International 100 Timing

AMBAC Model 100 pumps are common on International tractors. This timing procedure is the easiest way. Please call us for questions.

To time this pump, first find out what the timing degrees are for your engine. Sometimes it is on a plate or sticker on the engine itself. If not, get the number off the block and call me or any International Harvester dealer. Typical is 15 degrees to 18 degrees. Often somebody has marked the flywheel for future reference.

Now it’s time to line up 3 marks; the flywheel, the pump head gear and the pump. Some tractors use the front crankshaft pulley instead of the flywheel. Put the flywheel to degree (or front pulley). There is a cover on the flywheel housing to remove to see the flywheel.

Now look under the 4 screw cover on the pump and find this mark. If it is not there, turn the engine one complete revolution, in either direction back to degree and look again. The mark just needs to be in the window, this indicates that the pump is on number one. The ink pen in the picture is on the mark.

Ok, now let’s line up the pump. Remove the front cover to access the pump drive gear. There is a plug to remove to view mark or view it from the front. If it is a little off, don’t worry. They guy before you could have miss-timed it, happens all the time. The pointer should point at the mark. Make sure when you install it after rebuilding that it’s right on.

Now remove the pump. When we rebuild the pump we will give it back to you locked in time using a  locking device screwed into the bottom of the front housing. The front gear will be left loose on purpose to allow you to install the pump without any interference from the helical cut drive gears. Install the pump, check all marks, tighten the bolts on the front drive gear, remove the pump locking screw and install the pipe plug in the hole in the bottom of the front housing. Pump the hand pump on the back of the pump until you hear fuel running back to the fuel tank or until you get a charley horse in your arm; whichever comes first! Now loosen all six injector lines at the injectors and roll the engine until you see fuel. Tighten the injection lines and start the engine.