I have a bathroom faucet I cannot identify in the house I bought. The house was built in 1990. The cold valve works well. The hot valve works, but requires ~3/4 to 1 full revolution of the stem to start getting water flow. It actually shuts off again with very little rotation, but with no sensation of resistance, so everyone naturally continues to turn it another 3/4 revolution. I disassembled it, and the two stems are NOT the same. The faucet looks like the shower valve, and I have a brochure on the shower valve from Grohe. I have taken the stems to 2 large plumbing supply houses, and neither can identify it. I posted images and questions on the Grohe site, and the service agent said the valve is not Grohe. Can anyone identify it? The second picture shows the two stems. The upper stem is the hot water stem (the "mushy" one) and the lower stem is the cold one (that works well). I apologize for the differing size/aspect ratio. The differences are an extra rib above the middle O-ring on the hot stem, and no small upper O-ring on the cold stem. Any help would be appreciated.