On expobar brewtus IV with a blind portafilter in, and allowing the pressure to build to 9 bar, the 3 way valve will release a little pressure yet there is still a significant sneeze when the portafilter is removed. The water coming out of the 3 way appears clear. Outside of this method I cannot get the 3way valve to release anything. The machine has always had soft water through it and has been backflushed/cleaned regularly.

Could the bottom bolt on the E61 be too tight, preventing proper release of pressure or....? Any ideas?

If your E61 has a lever, it releases pressure differently than a 3-way solenoid valve (i.e., like on a Rancilio Silvia, Gaggia Classic, etc.). See Is there a purpose for the E61 middle brew lever position? for details, specifically:

HB wrote:Please do not copy these images.

The first image shows the E61 lever at the rest position. The two lower valves are open to allow the brew chamber and expansion chamber to drain. The uppermost valve is closed. Water from the HX circulates through the upper port on the left, passes alongside the "mushroom" to heat the grouphead; as the water cools it descends through the lower port on the left. The temperature difference creates a thermosyphon that circulates water between the boiler and grouphead.

Is this an older espresso machine? It's possible the pin on the exhaust valve has worn down enough such that it no longer pushes the upper exhaust valve open. See Randy's HOW-TO 19: Overhauling and Lubricating the E-61 Group for step-by-step instructions.

Thanks for the quick response Dan, I did see your posting in the other thread though with the valve releasing pressure when there is a greater buildup I was wondering if there was something else going on. The machine is a brewtus IV and is about 2 years old. I recently purchased it used and currently assessing its health. My method for pushing the lever all the way closed is the same with a blind portafilter as it is with a puck of coffee and even with the blind it doesnt always release. I'm wondering if this is a quick fix or something more. The person I purchased it from has been great I just wanted to see if I could assess whats going on with the machine, maybe its as simple as loosening a bolt. What are your thoughts?

I think it is likely due to a buildup of coffee oils/gunk inside the drain chamber of the group head. You can easily unscrew the bottom parts of the group head using a wrench. Start with the bottom most piece and work your way up. Just pay attention to how the parts are assembled (there will be a spring and valve in the drain chamber and the pre-infusion chamber). I bet the machine was either never backflushed with detergent or at least not regularly enough to prevent buildup and this buildup of gunk is clogging the drain.

I would then soak the parts in espresso machine detergent and clean them with a small brush prior to reassembling.

The best guide I have found on how to do this is http://www.espressomyespresso.com/HowToE61overhaul.html. You only need to do the steps in "Lower Group Parts" starting at step 6, but I would recommend that you do the "Upper Group Disassembly" (steps 1-5 ) to get an idea of scale buildup on the mushroom and the state of all of the e-61 valves.

The exhaust valve is either stuck, the lower pin that rides the brew cam is worn down, or as John suggests, it could be so gunked up it doesn't drain . The hope that there's a bolt you can turn to fix it is wishful thinking, but Randy's tutorial walks through the steps to confirm the cause one way or another.

For reference, Espressocare sells the E61 infusion valve that typically wears out and a handy Grouphead E61 Rebuild Kit.

Just be aware not all E61 groups use the same length lower pin. I've seen them from 11 to 14mm and you need the correct length for your machine's implementation. For instance my former Bricoletta used a 13mm but my VBM DD calls for a 14. Unfortunately I have no idea which one the Brewtus IV uses.

Could the bottom bolt on the E61 be too tight, preventing proper release of pressure or....? Any ideas?

Positively . . .No.

I believe your problem lies with a partially clogged dispersion screw in the grouphead.



Removing that dispersion screw can be a real PITA . . . but your turn to fabricate/purchase some great tools.

Use the paint can lid remover on the dispersion screen and the modified stainless fender washer on the dispersion screw.



For sure, anything in the exhaust passages (clogging up) could cause the problem you are experiencing and the disassembly/cleaning/inspection as per Randy G.'s procedures previously mentioned might be your best first step . . . certainly the easiest.

While I don't disagree with the trouble shooting suggestions, the described symptoms can most definitely be the exact cause of worn lower pin. I've seen it happen and cured it by replacing the worn lower pin more than once. The lower pin is very easy to access taking apart the lower tube, by visual inspection a worn pin is very apparent to see.