The cure was to remove the flow meter.
Mine's a Schneider but they all seem pretty much the same design from what I've seen recently.
Regards
Peter
Thanks for all the great advice
Yes the compressor does start and stop ok with the switch on the control box although the box has now come loose so pushing the switch down just makes the box lift up.
It is quite possible that corrosion is the problem as the outside of the tank is fairly rusty, also the drain valve underneath has been replaced with a bolt at some point.
Yes the compressor does start and stop ok with the switch on the control box although the box has now come loose so pushing the switch down just makes the box lift up.
It is quite possible that corrosion is the problem as the outside of the tank is fairly rusty, also the drain valve underneath has been replaced with a bolt at some point.
rtbcomp
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Ah Ah - the dump valve is operated by a plunger on the switch mechanism, so if the switch moves the plunger may not operate the valve.
Try holding the box down with compressor running. Give it a minute or so to build up pressure.
rtbcomp
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When you say the box is loose, is it just the cover or the whole thing?
rtbcomp
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If it's just the cover that shouldn't cause the problem. Sounds like the dump valve has stuck open.
You could try disconnecting the thin plastic pipe and blocking the end so air doesn't escape and see if the pressure rises above 20 psi
If so the pump and receiver are OK and it must the dump valve leaking.
You could try disconnecting the thin plastic pipe and blocking the end so air doesn't escape and see if the pressure rises above 20 psi
If so the pump and receiver are OK and it must the dump valve leaking.
rtbcomp
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.........dont leave the pipe clamped or the compressor will cease to exist!!
No danger. The thin pipe is used to empty the air between the pump and the non-return valve. The actual pressure switch is operated by the pressure transmitted up the metal pipe that the switch is mounted on. The released air is what produces the hiss when the motor stops.
However you must release the pipe if the motor stops before you restart it otherwise it will be starting under load and will probably not start.
No the air leaking from the black box stopped when i clamped the pipe but the pressure still didn't rise above 20 psi. I had also wondered if some of the gaskets could have blown with standing for so long so i checked them all and used a bit of instant gasket, there doesn't seem to be any problems there.
Donaldmac
Donaldmac
rtbcomp
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I know it sounds daft - but is the gauge on the tank or the outlet side of the regulator?
I had a similar fault on a compressor and it turned out to be the valves in the cyclinder head, they were heavily coked up. I dismantled and cleaned them. The gasket was a couple of copper rings (IIRC) - I made new ones from some copper cut from the side of an old hot water cyclinder, suitably annealed.
I had a similar fault on a compressor and it turned out to be the valves in the cyclinder head, they were heavily coked up. I dismantled and cleaned them. The gasket was a couple of copper rings (IIRC) - I made new ones from some copper cut from the side of an old hot water cyclinder, suitably annealed.
