Expobar pump problem after 5 day trip

[jjue]

Hello,

I recently went on a 5 day trip to seattle (to taste coffee of course!) and when I came back I realized my expobar pulser was left on the whole time. I think all the water in the boiler dried up because when I activated the pump it was churning dry (this can't be good for it). It eventually sucked up water and was working fine.

A couple days later, I noticed that now my machine puts out far less water out of the grouphead when I activate it. It's about half as before. When I put a blind filter in the grouphead and hit brew, it takes it about 10 secs to change sound of the pump when I backflush it. Before, it took about 5 secs to do that. The changing of sound I assume is the pressure building up in the grouphead to a point where no water can be added.

When brewing an espresso, it takes about 12-15 secs for the espresso to come out (blind portafilter).

What can be wrong? Did I fry a gasket inside? Can I fix this myself? Thanks!

Jason

[HB]

I've read a couple reports of Expobar pumps "losing prime" / developing a vacuum after being idle for a day or two. Searching "prime pump" in the Brewtus forum for example:

Now then- I think I have a problem with my Brewtus. During a series of blind backflushes yesterday I noticed the pressure and volume of water coming from the bypass valve spout to be decreasing with each flush
(5-6 flushes in total). By the last flush there was significantly less water coming out of the spout and with much less force than on the
first flush.

cont'd

I have had my BII for almost 4 months now with no problems until this morning. I started it up and let it sit for 3 or 4 hours before I got around to pulling a shot. I pulled the shot and now the pump sounds like it wants to pump, but doesn't stop running. I check the two water lines in the tank and there is no water in them, just air bubbles. They just pump air into the water tank.

cont'd

When I couldn"t get my pump to prime, with the water softener removed, try filling an 8oz. squirt bottle with water(the kind that could be used for mustard or ketchup), hold it high and upside down and connect your input hose to the tapered tip. Turn on the pump then squeeze your bottle. It holds enough water to get everything going again. This is something I made up, but it seemed to work good for me.

link

Abe reported the same problem on his Brewtus. I recall reading similar reports of "losing prime" with other Expobars, including I believe the Pulser. That's where I would start. If this doesn't help, then my next step would be to start from the inlet hose (check for obstructions), the pump (check flow rate), over pressure valve (check it's not venting too much), etc.

[jjue]

Great, thanks. I will look into this. Is it bad to leave the Expobar Pulser on for 5 days straight? Would that damage any parts or are there some people that leave their machine on for extended periods of time like that? Thanks.

Jason

[HB]

Sure, some never turn off their espresso machines as long as they're auto-fill. See Leave it on, turn it off? for the advantages and disadvantages.

[stevey2k]

Did you get this diagnosed or fixed? I have the exact same problem, and I'm still struggling with trying to fix it.

Thanks!

[jjue]

No, actually I haven't gotten it resolved. I called wholelattelove tech support and the guy there suggested that I clean the grouphead and backflush with backflush detergent. I did the backflush thing but it didn't help. I couldn't figure out how to remove the screen on my grouphead. I honestly don't think the screen/group is clogged or excessively dirty because i backflush and clean all the time right after I make a shot.

The tech guy really didn't know what it could be because it worked normal for a few days and then reduced water output. I will let you know here if I figure out what is wrong. Likewise, please let me know what you find.

I haven't had a chance to look into all the possible solutions mentioned on this thread.

Stevey2k, what led your machine to have this problem? Did you leave yours on for a long time too?

- jason

[stevey2k]

I also tried backflushing, it seemed to help somewhat, and then possibly slowed down again shortly afterwards. I asked the same question on coffeegeek not long ago, and it was suggested to me that I backflush a lot, as in around 10 full cycles or so. I haven't done it to that extent (yet).

I also wanted to remove the grouphead screen to clean the grouphead more thoroughly, and also can't get it off. I was told to use a flathead screwdriver to pry it loose on each side, and that it's a real bear to get out. I can't get the blade of the flathead between the screen and the grouphead, so I've no luck in that area.

The problem occurred for me when I backflushed during what I believe was vapor lock with the machine. After shutting the machine off and several cycles of fidgeting, the machine eventually righted itself to the current condition.

My guess is some kind of clog or a faulty pump. It it is the pump, I'd prefer that it just fail entirely so I can at least get the machine fixed.

If I have any luck, or try other fixes, I'll post here.

[jjue]

Also, I forgot to mention that my steam output seems normal... Just the amount of water coming out of the grouphead is reduced. That is why the guy at WLL thinks my group is dirty. Is that the same for you Stevey?

Regards,

Jason

[stevey2k]

That's exactly the same for me - steam wand and water wand are fine. I'd like to get the screen off the group head and find out exactly what's going on in there.

[HB]

The steam and water wand are fed from boiler pressure, not the pump. As I suggested earlier, if the water flow is anemic, I would start from the pump and move towards the grouphead. But if you want to peek behind the dispersion screen, see How to remove the dispersion screen and gasket of an E61 and Jeremy's related post:

I use a flat head screwdriver to leverage the basket. admittedly, this is easier with a groovy screen. i do this with my ungroovy ones too, but, same as Dan, I tend to scratch the outside of the housing on the ungroovy. I have also destroyed an ungroovy screen by trying to use the "spot welding ring" as a groove.



If you use the grouphead as the fulcrum, and get enough friction between the screwdriver and the outside of the screen housing, both the screen and the gasket will "pop" out together.

[jjue]

Dan thanks for the additional information.

Here are some pictures and video of the insides and workings of the machine. Hopefully people can find something that can give a clue as to what is wrong.

http://www.jasonjue.com/temp/expobar/

Well, tonight I opened my Pulser up to look for anything wrong. I first removed the brew screen and gasket. It was much easier to do this when the machine was laying sideways. They both came off with minimal effort, though the gasket had some of the edges rip off when I took it off. After that, I soaked the screen in detergent and cleaned the gasket. The screen was fairly shiny clean to begin with.

I put the gasket and screen back into the brew head and stuck in a blind portafilter. The gasket was leaking. So, I took the screen and gasket off again, removed the loose edges to the gasket, re-inserted it, and it didn't leak.

Next I wanted to try to re-prime the machine. I heated the machine up, removed the water tank, and emptied all the water in the boiler with the steam wand and hot water dispenser. I then cooled the machine down (about 40 min), put the water tank back, and started up the machine (see video). Everything seemed normal; it immediately began sucking up water to the boiler.

I let it heat up a little more and tried to pull some blind shots but noticed the water coming out was even less than before. Lots of bubbling from the brewhead. I think the boiler didn't quite fill up and it just need more time to prime to get out all the air. After a couple shot pulls things seemed to get better. There seemed to be less bubbles and more water started to flow out. In the end though, it seemed like the amount of water coming out of the brew head is the same as before (about half as much from when I first got the machine).

I have some pics and video you can see...I don't know what to look for, so, hopefuly someone will spot or hear something unusual.

Is the flow that now is coming out of the brewhead normal?

What should I do next? Also, I can reshoot stuff if you want to see something at a better angle.

Regards,

Jason

[HB]

Hopefully people can find something that can give a clue as to what is wrong... What should I do next?

This extraction looks pretty good, what's the problem?

http://www.jasonjue.com/temp/expo...urce/shotpull.html

The unimpeded water from the grouphead might be a tad slow, but I wouldn't be concerned if the actual brew pressure and extraction volume is reasonable. While you have everything apart, you could check the gicleur valve and screen are clear. See E61 Group Espresso Machine: Detailed Interior Schematics:

Here's the close up of the brew path.

The water entry should be obvious, then it travels up, thru the bright green section, thru the filter screen (transparent grey), down thru the gicleur (yellow), into the valve section (blue). The valve is shown closed.

When the orange cam rotates up (it's attached to the lever), it pushes up the valve seal (yellow) and brew water floods the cam area, then goes up towards the infamous allen screw. (Now it should be apparent why it's there as well. It would be hard to drill around that corner.)
Then down toward the dispersion disk.

The gray cylinder above the yellow gicleur is the screen I'm referring to. It's remotely possible that one of the two are slightly clogged, but again, the extraction video above looked reasonable to me.

[jjue]

Sorry for the late response, I've been busy at work.

Well, the reason why I think there is something wrong with my machine is that the characteristics of the machine have changed so much over the course of a couple days. I've had my machine for about 3 years. For the past year I've been using the same grind settings (+or- a half step on my moka grinder), and the timings have always generally been the same.

Recently, I noticed a significant reduction of water coming out of the brewhead.

Approximately...

Before:
grinder setting of 3 or 3.5
backflushing: with blind filter, takes 5 sec to build up pressure (change in sound of pump)
shot timing: 8-10 sec for first coffee to come out (naked PF), 25 sec shot at 1.25 ounces.

Now:
grinder setting of 3.5 or 4 (I now have to use the setting that I used to use for a lungo shot for a ristretto)
backflushing: takes at least 10 sec to build up pressure
shot timing: last I timed it, it took 18 secs for first coffee to appear, 25 to 30 sec shot time for 1.25 ounce.

Overall, there is less water coming out of the brewhead. By setting the grinder to one click coarser, I can still get a 1.25 ounce shot within 30 secs. So, the machine is still usable, but, why was there a sudden drop in water output?

Thanks!

Jason

[HB]

So, the machine is still usable, but, why was there a sudden drop in water output?

I listed a number of possible causes earlier. Given the sudden change in behavior, another possibility is a sticking / clogged grouphead solenoid. Have you descaled your machine lately (especially the HX / brew pathway)?

[jjue]

The espresso gods have blessed me.

After removing the screen, cleaning, backflushing, etc...nothing seemed to work. I lived with it, but my flowrate was slowing reducing to a point where it would take 20 secs for water to flow out of the PF! It was getting worse. I needed to do something.

Today I decided to check out the group head area. So, I opened up the group head, and cleaned the area of the screen and gicleur. I would say there was moderate calcium buildup; nothing that I could initially see blocking anything. It took me a while to figure out where the water flows after it goes thru the screen. The gicleur just looked like a sealed nut. Huh?

I eventually realized that there's supposed to be a hole at the top of the gicleur. It was completely clogged (corrosion/calcium). I cleared it with an x-acto knife and my machine runs like new!

I'm guessing this happened after I left my machine on and it all dried up, crusting up at the gicleur hole. I think things got a little corroded around that area cause it dried up; beforehand there would always be water in there.

Thanks Dan and everyone else for the suggestions. This was all my first time opening up the machine and I learned a lot about how an espresso machine works.

Regards,

Jason

[stevey2k]

I'm having the same problem as Jason, and I'm having difficulty locating my gicleur. I opened the top of my machine, removed a large nut on top of the grouphead, and what I see is a vertical piece made out of white plastic. I don't see a grey screen as expected.

I think I'm really missing the boat here. Am I looking in the right place? Unfortunately, the fancy schematics drawings that are posted aren't helping me.

I also have an Expobar Office Pulser.

[jjue]

Stevey,

The schematics actually didn't help me that much. When I took apart my machine, I tried to think how the water flowed through the different pieces I took apart. In my case, I discovered the clogged hole in the gicleur because there was no other place for the water to flow.

In other words, don't rely too much on finding the right part in the schematics. I would try to see if there are any restrictions in the water flow in your brewgroup. Basically, water flows into the grouphead, up towards the top, forced thru some filter/screen thing, and pushed down. I don't know what happens after that. You can probably find more about it online.

We may have different groupheads. I bought my expobar in 2003.

Hope this helps! Good luck.

jason

[stevey2k]

Hmmm...it seems as if Jason and I have different groupheads(?). I could use some guidance in finding the gicleur so I can check to make sure it's not clogged.

Can anyone suggest how I can find it? As I mentioned in a previous post, removing the large nut at the top of the grouphead only revealed a vertical plastic piece, which didn't seem removable.

I contacted the vendor, and received a reply that they didn't know what a gicleur was.

Guidance greatly appreciated!

[jjue]

Stevey,

Do you have pictures you can post so we can see?

Jason

[stevey2k]

That's a really good idea! I'll take and post some pics this weekend.

Thanks!