Greetings All,

I have been drinking deeply from the wealth of knowledge on this site for years. I decided to join because I need a bit of help with a machine and this site seems to be a bit more tech savvy than others. So here's the deal...

My new to me but used (2004 manufacture date) Expobar Office Lever is leaking via the OPV...more specifically, its leaking--not from any of the connection points--but from the (plastic?) set screw that allows you to increase or decrease the brew pressure. I do not have a pf pressure gauge...so I can't tell you how the brew pressure is running now...I also cannot say whether or not turning the set screw still adjusts the pressure up or down.

Apparently...the machine displaces water via the OPV in (two?) different ways...because there is a return hose going back to the water tank, but there is also another hose leading to a spout on that vents out the front of the machine and into the drip tray. When the machine is on, this spout on the front of the machine also constantly drips water into the drip tray...to the point that is is just shy of a steady flow and could easily fill the drip tray in several hours.

Another issue I've found with the machine is that it doesn't have quite as much steam power as I expected. I also own a Rancilio Silvia that is 3 yrs. old and it seems to have more steam power than the Expobar. The boiler pressure is set at 1 bar according to the pressure gauge on the machine.

Obviously, I have opened the machine...but other than the issues above, the inside of the machine appears to be relatively clean and in good order--aside from some rust on the frame caused by the leaky OPV I assume. That being said, the previous owner mentioned that he never descaled the machine because he used an RO filtration system and figured it wasn't necessary.

I'm planning to descale the machine, but was going to wait I get the leak fixed. However, I'm also wondering if a serious descale session might solve...or at least slow...the leak problem.

Should I go ahead and descale and see if that has any affect on the leak or steam power? Could the leaky OPV be removed, cleaned, and/or repaired? Should I just go ahead and replace the OPV?

Any help or insight you could offer would be greatly appreciated. Thanks to all.

Jason

Thanks for the info...very helpful...

Where could I get one with a brass plunger in the US?

Bella Barista has one of the heavy duty OPV's, but it's listed for use with the Brewtus and is a special order item.

Any thoughts regarding the steaming power? Shouldn't this machine have quite a bit more power than the Silvia?

Thanks again!

Ok...so in order to get the Expobar up and running...is there any reason why I couldn't/shouldn't use the opv from my Silvia on the Expobar?

I understand I might have to work around different fittings but it looks like both machines use the same pump...i.e. the Ulka E5 vibe pump.

This would just be temporary solution...until I could order and install a new opv.

If you unscrew the white plastic adjusting screw, you will see an o-ring designed to prevent just the leak you have. I BELIEVE the correct size is AS-11 available at any good hardware store.



The old o-ring, assuming it is very tired, can be removed by squeezing it and using a toothpick. Apply a matchheads worth of plumber's grease to the new o-ring after installation.

I BELIEVE the correct size is AS-11 available at any good hardware store.

Wow...I am beyond amazed you know that.

Dan referenced an article earlier that goes into great detail explaining how this earlier version of the Expobar opv is basically useless as a means of controling brew pressure. I believe it said that you couldn't get the pressure below 10 or 11 bars with one of these...which is why I was asking about replacement instead of repair.

I'm just making an assumption...but it would seem that the springs in my opv have also likely reached the end of their usefulness. I understand that replacing the gasket on the set screw would stop it from leaking out the top...but I don't see how replacing that gasket would stop the constant dripping from the vent spout on the front of the machine. Is that not an issue with the springs and/or balls not completely sealing off the valve chambers?

Don't get me wrong...I would much rather spend $2 on a few springs and a gasket than $50 on a new opv. However, I would rather not waste my time combing the shelves at the hardware store if the thing still won't get me down to 9 bars after it's restored back to "like new" condition. To be sure, I want to stop the leaks...but I also want to end up with a valve that is functional for managing brew pressure.

So repair or replace...your thoughts.

I'm pretty sure I could find suitable replacements for the set screw gasket and spring in a local hardware store. But I'm not so sure about the other spring that's in the horizontal section of the T...it's quite small and delicate.

. . . would stop the constant dripping from the vent spout on the front of the machine. Is that not an issue with the springs and/or balls not completely sealing off the valve chambers?

Time to undress Mr. Expobar and take pics. The vent spout on the front of the machine has to be fed from some source and its time to find that source. On OTHER machines, it originates from a "catch-can" surrounding the boiler safety valve. On your machine - ?

It takes a tremendous effort to write the article on OPV's that Dave C. wrote and that Dan referenced. But, it does contain some misleading statements. What is important to know is that the OPV is a relief/regulating valve installed to limit the MAXIMUM pressure seen by the system whether you're brewing, backflushing or whatever. The fluid-o-tech OPV works just fine as is whether it is installed in a system containing an Ulka pump or a Fluid-O-Tech pump. It was the standard OPV in the original Brewtus.

The "relief" flow from an OPV is TYPICALLY led back to the reservoir along with the discharge from a pump priming valve. This pump priming valve originated with Expobar machines ABOUT 7-8 years ago when they experienced problems taking suction from the reservoir - take that one with a grain of salt - memory from old alt.coffee days and posts.

Where are you in Virginia?

I've never seen this on any machine before...and yes it is counter intuitive...BUT, on this machine, the opv vents out the vent spout on the front of the machine. NOT back into the water reservoir. However, there is another discharge tube that connects between the pump and the OPV...and THAT tube discharges into the water reservoir.

See the pic below.

Abingdon, VA