SL20 Hydraulic pressure alarm???

[gixxergary]

Hello all,
My 2001 SL20 is throwing a 134 alarm, stating my Hyd pressure is too low. I know its not supposed to get below 100psi, but Im running it at 300. This just started today, and I have never encountered this before with our sl20's. It works for 6 to 8 open and closings, then alarms out. I can reset it, but only get a few more before it repeats. The oil level seems fine, looking thru the top of the tank, because my level isnt working properly.
This may sound stupid, or not, but I have never changed this oil out. The manual states it is supposed to be changed every 24 months. It doesnt appear to have any leaks, and the level has remained the same since I bought it new.
Im going to change the oil right now, and clean the heat exchanger on the top of the motor. Is there any other suggestions you folks would have??? It doesnt appear to be electronic, or it wouldnt work at all. Is it possible for the oil to be too thin with age and heat? The tempurature, if correct,(since the level doesnt work properly, I cant say if the temp is right), is around 115.

Thanks in advance for your replies,
Gary

[gixxergary]

I changed the oil, and at the moment, appears to have fixed the problem. The pump does sound quieter than it did before. ( that could be my imagination also) It may have also been the tempurature. If anyone else has experienced this, please let me know what you found, just incase this comes back, and is only working temporarily.

thanks in advance,
Gary

[Geof]

I have experienced half of it; the half where the pump lost pressure for no apparent reason. I was away on vacation at the time and simply told my people to have a new hydraulic system flown in to replace because we could not afford the down time. The original pump is sitting in my home workshop gathering dust but now I may be motivated to go and change the oil and see what that does.

I guess I should have done it a long time ago but I had forgotten about it.

[gixxergary]

I still have the problem. I appeared to have gone away, but it started again. Any input on this guys???

Gary