Compressor help

[brnomauser]

I'm hoping someone might be able to help with a compressor I have been given. I said the small black hose came out from under the main switch. It doesn't start up unless the hose is open, then looses pressure fast if it's not blocked once it's running. But it doesn't hold main tank pressure.

But I can't find an obvious place for it to reconnect. It isn't the most fancy of compressors, but I see it costs almost 200 new so is worth fiddling with IMO. It's an ABAC OM231 direct drive.

This ebay has photos that show roughly where it goes - http://cgi.ebay.co.uk/Compressor-AB...Air_Tools_and_Compressors&hash=item3cb712fd85

detached hose

Can't see where it goes

 

[shenion]

Hard to see in the pics. Looks like the unloader valve is missing.

Probably easiest to get a new pressure switch. You may have to add some adapters/tees to use a standard one.

 

[FranV8]

I'll take a picture of mine under the pressure switch when I get a moment - but I've an identical machine. It's the sort of compressor you could buy new for around £100, perhaps less, but it will do a fair few tasks, as long as you don't mind waiting for it to catch up from time to time.

Anyway, as the hose that comes out is the one to the pressure switch, I guess it must work on some sort of differential pressure within the switch, hence it also won't start without it blocked off? Should be an easy-ish fix, but might need a new switch if it's a fitting that has broken off.

 

[pedrobedro]

It's the pressure bleed pipe. When the tank is up to pressure the switch releases the pressure in the feed pipe so the pump can start up easily not fighting the pressure in the tank. If the brass bit under the switch is a union it may be you need the other half of it to reconnect the pipe. Unloader valve.

 

[brnomauser]

Thanks a lot guys, if I could get by just fitting a new unloader valve that would be great then. I want one for an MDR1 though right? That link pedrobedro only lists for BDR 2 and up.

But I can get also a generic pressure switch then?

This link http://www.jbltools.co.uk/abac-pole-position-om231-24ltr-air-compressor-415-p.asp has them at £185 so it's worth my time I think. FranV8 if you could post a photo of yours that would be great.

 

[jordan1]

Thanks a lot guys, if I could get by just fitting a new unloader valve that would be great then. I want one for an MDR1 though right? That link pedrobedro only lists for BDR 2 and up.

But I can get also a generic pressure switch then?

This link http://www.jbltools.co.uk/abac-pole-position-om231-24ltr-air-compressor-415-p.asp has them at £185 so it's worth my time I think. FranV8 if you could post a photo of yours that would be great.

That one is a 2HP, yours is a 1.5HP which will probably make the difference.

 

[brnomauser]

That one is a 2HP, yours is a 1.5HP which will probably make the difference.

hmm, .5hp = 100 pounds? That's a bit steep. Even so I won't disagree, but I guess it's still worth a 10 pound pressure switch

 

[jordan1]

hmm, .5hp = 100 pounds? That's a bit steep. Even so I won't disagree, but I guess it's still worth a 10 pound pressure switch

Most certainly.