# 1975 ford 3400



## Slaughter (Jun 3, 2014)

I have a 1975 3400 and when I use the PTO with the brush hog, The rigid hydraulic
line blows loose from where it enters the differential. Other than this the tractor seems to run and operate just fine.
I have had the local Ford Dealer out and replaced the line, However this line does not thread into the differential, it appears to be a compression fitting only. 
Any suggestions or help would be appreciated.


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## stickerpicker (Sep 16, 2003)

Slaughter said:


> I have a 1975 3400 and when I use the PTO with the brush hog, The rigid hydraulic
> line blows loose from where it enters the differential. Other than this the tractor seems to run and operate just fine.
> I have had the local Ford Dealer out and replaced the line, However this line does not thread into the differential, it appears to be a compression fitting only.
> Any suggestions or help would be appreciated.


Is there a question why it blew out or another question?


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## Slaughter (Jun 3, 2014)

I am sorry for not being clear, the line continues to blow off, or out of the differential, even after having replaced it and having the dealer install it.
I would like to know why the hydraulic line keeps blowing out?


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## sixbales (May 18, 2011)

Howdy Slaughter,

Welcome to the Ford/New Holland Tractor Forum. 

Attached is a picture of the high pressure line connection (pump end) on my Ford 3600. The connection on the rear end side appears to be the same. Your's should be similar.

If you look closely, there is "hub" welded (probably silver soldered) on the tube. There is no way it can blow out. I suspect your connection has broken off, and the previous owner has cobbled together a connection that will blow out. Probably a ferrule connection?? Or is the tube popping out of the hub?? Please confirm. 

If you will look on the pump end of your line, the connection should be the same on both ends. 

I think you will have to replace the line. A used line should be fine, if you can find one in good condition.


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## Slaughter (Jun 3, 2014)

I am not sure that I am describing the line correctly. On the 3400 I have, the line run from the pump at the left rear of the engine, up over the engine and back to the differential. I has a fairly sharp 90 degree turn and goes right into the differential, directly under the right ( as you are driving ) foot rest, and is kinda concealed behind the emergency brake rods etc. As I recall there is a large hex head insert that threads into the differential, and the 3/4" tube or line seems to just slip through the hole in the center, When I ordered the replacement line it did not have any fitting on the differential end. I think however I did replace this hex insert at the time. I might be able to get a photo of it though, if I could figure out how to attach it to an email


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## sixbales (May 18, 2011)

Have a look at the attached parts diagram. It's probably not the same setup you have, but the piping should be the same. Tell us what pipe you are having problems with.


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## Slaughter (Jun 3, 2014)

Thank you, It is number 6, of the top exploded view, The one that has the right dark arrow pointing to it


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## sixbales (May 18, 2011)

I obtained the following explanation from *Mike(NE Ohio):*

*"The line goes into the nut and through the rubber donut then through a small metal ring with an L-shaped cross section. Then the line seats against the shoulder of the larger nut that is screwed into the housing. The L-shaped ring caps the ID corner of the rubber ring to keep it from squeezing into the large nut. I had it on the outside of the rubber once and it always leaked a little, until I figured it out. When you tighten the nut the rubber compresses and grips the line. I hope this description makes sense to you." *

Study this carefully. The tube has to go completely through the outer nut and bottom out in the inner nut screwed into the differential housing.


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## sixbales (May 18, 2011)

Additional comment from *UltradogMN*:

*Those nuts are a well known failure point.
Part of the problem is when you remove and retighten them the little metal part that actually grips the tube digs into the tube and damages it. Then it doesn't hold well and leaks.
One fix that has worked for me is to remove the line, buy a new nut for it and install it onto the line. Then take a drift and drive it into the tube to slightly expand the OD of the tube.
That darned nut is about $40 at the dealer and about the same price on Ebay, etc. *

I would do exactly as Ultradog states.


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## sixbales (May 18, 2011)

You can get these parts on the internet from Messick's Farm Equipment. If you have a tubing flaring tool, you can put a slight flare on it to allow the L-shaped "gripper" to get a good hold on the tube.


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