xring 223

Member
Got a 640 and after it sits for a few days the hyds. don't work for a while usually 2 or 3 minutes and raising RPM's what is going on am I loosing pump prime?
 
I would guess you are losing prime.
A lot of times if people split the tractor for engine work or a clutch they don't replace the orings at the pump manifold.
You might try replacing them and see if that works.
Inspect the manifold closely to see if it has been bent ot twisted too.
 
I agree with Ultradog, It sounds like you are losing prime due to a suction side leak.

You can try replacing the manifold 0-rings. I prefer to get the square rings from CHN. They seem to seal better than a standard O-ring.

If that doesn't work, you probably have a blown seal on the pump's wobble shaft. Most likely a worn surface on the the wobble shaft too. Its not a simple job to replace the seal. If you want to tackle that, post back and we can help.
 
[i:654c4848f0]" I prefer to get the square rings from CHN. They seem to seal better than a standard O-ring."[/i:654c4848f0]

Agreed.
I put regular o rings in my 4200 when I changed the pump a couple of months ago.
Pump was chattering and losing prime.
So I bought the square ones from the dealer Friday afternoon on my way up to my land.
$6.29 for the pair.
Changed them out when I got there and did some discing Fri evening.
Lift is working good now.
But now I'm having carb/fuel problems.
Arrrgh.
 
pulled plug out of pump oil at plug hooked clear line to bleed no air reinstalled plug started tractor again rear hyd took a minute and half before movement detected light load on engine
 

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