i should have included that a regular grease gun is high pressure and it is possible to blow your seals if they aren't already broken from time. but having said that i prefer to use a lever grease gun over the pistol grip type because as you pump you can feel the slightest resistance and that tells you it is time to stop. it really is easy to feel when the roller is full. now on the other hand when the seal is already bad and the reason for corn head grease over the 000 you won't feel any resistance at all. you can pump until the grease just comes out and you can see it. just go gentle at first to see if any rollers have good seals or not. the advantage to corn head grease is it is solid until the slightest movement then it liquefies and will flow into the bushing and as soon as the movement stops it becomes thick again so it stays in the roller for a long time.

For those of you who have never been inside a Cat roller, here is a pic of my D4 7J top carrier roller bearing, you can see the curved oil groove in the bronze bearing to carry to lube, the bottom rollers are the same design.

the seals should not blow out as one is installed in reverse to how a oil seal is "normally" installed this is so it acts a a relief point. bad seals or incorrect installation yes it could happen.

solution is simply use the adapter another member posted a pic of it would be easy to make with a few fittings and a drill.

trainzkid88 wrote:

the seals should not blow out as one is installed in reverse to how a oil seal is "normally" installed this is so it acts a a relief point. bad seals or incorrect installation yes it could happen.

solution is simply use the adapter another member posted a pic of it would be easy to make with a few fittings and a drill.
 

Oil filled rollers use a duo cone seal that is basically two steel rings pushed together using orings. Older grease filled rollers use a bellows type seal. Older style seals can be damaged by over pressurizing the roller with grease. Usually it is the bellows part of the seal that is damaged.

A bellows type seal I just removed from the front idler of my D4 7J, as you can see the rubber bellows are blown out, alongside is a new one, the D2 front idler, and D6 4R / 5R bottom rollers use the exact same bellow seal.

As pointed out above, I would never trust myself with a regular grease gun trying to lube rollers with bellows type seals. Using the volume pump and a little care one can note a slight increase in resistance on the handle of the volume pump and it is time to quit pumping. Too much pressure and too much grease makes the bellows type seal worthless as it is rather easy to destroy the bellows as pictured above. (Of course age makes them deteriorate also.) My D4 is not luxurious enough to have oil filled rollers.

it is very evident that the roller is full using a regular grease gun with a lever handle. just go slow and when you feel the slightest resistance stop. don't try this with a pistol grip grease gun because the return spring takes away from the sensitivity. now mind you that i am using corn head grease or 000 in the grease gun and not nlgi#2 also note that the button head on my grease gun has a place where a relief valve can be screwed in also.