Posted Thu Sep 6, 2012, 2:41am Subject: Oscar leaking from expansion valve
hello everyone.
hoping someone can help me figure this out.
My oscar is leaking from the expansion valve that is connected to the grouphead.
When the machine is getting up to temperature, i can see and hear water coming out between the group and the valve.
I tightened down the valve as far as i can, to the point of stripping the copper so i'm pretty sure it's as far as it can go.
Also, this is a new expansion valve.
Am i missing something that would better seal the threads to the group?
What ends up happening is that it slowly leaks enough to cause water to accumulate on the bottom of the case and then eventually leaks out. Also wreaking rust havoc on the bottom of the metal frame.
NobbyR Senior Member Joined: 10 Jul 2011 Posts: 1,608 Location: Germany Expertise: I love coffee
Espresso: Poccino Opus One, Ariete Grinder: Eureka Mignon Istantaneo,... Vac Pot: N/A Drip: Melitta Linea Unica de Luxe Roaster: N/A
Posted Thu Sep 6, 2012, 4:08am Subject: Re: Oscar leaking from expansion valve
Basically it's normal that small amounts of water leak from the expansion valve (not the 3-way-valve!) during heating up or after shots. For how long have you had the Oscar? About how much water are we talking about? Is this behaviour new?
*** "This drink of the Satan is so delicious that it would be a shame to leave it to the infidels." (Pope Clement VIII on coffee)
calblacksmith Moderator Joined: 25 Nov 2007 Posts: 5,671 Location: Riverside, Ca, U.S.A. Expertise: I live coffee
Espresso: ECM Veneziano A1 Grinder: Many different commercial Vac Pot: 40s era Silex Drip: Milita, Bunn&Curtis... Roaster: Cast iron pan, gas burner
Posted Thu Sep 6, 2012, 6:01am Subject: Re: Oscar leaking from expansion valve
Just asking here, are you referring to a vacuum breaker valve? They normally leak until pressure builds up but the Oscar does not have one when it comes from the factory, if it has one it has been added by someone.
If that is not what you are talking about, nevermind.
That said, I had an Oscar for over a year and it NEVER had any sort of pressure or water leak on heat up, well until I added a vacuum breaker anyway, then it operated normally for a machine with a vacuum breaker. bleeding pressure until the boiler heated to the point of producing steajm which then closed the vacuum breaker and the machine heated normally and did not leak water or pressure from anyplace.
In real life, my name is Wayne P.
Feed the newbs, starve the trolls and above all enjoy what you drink!
Posted Thu Sep 6, 2012, 7:55am Subject: Re: Oscar leaking from expansion valve
i attached a pic of the stock expansion valve. It's leaking from the threads and down onto the hot water line and then down to case and then mostly into the drip tray. with the drip tray removed, i can build up a good sized puddle from just one shot.
i've had this oscar for about a month now but i bought it used. looks like it hadnt been taken care of well before it got to me. the expansion valve on it is brand new as i had an issue with the old one where it would clog and wouldnt release pressure. I think this started after i replaced the valve.
calblacksmith Moderator Joined: 25 Nov 2007 Posts: 5,671 Location: Riverside, Ca, U.S.A. Expertise: I live coffee
Espresso: ECM Veneziano A1 Grinder: Many different commercial Vac Pot: 40s era Silex Drip: Milita, Bunn&Curtis... Roaster: Cast iron pan, gas burner
Posted Thu Sep 6, 2012, 2:19pm Subject: Re: Oscar leaking from expansion valve
I'm sorry for my confusion, I forgot about that valve on the Oscar.
You say it is from the threads, I know I have had brass fittings fail when tightened too tight. I had one under my kitchen sink crack and it started dripping, not fast but steady, we didn't see that it was leaking for who knows how long until the water came out from under the hard wood floor on the opposite side of the kitchen, flooding the underlayment and all, a real mess just because the fitting was a LITTLE over tight and had a delayed crack after being overtightened.
Is it possible you over tightened and cracked either the fitting or the group head? On brass fittings (I learned the hard way) you need a good thread sealant and then only tighten enough to not leak, that extra 1/8 turn for luck..... sometimes isn't so lucky!
In real life, my name is Wayne P.
Feed the newbs, starve the trolls and above all enjoy what you drink!
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