450C hydraulic pumps - differences between 6 way and manual blade

[kilohertz]

Well happy new year everyone! It's been a crazy busy year and I haven't played with the dozer in a year but I got it out yesterday to remove 2' of built up snow in the yard, just too much for the Bobcat. It got me thinking about all the things I need to do to my machine, I bought it in August 2018 and it's basically sat since.

It was born with a 6410 manual blade but has been changed to the 6405 6 way blade. What I noticed today (again) is that the movement of the blade is very slow, especially the angling L-R, but really just slow. I was running it at 1600 RPM, just into the green on the tach. I checked with the JD parts catalog and from what I could see there are 3 pumps 15, 19 and 23 GPM, and they list each pump for all 3 blades, which doesn't make sense to me. I would have thought the 23 would be used on the 6 way, but not the 15GPM. I'm guessing mine has the 15 but won't be able to tell until it warms up here and some snow melts.

Interested to hear your thoughts, and what pump, if you know, is on your 450 machine. I checked the catalog and the same 23GPM pump is used on the 350 loader, and as I have one sitting in the yard, could swap into the 450.

Look forward to some guidance please and thanks.

Cheers

[NWJD fan]

My understanding is 15 gpm pump is standard for dozers but 23 gpm is used if machine is running a back hoe attachment. My 450C with 6410 blade and 15 gpm pump is plenty fast. Also heard the 6 way blade is a little twitchy with 23 gpm pump

[Jim B]

Parts catalog shows the 15 gpm was used on 450Cs up to serial number 380045. Starting with 380046 the 19 gpm was used. Where does your serial number fall? The 23 gpm pump is not tied to any serial numbers. I suspect, as NWJD mentioned, the 23gpm was likely installed mainly on dozers equipped for/with a backhoe attachment.

The JD Technical manuals usually have the function cycle times in the hydraulic testing/diagnosis section, I know the manuals for the Bs and Es have them. Check your manual (TM1102) for the cycle time specs and time the cycle times of your machine. That comparison will give you a real basis to start from. The cycle times are checked at "high idle" (2500 rpm +/-). As for angling speed, I know the angle of my 450E seems slow to me, but it is within the cycle time specs, so some of that may be due to design of the circuit.

I did find ice in the cap over the centering spring of the angle valve once. It blocked the valve from full movement in the left to right direction and made it real slow in that direction. Removed the cap, cleaned the ice out, reinstalled and the angle function was back to the same speed both ways. You might want to check that. You can use a propane torch or heat gun to warm the cap over the centering spring. If it moves better after it is warm pull the cap and look for water. It might be sunny in BC but I'll bet water freezes there like it does here.

[kilohertz]

Thanks boys much appreciated.

My serial # is 363000 so it would have come with the 15GPM, thanks for that. Somehow I missed the serial # split when I was looking at the parts catalog. As for twitchy, my blade is so slow with the 15....I better time it to see if it is in spec, but I never run my machines at full tilt, maybe I should try at least a little faster than 1600RPM. I picked up another battery today and when I finish plowing snow tomorrow I will time the cycles. Yes, water freezes here just the same, right now freezing water is falling and expected amount is 6-8" tonight, on top of 4" today, 6" yesterday, a foot over new years, and etc etc.

Again thank you both, I'll review my TM tonight and let you know what I find tomorrrow.

Cheers

PS okay found the cycle times in the manual, would the tilt and angle times be from center to one side, or are they complete "lock to lock" ie from full left to full right? thx