# CASE International 484 BOSCH Seal Leak



## lawnphysics (May 1, 2011)

I am pretty sure I have a seal leak on a BOSCH Pump on my grandfathers 484. We are losing a good amount of diesel and I would like to get this fixed. I am posting pictures. Is this something I can fix myself. I am very mechanically inclined with hydraulic pumps/seals and gasoline engines. I just rarely work with diesel and this is the farm workhorse so I do not want to break it!


I can visibly watch diesel ooze out of the seal area the green arrow is pointing at inside the black box.

Is this a simple matter of ordering new seals and replacing, or will I have to have the pump/injector overhauled? I hope overhauling is not the case, because I can not afford to do that at this time. I would prefer to order the seal and replace it if this is something I can do!


Thanks!


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## cyrush (Apr 20, 2010)

Theoretically it should go to a Bosch dealer for repair, but if you can get the bits you may be able to repair it yourself. ???

IH & Case sometimes showed a parts breakdown, but rarely carried these parts, usual supply source is the Bosch service network.

It is not usual to get a leak here, it could be because there is a restriction in the return line pressure. The pipe fitting on top of the pump is a banjo fitting , the banjo has avery small orifice, if this is blocked it could be the cause of the problem ??

The pump runs with quite ahigh pressure inside the casing because the speed of the pump is controlled by a hydraulic governor


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## cyrush (Apr 20, 2010)

See att, Injection pump parts breakdown.


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## lawnphysics (May 1, 2011)

I am pretty sure that the Part # 30 - Part #3078366R1 O-ring, Distributor Head. Is the Main issue. I am tempted to just keave it alone. I have been using the tractor more lately and it does not seem to be leakin as much. I also changed from off-road dyed diesel back to regular diesel. Seemed to help. Granted, it still leaks though.


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## SVanDee (Oct 15, 2010)

Had the same problem with my IH 484 last year. Well, I'm not sure it was that exact seal but an injector seal was leaking fuel. The shop that overhauled it and several people that use heavy duty diesel equipment a lot told me the ultra-low sulphur fuel that appears to be all you can get now is to blame. Diesel engines that weren't designed for it relied on sulphur in the fuel for lubrication of seals and moving parts. 

Adding a lubricant to your fuel might keep the problem(s) from getting worse. I've read and heard that you can just add some engine oil - even used since the fuel filter will take out any particles. I'm skeptical. I'd be inclined to use a product specifically intended for that purpose. My diesel supplier claims to have started adding a lubricant to his fuel about the time I got concerned so I haven't investigated products and don't have any specific suggestions for you. Maybe someone else will.


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## PSJ (Sep 20, 2011)

I use this in my fuel. Because the engine runs smoother, sounds like it isn't laboring as much, I can mow about another 5 acres on a tank of fuel. I forgot to add it once and almost ran out of fuel in the field. It is also a pump and injector lubricant. PJ

Power Service Diesel Fuel Conditioner. 



LINK== Diesel Fuel Supplement


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## copotay (Jul 24, 2016)

I hate to wake up an old thread but I have a 1985 385 with the same pump and same problem. I was reading where cyrush is saying there could be a restriction in the return line so I undid the banjo fitting a bit and diesel is flowing out from it. Would that mean it's not blocked and I could take it apart to change #30 oring?


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## Dougal Boyd (Sep 4, 2021)

copotay said:


> I hate to wake up an old thread but I have a 1985 385 with the same pump and same problem. I was reading where cyrush is saying there could be a restriction in the return line so I undid the banjo fitting a bit and diesel is flowing out from it. Would that mean it's not blocked and I could take it apart to change #30 oring?


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## Dougal Boyd (Sep 4, 2021)

I to have the identical problem with my I H 684 diesel pump as copotay and someone else had. . I can see the crack where the diesel is seeping out. I have 4 screws holding the end housing that ditributes fuel off to the injectors. Is it easy enough to undo these four screws and replace the seal, it looks to be quite thick, as in 3 mm. Sounds like there is an o ring in there some where too. Taking the pump off sounds a real mission with Pulleys etc to disengage ?


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## thepumpguysc (Jan 25, 2015)

As soon as u take the 4 screws out & pull the head back.. the pump implodes and all the bits come falling out.!!!
The pump is meant to be worked on w the pump off the engine and the drive shaft pointing down..


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