420 Hydraulic Check

[OutbackL130]

I'm a newbie just picked up my 84 JD 420 yesterday with plans to restore it. The tractor has 1800 hrs and looks pretty abused, however, appears to run well. I was told the engine had been rebuilt at some point. There is very little I know about these tractors right now. I decided to order a full service manual which am hoping to have by next week. In the mean time I was wanting to ask about the hydraulics.

No idea what kind of maintenance was done so I want to drain the fluids and start fresh. As far as the hydraulics go anything else needed besides new filter and hydraulic fluid?

I see under the hood by the battery is a cap that says trans fluid only. Would this be the fill hole for the hydraulics? What type of fluid do I use? I am confused where the hydraulic fluid check tube is supposed to be and am thinking mine might be missing. There is a barb fitting of some sort on the rear of the tractor near the 3 pt hitch that looks like a plastic tube could have gone on at one time.

Does the same hydraulic pump power the transmission, steering and front/rear implements? Where is the fluid reservoir located?

Does the differential take certain fluid apart from the transmission or is the trans/diff all one unit?

 

[OutbackL130]

Barb fitting on the rear end. Is there anything that goes on it?

 

[OutbackL130]

On the back of this tractor is a plastic tube which mine does not have. Is this the check tube and would damage have occured to my tractor from the previous owner running it without the check tube?

 

[BBO]

On the back of this tractor is a plastic tube which mine does not have. Is this the check tube and would damage have occured to my tractor from the previous owner running it without the check tube?

If you are talking about the fluid level sight glass missing, then the transmission fluid would have drained out some for sure.
Someone would have sure noticed this leak and I would not think it would be pulling properly or the hydraulics working much.
If this has been out a long time and water may have got in there you could have problems.

Change the fluid and replace the tube assembly.
View attachment 420_Sight-Glass.pdf

 

[OutbackL130]

Yes there is no tubing attached to the housing and the fluid sight glass is also missing. I hope they didnt try to run it without fluid if doing so will cause damage to the transmission. The hydraulics all seem to work.

Think it would be ok to replace with clear 1/4" Tygon tubing? The original tubing from John Deere is no longer available.

 

[OutbackL130]

Where does the tubing run after the sight glass?