Any COM Experts out there, care to chime in?

Boyd B

New User
OK,, Got my ol' 800B running serviced the COM , new filter fresh Dexron. Took it for a test. COM pressure ran about 130 psi lock -up appeared to be working good. as the temp came up pressure dropped off and of course it stopped. Shut it down and let it set, checked the fluids, OK. Started up pressure came back up, moved good and then pressure started fluctuating from 0 to 130, sometime going up to 130 and slowly back down to zero, but mostly hovered between 40 and 80 psi. Even when it went up back up to 130 the lock up didn't appear to work. Almost act like it is sucking air, but no sign of oil foaming. still waiting on my service books, until then any ideas. Thanks
 
I am assuming that you checked the oil level immediately upon shut down before the TC had a chance to drain back. I would check the oil level with it in high gear running idling with the brakes locked, of course and fill it to level running. There should be a cold oil relief on the COM pump that could fail causing loss of pressure, there is also a pressure regulator piston assembly in the COM control valve that could stick causing a similar loss of pressure. The loss of direct drive when hot could be a loose fit between the bushing at the rear of the com unit where the pto drive shaft is carried as dd pressure is sealed at that point by simple bushing to shaft fit. I would clean the pressure regulators to get the pressure stable then deal with the dd as a seperate issue though when you get the pressure solved maybe the other will be ok, Lets hope, mEl
 
I Will CONCUR with You Boyd , it does seem like its sucking air because of fluctuating pressure ,, how much fluid did you put in the 800?.....mEl knows alot that we don't know and I have gained alot from his schooling , and from everyone else too,for so many things , LONG LIVE THE FORUM .. best wishes, jim
 
To be honest guys, I filled it out of a drum with no meter, to the the full mark. Ran it and rechecked the level static, not running. I know I did not drain 4 gallons out of it. I did not drain the Converter, just the case.
 
Did you check the oil right after you shut the tractor off ? The converter on mine will show over full if I check it after the tractor sets overnight.
 

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