Friends,

I have had the Rancilio Silvia v3 for 11 years. Recently, I accidentally ran the water pump dry for an hour. I ordered an EX5 water pump (with brass fitting) to replace it, and used the blue Loctite thread adhesive.

Unfortunately, there is still a leak in the metal flex pipe from the area circled in yellow in the picture. I thought this area was supposed to allow free-rotation of the nut when screwing in. There are no leaks from the thread areas on either part of the elbow joint, just the tiny space in between the end of the pipe and the nut.

Any ideas?

Thanks.

David
Indianapolis

I didn't put anything inside the nut, if that's where the crush washer goes. Maybe that's where it's leaking.

The area I was trying to indicate is above the nut in the picture, between the nut and the flexible hose. I just looked again, and nothing can go there.

A new hose sounds like a simple solution though. Thank you.

Thanks for the barricade idea. A good insurance policy.

So I ordered the replacement metal flex tubing with crush washers.

The upper end that screws into the 3-way valve at the boiler didn't have a crush washer originally. I used loctite, and that area does not leak.

Unfortunately, there is a different type of leak at the lower nut. I used one of the included crush washers and loctite. It sprays tiny jets out of several locations, again above the nut at the same spot as before, but instead of a drip, it's like when you put your finger over a garden hose. 3 tiny needle-size sprays.

I would say that it is actually worse than before I replaced the tubing.

Yea, I could ask for another hose I suppose.

Since I had the problem with the gap between the crimp and the nut on the first hose, this is what I did.

I installed the new hose at the top by the 3-way valve by spinning the hose, as the top nut did not rotate.

For the lower nut, I rotated the elbow while holding the nut with an adjustable wrench, so neither nut, nor the hose itself ever rotated.

Lastly I rotated the pump itself to screw onto the elbow. Strange, I know, but I never had to use a wrench on the crimp.

Basically yes. I may have had to move the nut but a little but I never put a wrench on the crimp. I had to put a wrench on the crimp with the original hose the first time when I replaced the pump, just to get the nut to back off the elbow and I thought I had damaged the crimp. Maybe that caused the first leak?

Maybe a third hose is a charm?

So they sent two compression washers with the new hose, which I could not find in the original metal hose when I removed it. It is a v3 Silvia but after 11 years of compression would they be worn away? There were no instructions so I wasn't sure where they were supposed to go.

I didn't put one in the brass pump fitting since it had some kind of spring and/or plastic parts inside the brass, which I thought might get crushed. The leak isn't coming from there anyway.

Honestly I would try a lot more frequently with different variations, it's just frustrating that the blue loctite has a "10-minute set" but a full 24-hr cure time.

If you hold it in bright light, you can see that the brass face that mates against the other surface is quite large and extends well up through most of the crimp... Hard to see in the picture and clouds kept drifting over when I was ready to shoot the picture, but it's a long piece of brass.

Assuming that the crimp didn't fail, the most likely path of that leak is between the mating surfaces, then up past the lip of the brass part and out at the loose area where it swivels, especially if you put anything on the threads (Don't put anything on the threads, just use a proper crush washer in there). The back of the brass and the nut aren't supposed to be a seal, they're just supposed to allow the swivelling until tight. Water shouldn't ever get there if the mating faces are sealed.