JD 550G slow hydraulics

1989 JD 550G sat for couple months. When started, blade acted like it wasn't going to lift up, then did slowly. Same with tilt & angle. This summer replaced 3 busted hoses & added hyd. fluid. Can see no leaks on the ground. After it warms up it responds but none too fast. Sight glass has never worked; no one has ever seen the hyd. fluid in it no matter how much is added. Its either overfilled or under filled. Without draining it & refilling with the specified amount I don't know how you'd tell if sight glass was clogged up or not. Buddy says try a new filter first.

The first thing I would go for is the suction strainer in the reservoir,you will need a clean container and drain the hydraulic oil so you can reuse it if its not contaminated,to get to the strainer open the tool box door,disconnect the suction line from the tank outlet and remove all the bolts holding the access plate to the tank,remove the plate and you will find the strainer on the back of it,usually the strainer is washable,wash the strainer in gas or diesel and if you have air give it a blow,when clean put it back in the tank,see the gasket is good,have a look at the suction line to make sure its not damaged or squashed causing the oil flow to be restricted, while the tank is empty take out the lens in the sight gauge and either clean it or replace it,often why the oil can't be seen is that it is over filled or low,put the oil in till it's half way up the gauge,see how its reacting now,if it's still slow it could have a pump issue,try this first and if its no good come back and we can go through the other possibles,there are a few different setups of the model,the early models had a round plate for the suction strainer and the later ones a square plate so you need the serial # to know what it is.
Good luck
AJ

WOW! thanks a lot. That's great. I've got the owners manual but its not helpful like a parts manual would be.

Here is a online parts catalog.
http://jdpc.deere.com/jdpc/servlet/com.deere.u90490.partscatalog.view.servlets.HomePageServlet_Alt

Great. thank you.