Compair H37 dumping oil when turning off

[bert]

We have a compair H37 road compressor that we use for sand blasting. When we turn it off the compressor dumps a load of oil into the air line and out of the pressure valve in the pic on top of the oil separator

Does anyone know what's wrong with it and what we need to do to fix it?

 

[mtt.tr]

Check that the scavenge line is clear and that the check valve is good

These are the brass fittings ontop of the reclaimer / SEP vessel

You say dump, how much oil are we talking?


And are we talking pressure relief valve? If so this is pre separator so could be going over pressure? Will it idle ok or does it over pressurise?

 

[bert]

The oil is coming out of the side of this as well as the main air outlet.

It let's about 0.2 liter each time it's turned off with a majority of that in the main air line

 

[brightspark]

it will probably be the oil filters clogged up in the large round drum if theres oil passing in the line and need replacing it isnt scavenging it out

 

[mtt.tr]

The oil is coming out of the side of this as well as the main air outlet.View attachment 350590

It let's about 0.2 liter each time it's turned off with a majority of that in the main air line

Either it's not scavenging properly or the separator has failed or the oil is foaming due to age which will cause it the pass through the separator.


When was it last serviced?


If it helps the working principle is this.

The screws push oil and air through to the big vessel.

Once it hits the vessel which is also an oil sump the oil drops from the air,

The air passes through the separator and any remaining vapour/mist clumps to the inside face of the separator element it then runs down the inner edge and collects in the base of it,

At the same time air exits through a minimum pressure and check valve to the outlet taps.

Now from the lid down to the separator base you have a tube, this is the scavenge line, this line is easy to identify as it goes to the low pressure side of the compressor which means it collects/vacuums oil from the separator base back in to the pump.

This is essentially the cycle of the oil.

So any passing oil means either Its not scavenging or the separator has failed


If you run the air do you get a constant stream of oil from the outlet?

 

[brightspark]

unbolt the lid of the filter cylinder and pull them out mine were a type of fibre about 6 of them on a tube and were choked so i washed them in petrol saved renewing them. bad news was the air stunk of petrol for a while and my breathing air was plugged in to it so had to supply it of my electric comp till the fumes disappeared

 

[mtt.tr]

unbolt the lid of the filter cylinder and pull them out mine were a type of fibre about 6 of them on a tube and were choked so i washed them in petrol saved renewing them. bad news was the air stunk of petrol for a while and my breathing air was plugged in to it so had to supply it of my electric comp till the fumes disappeared

They do get expensive, did about 6months with a main dealer compressors are the best kept secret.

Scarily simple but people completely over sell how complicated they,

 

[Brad93]

Check that the scavenge line is clear and that the check valve is good

These are the brass fittings ontop of the reclaimer / SEP vessel

You say dump, how much oil are we talking?


And are we talking pressure relief valve? If so this is pre separator so could be going over pressure? Will it idle ok or does it over pressurise?

How much do you know about these Matt?

Ours needs attention. Have a manual.

 

[mtt.tr]

How much do you know about these Matt?

Ours needs attention. Have a manual.

I very quickly became the person to send to breakdowns if they wanted it repaired or atleast diagnosed first time round

 

[bert]

Either it's not scavenging properly or the separator has failed or the oil is foaming due to age which will cause it the pass through the separator.


When was it last serviced?


If it helps the working principle is this.

The screws push oil and air through to the big vessel.

Once it hits the vessel which is also an oil sump the oil drops from the air,

The air passes through the separator and any remaining vapour/mist clumps to the inside face of the separator element it then runs down the inner edge and collects in the base of it,

At the same time air exits through a minimum pressure and check valve to the outlet taps.

Now from the lid down to the separator base you have a tube, this is the scavenge line, this line is easy to identify as it goes to the low pressure side of the compressor which means it collects/vacuums oil from the separator base back in to the pump.

This is essentially the cycle of the oil.

So any passing oil means either Its not scavenging or the separator has failed


If you run the air do you get a constant stream of oil from the outlet?

Thank you, we will pull it apart on Monday for a look.

No oil when running only when you shut it down and it pukes for a second or two.

No idea when it was last serviced as we have only just got it.

 

[brightspark]

Thank you, we will pull it apart on Monday for a look.

No oil when running only when you shut it down and it pukes for a second or two.

No idea when it was last serviced as we have only just got it.

when my filters were blocked there was a verry fine blue tinge of oil in the air at full belt with an open hose

 

[mtt.tr]

Any updates?

 

[bert]

Not yet as we have not had a chance to take a proper look. We are opening the 2nd air line before shutting it down and that's stopping it puking out the oil.

 

[mtt.tr]

Not yet as we have not had a chance to take a proper look. We are opening the 2nd air line before shutting it down and that's stopping it puking out the oil.

How are you shutting it down? You need to reduce the engine speed and let it idle for a moment