[Patrick L.]

Any progress yet ?

I was thinking these were center-plain, they're not.

So, check that shoes are installed correctly. These have primary and secondary shoes. Primaries are short, secondaries long. Primaries go toward the front, secondaries rear. I've always been surprised at many times they are installed incorrectly, happens a lot.

As mentioned, check shoes for contamination. It that happened replace them. Why were they contaminated in the first place ?

Make sure they are adjusted correctly.

If all this is correct, a flex hose could still be collapsing. Doesn't happen often, but, it does.