1486 hydraulics

[Harry in Ky]

A man asked me yesterday about a problem with his 1486. He recently had some work done on it (like $3500 worth) involving new pumps, and other stuff. He doesn't speak English very well and doesn't really know all the details of what was done., so I don't have much to work with.

The problem now is that since the tractor came back it works fine on level ground but freewheels when going downhill, The steering and brakes are lost, and has no engine braking. He said he was told there may be a problem with an internal tube somewhere that is letting one of the pumps suck air when the front end is lower than the rear causing those functions to fail until the tractor levels out again.

Any ideas on something that might relate to those symptoms?

 

[Janicholson]

The money might have not fixed the issue. The quick solution that might make it work correctly is to over fill the Hytran by 5 gallons (not a typo).
This floods the pump intake and prevents the symptom. It is actually a standard fix. However it is disguising the fact that the spent money resulted
in failed, as well as, unsafe operation. So it is a real decision that must be made whether to take it back for correction (especially if this was the
original issue) or do the 5 gallon patch. Jim

 

[the tractor vet]

It is possible that the suction tube that is in the rear end housing that dips down into the sump has a crack where the mounting bracket is welded to the tube , or you could be sucking air at the hyd Filter . So the easy maybe it will fix it is a new gskt and O/ring at the filter housing . Wha you want to look at when you remove the filter housing is where the bolt go thru it and if they are HUMPED up , they need to be flat on the gskt side . Also each time a new filter is installed the big O/Ring needs replaced . Now as for the pick up tube here it gets harder and more bucks as the cab has to go to remove the rock shaft housing to get to the pick up tube . aslo here is something else to check is if the MCV was removed by someone that does not know I H tractors then there is a chance that the sump check plug was lost or atleast the little spring fell off . . The cheap way out is like Jim said dump and extra Five gallon to her .

 

[Harry in Ky]

To be fair I'm not really clear on why all the work done was needed to begin with. It's my understanding this problem was not there before the work.

I have heard of the "five gallons extra fluid" trick many times with a number of different model IH tractors. It's my understanding the front pump supplies the steering, brakes and TA clutches, yes/no? It draws fluid from the rear housing through the tube in question and the hydraulic filter?

 

[MARK ROBKE]

I know some one with a 986, who lost every thing going up a steep hill
puling a round baler. It was low on fluid. Flat ground was ok. I would
sure try that or overfill first. Mark.