Compressor troubles

[donaldmac]

There are actually two gauges, one is on the regulator and the other is on the black box with the on/off switch on it. I'll try stripping the whole unit and checking the valves ect. If that doesn't work i'll try filling the tank with petrol, setting light to it and rolling it off a cliff.

Donaldmac

 

[lexi]

My compressor burn out a month ago. I`m told it could have been a faulty gauge which was making the unit work too hard. I had just put a new Rexroth one on it plus a percolator...I wonder....

Alex

 

[wafe493]

Airmaster Tiger 8/40 turbo

I've got a similar problem on my Tiger 8/40. Pumps up to 40psi then pressure does not go any higher. No apparent air leaks anywhere, gauges on the regulator and pressure switch both read the same.
Never switches itself off as the pressure never gets up high enough. Have tried switching on/off with red button on pressure switch, no change, air filter is OK too.
It's only about 4 years old and has had light occasional use only.

Any ideas please ?

John

 

[rtbcomp]

Sounds like a sticking valve or worn piston. Is it oil-less? in which case it could be a perforated diaphram. When you switch it off does the pressure remain constant in the receiver, or does it lose pressure?

 

[wafe493]

Thanks for your reply RTB
I'm no compressor expert, but it does have oil & a dipstick so assume it's not oil-less.
The pressure stays up after switch off no problems.
I'd hope it's not a worn piston, the thing's hardly had any use since new, even though it's 4 years old & there's been no gradual deterioration, it's just suddenly stopped pumping up to 100 PSI.
What valve should I be checking ?

John

 

[rtbcomp]

I'd be inclined to suspect a sticking valve in the cylinder head. If the fault suddenly came on a valve could have broken or got partially jammed by a bit of muck.

Run it with the dipstick removed and see if air is leaking from the crankcase. You may feel a slight suck & blow, but if stream of air comes out that would suggest a worn piston or broken piston rings.

 

[gou077]

Air Master 8/40 compressor fault

I too have a identical fault pumps up to 40 psi only I have had the cylinder head off and cleaned the leaf valves to no effect a 1 year old machine

 

[RobWales]

Pressure Problem

I have the same fault, pressure builds up to 40psi, unit keeps running and doesnt switch off, Have stripped the whole compressor and can find no reason for this to be happening.

Unit is 5 years old, but very little use, and is stored in clean dry invironment.

Does anyone have any theories ??

 

[stormin]

Have you tried torqueing down the cylinder head bolts on the compressor?
Mine seemed quite loose after a couple of months use. Assume it was a bit of stretch in the bolts. I nipped them up and no problems since.

Only other problem I had was the manual drain valve not reseating properly once. Presumably a small piece of dirt from inside the tank had got lodged.

 

[RobWales]

head bolts tightened down, no torque wrench tho, head seals not leaking, poured soapy water over the seals to see if there were any leaks.
Tank holds pressure over night, so no leaks that side.

Am about to e-mail machine mart for advise, will let you all now if they solve the problem.

ThanX for the reply.

 

[RobWales]

Have had e-mail back from Machine Mart, this is what they said...."it seems like there may be a top end problem under the cylinder head.

There is a simple test you can carry out, remove the air filter then start the compressor let it build up to the 40psi keep it running and at the same time place the palm of your hand over the air filter port there should be a vacuum felt however if blowing then there will be a problem with the cylinder head gasket or/and valve strips and will need replacing."

I tried this and it seems to be blowing and sucking, so, I will try a new gasket....

 

[ianl007]

Probably no piont posting now but the problem is the rubber head gasket will have split dividing the inlet and outlet holes. It is a comman fault with these types of compresser and you will prob feel air coming back out the filter. The gaskets are a few quid to buy and easy to replace. Just incase anybody has any probs in future

 

[Exuptoy]

Probably no piont posting now but the problem is the rubber head gasket will have split dividing the inlet and outlet holes. It is a comman fault with these types of compresser and you will prob feel air coming back out the filter. The gaskets are a few quid to buy and easy to replace. Just incase anybody has any probs in future

Not necessarily, I bought a used Clarke se16c150 which would not build pressure. Lift off the head and there are 2 reed valves in there in some sort of head gasket plate. Mine were tired and cost me £38 (about 8 years ago or so now) and she's still running well.

 

[normspanners]

Not necessarily, I bought a used Clarke se16c150 which would not build pressure. Lift off the head and there are 2 reed valves in there in some sort of head gasket plate. Mine were tired and cost me £38 (about 8 years ago or so now) and she's still running well.

I have done several of these the standard gaskets either side of the valve plate are not up to the pump being used a lot. The gasket goes then it runs and runs till the pistons seize!!
I made the bottom gasket one out of copper and the top one out of ally but extended the bridge pieces into the inlet side so that the cool air coming in keeps the gaskets cool
my idea of using ally for the top one was so that it expands and tightens the head as it gets hotter.
The last one I did is working in a garage flat out (overworked really) and is standing it well.
He originally replaced the pump twice with brand new and it lasted 2 weeks Clarke said send it back we will look at it, it will be a month or so ???

 

[ianl007]

I was only saying it is a common fault with the 8/40 inparticular as it is the second time it has happened to mine because the peice of gasket that goes is only 2 or 3mm wide and have been told from machine mart that it has been rectified in the updated model 8/44. I am not going in to detail about them but compressors are relitivley simple machines and head gaskets or piston rings are the first things to go under normal working conditions. I have had mine since 2005 and use it all the time.

 

[Kal]

This is quite an old thread now, but I'm hoping that some of you might still get alerts that it has been updated.

I also have the Tiger 8/40 and experience EXACTLY the same issue: it pumps up to circa 40psi and then keeps pumping, but the pressure doesn't get any higher. I have cleaned the valves and they seem ok. The head gasket looks ok too, but maybe it is not.

What is definitely happening is that there is 'blow-back' from the air filter inlet once the pressure rises to that top end of 40psi.

It ran up to pressure when I bought it (second hand), and the only thing I altered was adding some proper Compressor Oil to the sump, as it was pretty much dry when I bought the machine. It was in nearly new condition, but Machine Mart don't want to know about these old models. It felt like it didn't run to pressure once I had added the compressor oil, but maybe that's just a coincidence. Dunno!

So it seems that quite a few of us have experienced this same problem and I was wondering if there is a consensus of what is the specific cause of it? Only as a last resort do I want to dismantle the cylinder and inspect the piston rings.

I await your collective wisdom. Thanks.

 

[carbon]

If its blowing back out the inlet then it wont be piston rings, either a valve broken, damaged or stuck open, or a gasket is damaged. I'm not familiar with that machine but the gasket above the valves should have a central divider to stop air going back to the inlet side of the pump

Also welcome

 

[Kal]

If its blowing back out the inlet then it wont be piston rings, either a valve broken, damaged or stuck open, or a gasket is damaged. I'm not familiar with that machine but the gasket above the valves should have a central divider to stop air going back to the inlet side of the pump

Also welcome

Thanks. I have checked the piston rings anyway and they look ok. So does the valves and the head gasket. Yes, there is the divider between inlet and outlet side on the gasket and everything looks intact (immaculate even).

I'm really at a loss with this machine. The fact that it builds up to 20+ psi no problem and during that phase it certainly 'sucks' at the air inlet. But then starts oscillating once up to about 20psi.

The one-way valve onto the tank looks so simple that I cannot imagine that failing. Anyway, that again works up to 20psi.

I'm fast losing my hair from all the head-scratching!