GregHammerstein
New member
I have a new M9040 4-wheel drive hydro-static transmission with less than 25 hours total time. The tractor produces an intermittent, but consistent "hissing" or "whistling" noise that is coming from the upper right-hand side of the engine compartment firewall. The noise comes and goes and seems to be related to and aggravated by increasing engine rpm slightly above idle. I've repeatedly been able to stop the noise by applying the brakes 3 to 4 times, either with both pedals together or either pedal separately. The noise goes away completely for about a minute but always returns. I can always clear the hissing noise by tapping the brakes several times. The noise definitely sounds like air hissing through a leaky hose. Curious if anyone has had similar experience or a recommendation before I go through the trouble of hauling this tractor back to the dealer. Thanks.