(I've already posted this question to the "Red" forum but I'm trying here as well to see if anyone here has any ideas... Note that this is the same setup as on a 574, 674, etc. Thanks!)
I had the lift cover off my 454 to replace the parking brake band, and while I had everything drained I also replaced the filter and cleaned the screen. After reassembly everything works fine: lift, PTO, steering, brakes (after bleeding) but now the lube pressure light is on nearly all the time. Previously it would only flicker on occasionally. This is one of the early ones with the switch going into a rectangular lube regulator valve block rather than just a tee.
I checked the PTO linkage using the procedure in the manual since I know if it's misadjusted it can cut off the oil cooler circuit, but that was okay. I also just-to-make-sure put a few more gallons of fluid in, and the system is now full significantly over the mark on the dipstick.
Then I took out the switch and put a pressure gauge on the sender hole. When cold the reading bounces all over the place but when it's warmed up I see a consistent 5psi with the PTO on and a consistent 4psi with it off. I don't have a flow-rater so I can't do the test in the manual to measure how much oil is actually coming out of the lube pump. I don't feel good about running the machine with that little pressure in the lube circuit.
So at this point I see several possibilities: 1) the lube pump is bad or its drive gear is messed up or something (which seems unlikely as it was apparently okay before, and I didn't do anything to it), 2) the O-ring under the lift cover got shifted and there's a leak between the lube pump and the lube regulator (it would have to be an internal leak, as there's no oil coming outside past the gasket), 3) there's a little piece of old gasket or other crud blocking the passage through the lift cover, 4) the lube regulator has gone bad or has a piece of crud in it.
But I don't know how to figure out which of these it is except by tearing everything apart again, and I don't want to take the fuel tank and platform and lift cover off again unless I absolutely have to. Any suggestions on things to try first (for example, is there any way to fiddle with the regulator), or possibilities I've overlooked? Thanks again.
I had the lift cover off my 454 to replace the parking brake band, and while I had everything drained I also replaced the filter and cleaned the screen. After reassembly everything works fine: lift, PTO, steering, brakes (after bleeding) but now the lube pressure light is on nearly all the time. Previously it would only flicker on occasionally. This is one of the early ones with the switch going into a rectangular lube regulator valve block rather than just a tee.
I checked the PTO linkage using the procedure in the manual since I know if it's misadjusted it can cut off the oil cooler circuit, but that was okay. I also just-to-make-sure put a few more gallons of fluid in, and the system is now full significantly over the mark on the dipstick.
Then I took out the switch and put a pressure gauge on the sender hole. When cold the reading bounces all over the place but when it's warmed up I see a consistent 5psi with the PTO on and a consistent 4psi with it off. I don't have a flow-rater so I can't do the test in the manual to measure how much oil is actually coming out of the lube pump. I don't feel good about running the machine with that little pressure in the lube circuit.
So at this point I see several possibilities: 1) the lube pump is bad or its drive gear is messed up or something (which seems unlikely as it was apparently okay before, and I didn't do anything to it), 2) the O-ring under the lift cover got shifted and there's a leak between the lube pump and the lube regulator (it would have to be an internal leak, as there's no oil coming outside past the gasket), 3) there's a little piece of old gasket or other crud blocking the passage through the lift cover, 4) the lube regulator has gone bad or has a piece of crud in it.
But I don't know how to figure out which of these it is except by tearing everything apart again, and I don't want to take the fuel tank and platform and lift cover off again unless I absolutely have to. Any suggestions on things to try first (for example, is there any way to fiddle with the regulator), or possibilities I've overlooked? Thanks again.
