Dozer hard to start

[Delmer]

Yes. Also the priming pump piston acts on the same pumping chamber and uses the same two valves, if the seal on the priming pump piston is leaking, and you can see that it has in the pics, then air can get in there also. I think they have also seal when the pump handle is screwed all the way down, so make sure that cap is screwed down as tight as you can with your fingers.

 

[Tenwheeler]

Yes. Also the priming pump piston acts on the same pumping chamber and uses the same two valves, if the seal on the priming pump piston is leaking, and you can see that it has in the pics, then air can get in there also. I think they have also seal when the pump handle is screwed all the way down, so make sure that cap is screwed down as tight as you can with your fingers.

I have seen those hand pumps mentioned do that also. The pressure relief valve I mentioned is in the fitting just in front of and below the number 1 injector line. It has a steel and a rubber hose connected to it. I have had a good bit of problems with algae in older machines. An inline automotive filter protects the pump but requires frequent changes. Killem will take care of the algae but then you need to buy filters be the case. The supply pump does not need a filter that fine anyway, just a screen or bird catcher. The big spin on, you are replacing anyway, filters the fuel for the engine. My local fuel injection company sells a clear inline filter with a screen in it. The screen can be removed and cleaned. That is how I would start.
1. New fuel filter and inline screen.
2. Check and or replace check valves, #3. If you sand them that's like 2000 grit paper on a piece of glass.
3. Inspect pressure regulator, I thank it has one.
4. If problem persists replace hand primer pump.

 

[coastbuster]

I have seen those hand pumps mentioned do that also. The pressure relief valve I mentioned is in the fitting just in front of and below the number 1 injector line. It has a steel and a rubber hose connected to it. I have had a good bit of problems with algae in older machines. An inline automotive filter protects the pump but requires frequent changes. Killem will take care of the algae but then you need to buy filters be the case. The supply pump does not need a filter that fine anyway, just a screen or bird catcher. The big spin on, you are replacing anyway, filters the fuel for the engine. My local fuel injection company sells a clear inline filter with a screen in it. The screen can be removed and cleaned. That is how I would start.
1. New fuel filter and inline screen.
2. Check and or replace check valves, #3. If you sand them that's like 2000 grit paper on a piece of glass.
3. Inspect pressure regulator, I thank it has one.
4. If problem persists replace hand primer pump.

Changing filters as we speak,then removing #3 valves and looking at the pressure regulator. P.S. what should I be looking for on the regulator?

 

[DMiller]

Correct me if I am incorrect but would any pressure regulator be under or in the fittings at the front end of the pump? I do not remember there being one of these, just a flood and flush type systems when in service. May be a discharge check inside the fitting at that front end fitting, look for damage if has one but is on the filtered side of the fuel system.

 

[Old Magnet]

The valve is located under the fitting just below #1 fuel injection pump. Not much to look for, either it works or it doesn't. Should see filtered fuel but I suppose some piece of junk, rust or whatever could wind up in there.
Part # is a 1183818 if needed.
Is there a fuel pressure issue?

 

[DMiller]

What is considered is bleed off, possibly trash in the check valves on transfer pump.

 

[Tenwheeler]

Changing filters as we speak,then removing #3 valves and looking at the pressure regulator. P.S. what should I be looking for on the regulator?

Should not be able to blow through it or maybe turn it with inlet pointing up and pore it full of fuel. It should not bleed fuel off in 30 minutes to an hour. You could put a pressure gauge tee in spin on filter hose if you really want to know what pressure is doing but should not be necessary. If you cannot find a serviceable primary (screen) filter JD 5425- 5530 Ag tractors use one with 5/16 ends. Ford ,just before Sterling, trucks with C series Cummings used one with 3/8's ends. They look just like a gas filter, are easier to service than a supply pump screen and have a much larger capacity.

 

[coastbuster]

View attachment 173773 Need a tractor s/n. Looked up the D3C Series III and they apparently started using the early style pump again. This would be for years 1993 to 2002. This would be on the 3046 engine 5XK1-up. Should have caught the six injector pump initially, oh well!!

To Tenwheeler,Delmar,Old Magnet et al. I replaced the #3 valves,the whole primer pump assembly #7,washers #5 and filter #13. Thanks to you guys I now have my old Cat back to normal. Starts in 2 seconds. Does anyone have the parts list diagram for the 1078528 injector pump? While I'm at it I want to replace the pressure regulator but need the part #. Thanks again boys,couldn't have done it without you. Dan

 

[kshansen]

Is there any chance of a complete S/N for this machine? Sorry if I missed it when scrolling through the posts above!

 

[kshansen]

Is this what you were asking for?

 

[kshansen]

Or this one of the priming pump?

 

[coastbuster]

Is this what you were asking for?

Yea,the pump breakdown is it. The regulator valve is #43 part # 1183818. I'll replace that too. Thanks KS

 

[Tenwheeler]

Yea,the pump breakdown is it. The regulator valve is #43 part # 1183818. I'll replace that too. Thanks KS

They almost never go bad. If they do it is usually a piece of trash, from a filter or hose change, and can be cleaned out.

 

[coastbuster]

Well guys,Dozer has gone back to hard starting again,worse than before. Awaiting the new pressure regulator valve. There are two lines leaving the valve. One rubber I assume goes back to the tank. The other is metallic tubing which wraps around the back of the motor. Does anyone know where the metallic line ends up?

 

[coastbuster]

The valve is located under the fitting just below #1 fuel injection pump. Not much to look for, either it works or it doesn't. Should see filtered fuel but I suppose some piece of junk, rust or whatever could wind up in there.
Part # is a 1183818 if needed.
Is there a fuel pressure issue?

Don't think there is a fuel pressure issue because once it starts it runs perfectly.

 

[Old Magnet]

Good question on the metallic line. Looks like it may be a return line coming from injectors. Shown as hose at the injectors themselves then becomes steel line.

 

[Delmer]

Have you tried priming it before you try to start it? Is there any rubber hose in the suction side of the transfer pump?

 

[Tenwheeler]

What if anything did you do with the inline, automotive gas line looking, filter? Clean out your filter 13 and try it again.

 

[Old Magnet]

Seems to be a plague of this issue with D3's, same symptoms. No solution yet but collapsed suction line hose and/or blockage of the same 5G4109 screen in the fuel tank are next on the suspect list. This after changing filters, transfer pump valves and cleaning screen in lift pump intake port. Still the same problem, runs for awhile then fuel pressure is lost. Plenty of bleeding and does not have a priming pump.

 

[DMiller]

Beginning to wonder if we are seeing a result of ULSD again. It does seem to tie into many fuel system woes these days. Have wondered if the fuel suppliers cut it back yet again adding some other mystery agent that does not like mechanical systems?