IH 666 Injection Pump Problem

helenthe

Member
My IH 666 has the American Bosch injection pump, I have a good flow of fuel to the charge pump from the primary filter, but fuel will not pass the charge pump either with the hand primer or cranking the engine. Thoughts please.

John
 
I assume by “charge pump” you mean the injection pump? What’s the rest of the story? Was it a running tractor then just stopped? Or has it been setting not started for a while? Same as 1030 Case you posted about, critical parts in these injection pumps tend to gum up and stick during periods of non use. Then the pump does not function ..pump fuel.. properly.
 
Check valve in the primer pump probably stuck. At the base of the primer there's a plug to remove for the check valve. 7/8 wrench I think
 
Yes both the 666 and the Case 1030 sat unused for a few months last winter. The 1030 has a history of B-20 fuel but not the 666. It was a running tractor. I swapped the primer pump in the 666 with a working pump. By the "charge pump" I am referring to the transfer pump at the rear of the injection pump. Something stuck in that transfer pump it seems but I am reluctant to remove it without knowing more what I'm getting into.
 
Charge pump, transfer pump,same thing ,different terminology. Just have to remove the 7/8 plug and their is a spring and a spool. Very easy
 
Charge pump, transfer pump,same thing ,different terminology. Just have to remove the 7/8 plug and their is a spring and a spool. Very easy
It might also be the inlet valve INTO the supply pump rear, I've seen those stick closed too. Just need to remove that line and use a nail or punch to knock the nylon valve forward off the brass seat it's stuck to. The pressure control valve can also stick too, but not as common as the inlet valve does.
 
Hello Dieseltech, glad to see you posting. When you have time you might go back to the thread about my Case 1030 Bosch pump. It is now off the tractor and on my bench and I'm wondering about any possible soak procedures to save rebuild cost. Thanks.
 
Hello Dieseltech, glad to see you posting. When you have time you might go back to the thread about my Case 1030 Bosch pump. It is now off the tractor and on my bench and I'm wondering about any possible soak procedures to save rebuild cost. Thanks.
I've saved a few inline pumps that had stuck plungers in the past without tearing the pumps down, but one must be careful not to damage the plunger feet. Clean the outside well, then remove the two bolt pump side cover. Turn pump drive gear BY HAND, and watch each tappet/plunger unit each tappet SHOULD go up/down as the gear is turned, any that DO NOT go down means that plunger is stuck in the barrel and on ANY inline pump it only needs ONE to stick and the rack won't move freely as it needs to. E-mail me at [email protected] and I'll give you a number to call some evening so I can explain more.
 
On the IH 666 pump, I removed the 7/8 cap and spring. Couple strokes of the hand primer, I could hear something come free. I also gently pushed a drift into the transfer pump inlet and could feel the nylon valve move. The hand primer will now suck up fuel but still not push it through the transfer pump on the down stroke. ??????
 
On the IH 666 pump, I removed the 7/8 cap and spring. Couple strokes of the hand primer, I could hear something come free. I also gently pushed a drift into the transfer pump inlet and could feel the nylon valve move. The hand primer will now suck up fuel but still not push it through the transfer pump on the down stroke. ??????
Then one of the valves INSIDE is out of place, the pump assembly has FOUR check valves used ONLY for the hand primer system to work, two inside and one each at the inlet port and outlet port. I see this happen on pumps in for repair on occasion. If the INLET valve and pressure regulating valves are OK reconnect the INLET LINE and REMOVE the OUTLET LINE and blow air into the fuel tank to pressurize it, if fuel will come out the outlet, reconnect the line, pressurize again to bleed the filters if needed. Open throttle 1/3-1/4 and try starting engine, if it starts it's good to go. The GEAR PUMP does not need the valves to work, IF the INLET one is OK and not stuck, only the pressurizing valve needs to work for gear pump operation. On any M100 pump , ALWAYS open the throttle 1/3-1/4, hot or cold to start engine, NEVER AT IDLE. The oil controlled excess fuel cylinder and governor assembly works together for easier starting, but NOT at idle.
 
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Well, with throttle 1/3 and outlet line removed, I pressurized the tank. Low pressure with shop vac outlet. Nothing. So I pressurized the inlet line at the filter end. Still nothing, not even a drop at the outlet.
 
Well, with throttle 1/3 and outlet line removed, I pressurized the tank. Low pressure with shop vac outlet. Nothing. So I pressurized the inlet line at the filter end. Still nothing, not even a drop at the outlet.
Shop vac IS NOT enough, at least 5/10 PSI is needed. The 1/3 throttle is NOT needed for bleeding the filter INLET.
 
Neglected to say I used higher pressure when pressurizing the inlet line. Will try it again tomorrow with no throttle. The hand primer will suck up fuel but completely resists down pressure.
 
Neglected to say I used higher pressure when pressurizing the inlet line. Will try it again tomorrow with no throttle. The hand primer will suck up fuel but completely resists down pressure.
Again, primer resists going down BECAUSE one of the valves INSIDE THE PUMP assembly is out of place, I've seen this happen several times in my years of injection pump repair. The gear pump will still move fuel even though the primer does not work.
 
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Dieseltech, thank you for your efforts to help me. The primer does not work and cranking the engine also does not deliver any fuel to the transfer pump outlet, even though there is a good flow of fuel to the inlet. I am tempted to remove the transfer pump from the reat of the injection pump to see what is stuck in there but have always been very cautious about injection pumps.

A friend of mine worked on a Roosa pump for six months, disassembling and reassumbling numerous times, plus on and off the tractor to test since he did not have a test bench. In the end he was forced to send it to a rebuilder. He wanted the rebuilder to tell him what was wrong with it, what he had missed. But Fred would only say, "you took it apart".

Are there any other steps I can take or tests that I can do?

John
 
Dieseltech, thank you for your efforts to help me. The primer does not work and cranking the engine also does not deliver any fuel to the transfer pump outlet, even though there is a good flow of fuel to the inlet. I am tempted to remove the transfer pump from the reat of the injection pump to see what is stuck in there but have always been very cautious about injection pumps.

A friend of mine worked on a Roosa pump for six months, disassembling and reassumbling numerous times, plus on and off the tractor to test since he did not have a test bench. In the end he was forced to send it to a rebuilder. He wanted the rebuilder to tell him what was wrong with it, what he had missed. But Fred would only say, "you took it apart".

Are there any other steps I can take or tests that I can do?

John
That gear pump SHOULD still work even though the hand primer won't, but you won't see any fuel while cranking. If the FRONT HEAD/HOUSING is full with fuel engine should start and run. One must be careful taking that gear pump apart, and most don't know what to look for anyway. I check for that trouble on every M100 pump I get in for repair, then verify pump assembly works as it should on the test bench.
 
You're right, I would not know what to look for in the gear pump unless the function is simple and obvious. The atory again from the beginning is that the tractor would not start after sitting several months in winter. I tried the primer and it did not work. II changed filters and put in fresh fuel, but primer still would not work. I replaced primer with one known to be working, no change. Unless there is something more to try, I guess I'm going to have to send the entire pump for rebuild. My direct email is [email protected] if you would like to send a quote.

You gave me an email address previously which I will contact once I have fully studied the action in the Case 1030 pump.
 

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