300 hdy pump availability

[daveminn]

My 300 when using it for 10 minuets or so works good but after cleaning the barn with a rear scraper for any more that 10 it wont raise unless you speed up the motor.Has been doing this for some time now.Valves seem to be opening and closing normal.Any ideas and can you still get pumps for them?Thanks!!Dave A

 

[John Saeli]

Dave: Couple things could be going on here. How's the rockshaft cyl.? Will the arms stay up & hold when you shut the engine off? If not, the seals are bad & need replacing. Another thing, is that if your intake pipe has a screen, it could be plugging. Any cover I have pulled, I always found a screen, but some of our customers have told me they had no screen. Pumps, or parts are not available. I always add some 85W140 to that thin oil to thicken it up & add body.

 

[daveminn]

John,The rockshaft o rings were just replaced to no avail.Will check out that screen and see if that is ok next.Thanks for the advice!!Dave A

 

[John Saeli]

Dave: Will the arms stay up when the engine is off?

 

[Joe (Wa)]

I really have a tough time believing that an oil pump that works normally for 10 mins is defective. The oil temp hasn't risen that much in that short interval to be a factor.

I assume your oil level is checked and full before start up.

I don't think you will find an oil intake strainer on a 300 pump, but doesn't hurt to check. Pull the side cover, check pickup tube bolts tight. Check for debris that can interfere with pickup, edge wound filters tend to fracture with excessive back pressure dumping a lot of crap in the torque tube.

Grabbing at straws here, when the eagle hitch is operated near the upper limit the pump relief valve is prone to lifting. There is still some pump pressure while circulating oil in the neutral position (higher if filter is dirty) and the relief valve may not be fully seating while the engine is running and driving the pump. Unfortunately the relief valve is on the left side of the pump and I don't think it can be accessed from the side cover.

If the pump is bad you are probably going to end up with a used one. Be advised the pump was changed at serial nr 6050880, you have to replace the original shift fork, pickup tube, and possibly other drive parts.

Joe

 

[daveminn]

yes,they will hold well.Da

 

[John Saeli]

Dave: A good friend & veteran CASE mechanic said to have you check the linkage at the valve spool. He had one exhibit your exact same symptoms, and discovered a sheared roll pin at the spool.

 

[Case Nutty 1660]

I have a 400B that loses hyd power when the system warms up, I am betting my pump is worn from running it low on hyd oil at some point as the machine has under 2500 original hrs on it, it is the pump on mine I am sure, I have seen the roll pins back out and the system will not work but it does not matter if its hot or cold,,
cnt

 

[daveminn]

I will check that,Thanks for All the help!!Da