Is my hydraulic pump in trouble?

[sh40]

Fiat 100 90. It has been stood for the last 3 or 4 months doing nothing. Went to go agitating today and lift was only working fair. Changed hyd filters but it made no difference. Also plenty of oil in the back axle.

It was doing the following:

1. Lift would go up and start jumping as its raising.

2. It would then start jumping when in the up position and get worse with revs. It might also act normal. It just depends what mood it was in.

3. It might decide to not go up at all. All spools would give up. Maybe after moving lever up and down for 30 seconds might get it going again.


Is it the pump or is there some valve in trouble? Dial under the seat is twisted to the last the correct way.

 

[ridger]

Sounds more like its drawing air somewhere, remember our 9090 once changing the filter, and the ring not coming off the filter, so there was 2 rubber rings then between filter and housing, also they can draw air where the pipe goes onto the pump on side of engine

 

[Fievel Farmanimal]

Sounds more like its drawing air somewhere, remember our 9090 once changing the filter, and the ring not coming off the filter, so there was 2 rubber rings then between filter and housing, also they can draw air where the pipe goes onto the pump on side of engine

I don't know how the pump is in this, but maybe it can draw air pass pump's shaft seals too?

 

[Timbo]

The hyd pumps are very weak and poor on these, if its original I'd be looking to replace it - about a 30mins job, and you can get a slightly bigger capacity one which helps the pitifully poor flow they have !

That said it sounds like its sucking air somewhere... Mine will judder when the oil is cold though - fine when warmed up.

 

[sh40]

Would I hear it drawing air if it was? Or could I feel it if I put my hand near all the places mentioned. Pump also gets luke warm pretty quickly, never mad hot though (although I hadn't been working it super hard either) and I think I heard the pump groan at one stage.

 

[ridger]

Would I hear it drawing air if it was? Or could I feel it if I put my hand near all the places mentioned. Pump also gets luke warm pretty quickly, never mad hot though (although I hadn't been working it super hard either) and I think I heard the pump groan at one stage.

No, it won't be very obvious. I'd stick a new pump on it, on a loader tractor they used to do 3 years and weren't that expensive

 

[sh40]

Can I rule out that any valve is stuck by the info I have given?

 

[ridger]

Only thing you could do is get her warmed up and tip a trailer a time or two to get oil all around her

 

[sh40]

Only thing you could do is get her warmed up and tip a trailer a time or two to get oil all around her

What would that tell me?

 

[ridger]

See if it's still jumping or pumping steady

 

[fiat 9090]

If you put a pressure gauge on it and if it doesn't reach 2500 at half revs then your pump is f...ked

 

[farmer pickles]

What sort of filters are you using? A friend had a similar problem and changed the pump and still no better. Changed to a different brand of filters and no problems since.