72d belly mower for 3520 drops

   / 72d belly mower for 3520 drops #1  

deerecat

New member
Joined
Jun 5, 2010
Messages
6
Location
Ireland, IN
Tractor
John Deere 3520
Hello Everyone,
I have had my new tractor back to the dealer two times and they keep telling me, John Deere says the hyd, cyl is to raise the deck and not hold it up and use the locking pin, John deere says in a service letter that if the deck bleeds off in under 7mins that something is wrong then, I think that it should hold it up for 8hrs at the min. The dealer timed it and it takes 25 mins. to bleed off. They did fix the 3pt from bleeding off and thats great, But I'm not very happy to spend all that money and the deck Bleeds off:mad: . Anyone else out there have a problem like this. Other then that I love the tractor and loader,
 
   / 72d belly mower for 3520 drops #2  
my 72d mower on my 3520 also bleeds off in 2 to 3 mins. the deck only uses one hyd line to the cyl. on my old 4410 with a 72" mmm it did not bleed off but it used two lines to the hyd cyl. ???????? beats me...........bud
 
   / 72d belly mower for 3520 drops #3  
One way (single hyd line) cylinders are known for bleeding off over time. I have a hyd lift kit on my 2320's 62D drive over deck and it bleeds off so fast you can watch it go down like in 45 seconds...It did not make me happy but the dealer says there is nothing they can do.
 
   / 72d belly mower for 3520 drops #4  
Hydraulic cylinders without a pilot valve leak down. Adding a pilot valve would probably add 8-10 dollars to the cost of the valve. John Deere must feel the extra cost would prevent a sale.
 
   / 72d belly mower for 3520 drops #5  
Hydraulic cylinders without a pilot valve leak down. Adding a pilot valve would probably add 8-10 dollars to the cost of the valve. John Deere must feel the extra cost would prevent a sale.

It is a one way cylinder. Check valve won't work. As far as I know, it takes pressure from the other hose to create enough pressure to open the check valve.
 
   / 72d belly mower for 3520 drops #6  
So we need a locking pin to keep it up? I have a 72" but I would imagine the 72d is heavier so it comes down in a lot less time than mine does. That is one of the next things I wanted to work on.
 
   / 72d belly mower for 3520 drops #7  
If you have the trird scv, why can't you put a regular cylinder on the mower deck to hydraulicly raise or lower? My 72" deck on my 3320 works that way. It stays up when raised.
 
   / 72d belly mower for 3520 drops
  • Thread Starter
#8  
What I mean by locking pin is the deck height pin, if I got to get out of the seat to move it , Why just not flip the two levers and remove the gauge wheel pins and remove the deck all together, It has seem that i have anwersed my own ? . It is a Poor set up By Deere and one they need to fix. I work on coal mine equiment all day long. and if they had a cyl bleed off that quick we would have to fix it, Most of CAT spec of cyl drift is 1/4" in 3 mins. If the mower deck is so hevay that the cyl that on there won't hold it up put on a bigger cyl.. I love everything eles about the tractor but there about to get it back if they don't get fixed. Its not that i'm layz, Its that I spent $3500 on a mower deck that bleeds off :mad:My inlaws have a 445jd mower and the deck stays up on it and i dove it 4miles to my house before i got my 3520 to mow. I can't drive the 3520 back to the dealer 1 1/2 miles up the road with out the deck droping three times, thanks for everyones help:thumbsup:
 
   / 72d belly mower for 3520 drops #9  
If you have the trird scv, why can't you put a regular cylinder on the mower deck to hydraulicly raise or lower? My 72" deck on my 3320 works that way. It stays up when raised.

This sounds like what we need to look at for a solution. My 3520 uses one line off of the rear scv. Why not use the 3rd funct. ports that are closer to the deck cyl. anyhow rather than run a longer line all the way to the rear of the tractor:confused: This would make more sense IMO. Mine leaks down quickly also.:thumbdown:
 
   / 72d belly mower for 3520 drops #10  
If you have the trird scv, why can't you put a regular cylinder on the mower deck to hydraulicly raise or lower? My 72" deck on my 3320 works that way. It stays up when raised.

jd670, yours works like my 3 yr old 7 Iron 72" mmm on my 3720 cab tractor. It takes several hours to leak down. The cylinder which raises and lowers the deck has two lines to/from the rear scv -- not one line.
 
 
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