John Deere loader very slow to raise

[jrod1981]

I have a John Deere 1530 with either a 143 or145 loader I cant remember exactly which but, the loader is very slow to raise. The hydraulic pump was rebuilt recently and filters and fluids have been replaced as well. I had read where someone was having similar problems and found the closed center control valve was to blame. Where is this part and how can I test it?
 

[buickanddeere]

Somebody probably hosed you for the front pump rebuild. That
front pump is usually the last item to require service.
Where is the loader oil supplied from the tractor and where
is it returned?
Has the loader always been slow or is this a new problem?
Does the tractor have an independent hydraulic pro and the
high/low transmission lever on the dash?
Anybody check the transmission oil screen?
Was anything found in the trans oil?
 

[rrlund]

If the pump went bad and there was any junk in the system,I'm thinking there might be just a little chunk of something in the destroker valve in the pump. Left hand side of the pump,down in the top if memory serves me right,there should be a valve with a roll pin through it for a handle. Screw that in with it running,then turn it back out all the way. If there is anything in there,that should flush it out.
 

[jrod1981]

We bought the tractor without the loader and later put a used loader on it. The loader has been extremely slow since we put it on. From memory the loader supply is tapped into a line supplying the rear scv and the return is tapped in at the filter housing. We had the hyd. pump rebuilt thinking it was at fault but, that was not the fix. How would one test flow to and from the loader control valves?
 

[buickanddeere]

The front pump needs a strong supply of oil from the trans
pump or the front pump will never have output
Measure port pressure at the transmission and flow to the
front pump.
 

[Eric Benton]

You may have a loader with a open center hydraulic valve on it. Some of them have a plug you can put an oring on and change it to a closed center valve. The easy way to check this is to crank up the tractor and just let it run for 15-20 minutes and then put your hand on the loader control valve. If it is really hot or will burn you then you have a open center valve and you are dumping (hi pressure internal leak)your hydraulic right back into the filter cover. On a closed center system the valve should be barely warm .