Loader Jd 990 and 4700 valve scv bypass

   / Jd 990 and 4700 valve scv bypass #1  

picanoor

Bronze Member
Joined
Aug 8, 2010
Messages
55
Location
angleton texas
Tractor
Massey Ferguson 254 John Deere 990-4700-5310-new holland tn65-kubota l3300-l4200Ferguson to 30,1951-to30,1954, ford 2n 1947, ford 2n 1943 jd 5200, jd 301a, alllis chalmers 45c, John Deere 5200
When I use my fel valve to the right so empthy the bucket on my jd 4700 and on my 990 there is a point that both sides get oil.
I noticed when I was using a tree sheer with a 4" cylinder, small return od rod, on the ram, the cyliner first closes, but then opens after I mover the handle all the way to the right.
Then I tried the bucket and noticed the force was less when the handle was moved all the way to the right, you can hear the oil trough the valve.
Is this a normal?
Pete
 
   / Jd 990 and 4700 valve scv bypass #2  
Yes it is a dump valve. They put it on the smaller loaders so when you dump a bucket of dirt it let's gravity take over and dumps the bucket quick. I believe it's an option when you get the tractor atleast it used to be. So the tractor isn't actually pushing oil into the cylinder that fast it dumps the rod side oil so the bucket can just drop.
 
   / Jd 990 and 4700 valve scv bypass #3  
Yes, normal. Its called "regen" or the "regenerative" function of the valve. Lots of reading here if you search either of those terms.
 
   / Jd 990 and 4700 valve scv bypass
  • Thread Starter
#4  
Thanks for the info , there were some good expalnations in the older articles!
 
 
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