# Sluggish Case 485



## Glenwood Coleman (Oct 6, 2018)

Hello

I recently bought a 1986 Case 485 and it has been sluggish to start and run, especially under load. I can run it for a very short period of time in low range with a bush hog but it eventually starves itself out of fuel and shuts off. It will not handle high range at all. I replaced the fuel filters and blew some air back through the line into the tank, drained all the diesel and replaced it with new fuel. It was suggested to me that there may be air in the line? Does anyone have any suggestions on how to bleed the air out or what steps I should take next? full disclosure I'm a newbie at equipment repair, any and all suggestions are appreciated.

Thanks 
Glenwood


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## RC Wells (Dec 26, 2008)

Your Operators Manual will have a set of instructions on how to bleed air after filter changes. Just follow those.

However, if the tractor is shutting down then restarts after setting, without bleeding air from the injection lines, I would suggest a fuel flow test between the filter and the injection pump. Let the fuel run for at least five minutes. If you have unimpeded fuel flow, then it is likely you need to have the injection pump serviced.

If the fuel flow is restricted, test it at the valve at the bottom of the tank.

The metal tanks of this design tend to drop rust into the bottom of the tank and block the fuel valve, or pass rust and scale enough through to block the filter inlet. Or, if fuel treatment was not used they grow algae and develop clogs of crud that slither down and clog the outlet.

Blowing air back through the fuel feed line will stir up the sediment in the tank, but unless the tank is removed and inverted as it is washed out, the crud will just settle back on the tank valve and restrict fuel flow again.

Rust and sediment settling in the bottom of the tank is a common issue with the IH and Case IH tractors with that design of fuel tank.

On the other hand, if you are having to bleed air out of the injection lines after the tractor shuts down before it will restart, check the gaskets on the fuel filter to be sure they are pliant and properly installed. This includes the moisture drain at the bottom of the filter, if so equipped.

If you have good flow from the filter and no need to bleed air after stalling, it is likely the injection pump that is the problem. The Bosch VA has a regulator valve that will fail an allows the pump head flow to diminish to the point that the pump will not pump the required flow or pressure, which leads to power loss and stalling. That pump also has a control plunger and throttle shaft system in which the springs and/or O rings fail. The VE Bosch injection pump is more robust, but they also require service particularly if untreated diesel fuel has been used.

I would not try to service either pump in a home shop, and removal to ship off for service requires the Service Manual be followed.


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## thepumpguysc (Jan 25, 2015)

I have to know what type of injection pump it has..?? to better diagnose..
They put several diff. types on that machine.. A pic of the fuel system would be very helpful.. injection pump, filters & lines..


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## Rstanza1 (Jul 19, 2021)

thepumpguysc said:


> I have to know what type of injection pump it has..?? to better diagnose..
> They put several diff. types on that machine.. A pic of the fuel system would be very helpful.. injection pump, filters & lines..


I have a Case 380B Sounds like it's Missing real bad on one Cyi. This is a Variant of the 485, Pump #1329100C91 Can you recommend a site for a Break down on this pump? I was told they had a Purge Valve on it? I've looked and all I've found is ads trying to sell a rebuilt one @41800.00 Plus! Thanks in advance, and Thanks for allowing me to Join Ron Costanza


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## thepumpguysc (Jan 25, 2015)

That injection pump is a rotary pump.. it has 1 main pumping unit that feeds all the cylinders.. so if it’s missing on 1, it’s more than likely an injector..
I suggest swapping the suspect cyl injector w 1 that’s furthest away & see if the problem follows the injector or stays on that cylinder..


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## thepumpguysc (Jan 25, 2015)

To find the skipping cyl..
Start the engine and get it skipping, one by one loosen the line up AT THE INJECTOR.. kinda like pulling the spark plug wire off your old car.. 
The good spark plug will make a difference in the way the engine sounds.. the bad one won’t..
Be sure to tighten the line back up once u check it..& move to the next one.
Once u find the bad cylinder, take the injector out and swap it and do the test over again..
If your lucky, the skip followed the injector..
If that’s the case, I DONT recommend getting 1 outta 3 rebuilt.. get them all done at the same time..
They all had the same kinda fuel ran thru them.. the same amount of hours on them..
Here’s hoping for the best..


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## Rstanza1 (Jul 19, 2021)

thepumpguysc said:


> To find the skipping cyl..
> Start the engine and get it skipping, one by one loosen the line up AT THE INJECTOR.. kinda like pulling the spark plug wire off your old car..
> The good spark plug will make a difference in the way the engine sounds.. the bad one won’t..
> Be sure to tighten the line back up once u check it..& move to the next one.
> ...


Thank You so much, I'll get back with results soon as I get back to the Farm, maybe a week or so.Ron


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## Rstanza1 (Jul 19, 2021)

Rstanza1 said:


> Thank You so much, I'll get back with results soon as I get back to the Farm, maybe a week or so.Ron


What is a Ball park on having that Pump and injectors rebuilt? A Time line and will you be willing to do it if I can't find someone locally?


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