I have replaced my proportion valve with a brand new item. Now one of the bolts to the rear hard line is leaking where is connects to the prop valve. I replaced this valve because it was leaking. Now the line is leaking. Arrgh. The manual says it should only be torqued to around 15nm, which is really not very tight. Could it be possible that over tightening it has caused the leak? Help please, I hate brake leaks..