Another "I did something stupid" thread....

[mongo]

So I am still putting together my 3100 using an EngineTech rebuild kit. I pulled the new EngineTech oil pump cover off so I could have the new pickup tube welded/brazed in place. I pulled the rolled pin out of the pressure bypass hole (the stupid part is I wasn't looking directly at it and didn't have my thumb over the hole) to remove the spring as the heat from welding will remove the temper from the spring. As I pulled the roll pin I felt something hit my arm and heard something small land in a pile of my garage debris.

As far as I know there are only two parts being held in place by that roll pin, the spring and the piston. I have both of those. I just have no idea what hit me in the arm the exact second I pulled that pin and it is freaking me out. I don't believe there was a washer/cap/plug on top of the spring and I don't remember there being another spring coiled inside the large one... but SOMETHING hit me. Could have been a flying insect as they are starting to come out.

I pulled apart the original GM pump and I have the exact same parts in the GM pump as I have for the EngineTech pump.

Have I lost a part? Has anyone pulled apart their Engine Tech Oil Pump before? I would hate to finish this motor just to find out I am missing a spacer or booster spring or something and my pump goes into permanent bypass mode....

[Guest]

There is a cap between the roll pin and the spring, at least there has been on every pump I've dealt with.

Also you don't need to remove that spring to tack the oil pick up to the pump body, because that's all you need is a tack or two. It does not need to be welded solid.

[mongo]

I was thinking it could have been a cap or washer but whatever hit me had some real velocity behind it (after travelling about 3 feet) and that spring is only compressed about 1/8 of an inch. As that seems unlikely, AND the GM pump has the exact same parts (no cap) I am thinking something else hit me. I would really like to be sure and hear from someone who has direct experience with one of these pumps. Sure, it appears to be an exact copy of the GM pump but that doesn't mean the spring they had made was a little out of spec on the weak side so they shimmed it with a cap or a washer.....

Just tacking it was my original plan... but it didn't end up going that way and what is done is done at this point...

Since we are on the subject... and I have to pull my rear main cap off again as I forgot to put sealant on the back lip... I have two additional questions:

The rear main seal comes with an O-Ring that is supposed to be for the oil pump. Where? There hasn't been one ANYWHERE I can find on the other two GM pumps I have pulled. Even Fel-Pro adds one to the pack with their Rear Main. Is this a throwaway part on the 3100?

The oil pup came with a plastic drive shaft "guide" which seems to do nothing. Is it just there for ease of installation or does it have a legimate purpose?

[mongo]

I have finally found a reference to that oil seal o-ring on the net... but SPECIFICALLY for the 1994 motor. I am pretty sure at this point it is a simple throw away item for the other motors. That plastic/nylon guide also seems only to be a convience item so even though I am using it, it does not appear necessary in any way.

Now I am just down to wondering about that Engine Tech pump and if something flew out or not....

[mongo]

I called a rebuild shop who told me that the only parts behind the roll pin were the spring and the piston which I have. The tech did tell me that he personally puts a small washer in there when he puts them back together as he does not care for the spring riding directly against the roll pin....

It looks like I am all set at this point to finish buttoning up the bottom of this motor... unless someone posts a dire warning on here before I get it all done