On the Cummins 4-390 engine and a Case 580SE. We removed the injector pump but could NOT get the little pin loose to go into the hole. My pin is plastic and I suspect the pin has been broken off inside. So we rotated the pump so that the keyway is straight up on top. Inside the pump we see it aligned with the "G" mark. Now looking at this I wonder how anyone could ever get the pump out of time no matter where the engine is at when it's removed. So long as the engine is never rotated with the pump off and the keyway is aligned to reinstall the pump. I am told the engine rotates 2 times when the pump turns one revolution. Is this correct? We are about to reinstall the pump and I am wondering if timing will be an issue. The pump has an alignment mark for the timing cover and you have to align the keyway to insert it. One pump guy tells me that it's almost impossible to screw up the timing on this engine with the CAV pump. I do not understand the significance of the pin or why it matters.
Hey bowen, it's true, it's almost foolproof to remove & refit the pump on those engines. You are able to rotate the pump slightly on the mounting bolts. This advances & retards the timing by about 5 to 10 degrees. You can also line up the scribed lines on the flange when refitting & the engine will run. However, if you want it to be EXACTLY correct, it needs to be on TDC & the letter in the pump window lined up. The idea of the timing pin was an advanced idea by the CDC engine designers to assist doing this type of job. The pin would lock the engine at TDC, the pump would be fitted with it's timing marks aligned, also locked in place. When the pump was securely mounted both locking pins would be released - prime & play. Yes, it rotates at half crankshaft speed - it is a 4 stroke engine, injector fires every second time piston gets to TDC.
Most of those units that I worked on had a keyway with no key installed. The pin for the engine timing fit into a hole in the idler gear and many times the nub on the end of the pin was sheared off by someone not being real careful. You should be able to see the nub on the timing pin.
We did get the thing back on & running with no problems at all. I think all my leaks are fixed except for one easy one from the tank supply. The barring tool is OK, but it takes a long time to rotate the engine around 2 revolutions with the short stroke from a ratchet.
I told you it wasn't hard..with some instructions and a few hand tools.. Did you do it yourself or get some help?? IF I wasn't busier than a 1 legged man in an ass kickin' contest, I would have taken a road trip to give you a hand..
A little of both. I did have help getting it off and the o-rings/gaskets replaced. I did some cleaning and painting to make it look like new. We did not use the new cover that I had bought. We had a question about the torque setting for the the front mounting nut, but I found this in the service manual. It says 48 ft lbs, although I had previously been told 75 ft lbs. It's a pretty thin nut. This seems like trouble with the engine getting out of time, if anything slipped. Without the key-way I would have needed to read way more... I suspect the nut on front would need to be real tight.
The pump is all back on and no more leaks. On the little pin underneath. It seems to be broken inside the timing gear cover. (You can push it in/out in any engine position.) Should I take it off and replace it? Looks to be mounted with two star allens. I suspect it has a gasket that I might need to order also.
Don't remove the 2 star bolts unless its leaking, the holes are elongated and used for marking/finding TDC. You can remove the clip that holds in the pin with a screwdriver, just pop it out...remove the pin w/pliers..it has an oring on it also.. Easiest was I found to get the end of the broken pin out of the gear is.. heat-up something small like a "scribe or screwdriver blade" get it cherry red and push it into the broken ***, its plastic, let it cool for a minute and pull it straight out..works every time..