ok... update time. First a little back story (sorry if it gets a little long)
I have overhauled several (different) engines over the years, from 1 cyl. aluminum Briggs to 1 cyl. cast iron kohlers to many different American car engines. been playing with them since I was 12 or 13, back around 1980. I am a fleet mechanic for the State that I live in.
but this is my 1st air compressor pump rebuild. and I'd never done an engine where the cylinder jug separated from the crankcase, much like a motor cycle engine does.
I figured it would have to have many similarities to rebuilding an engine but until I did it, didn't know exactly to what extent.
I do not know why, but 20 years ago and more, I used to not care much about collateral damage or remembering how things went back together as I pulled (more like "ripped" and "tore") something apart; but as I get older, while I still like working on things mechanical, I am more afraid of such things as I go, (maybe because I don't have the "bank of Dad" to bail me out any more)
I wind up asking a million questions that in the end wind up being "stupid"/ un necessary once I actually get into the machine and start work, things become more self explanatory as I get into a job. I also find myself having to read and re read written instructions more than once, and still come away saying "huh"? until I actually get inside. then it becomes (more) obvious, what was read. Another "I don't remember being like that when I was younger" sort of thing.
This is my own personal "at home" compressor which I have had around 15 years, and bought it (well) used at that point, compressor is a 1987 model, going by tank certification date. Used it quite a lot for 10-12 years, totally trouble free.
this unit has since been sitting a while, as it started acting screwy on me/ but I had a (smaller) spare, albeit gas powered, compressor to patch me thru. (and gotten back to more old school "hand wrenching") I had forgotten exactly what this unit was doing, ( that it wasn't supposed to be), beyond a motor issue that had me pull the motor and take it in to the electric motor rebuilding shop back then. I did a search here on GJ and found threads that I put up on here 3 years ago, asking "what's up" with this thing. back then I had still run it from my shed, and run an air hose thru the front yard to the garage when I needed air. Quiet that way, put of sight/out of mind, but regular draining and maintenance fell away since it wasn't right there in my way.... I now have it in the detached garage right with me.
I put the motor back on and it no longer tripped the breaker as soon as I turned it on like it had been, but (only) then, remembered that shortly before I quit using it due to the motor issue, it started all of a sudden started taking "forever" to pump up. I dug out the rebuild kit I had gotten and blew off the dust, found the receipt inside from 3 years ago when I'd bought it. Yikes!!! so it was time to tear into it.
Since I had the whole kit, I pretty much decided to do a complete job on it even if it wound up "not really needing it".
As I pulled it apart I discovered part of the issue. Some of the intake valve springs had busted, so they wouldn't seal, would push air that was drawn in right back out the intake valves instead of the exhaust valves. but the seal behind the flywheel was also throwing oil, and I had the rings and gaskets sitting here too, made no sense "not to" put them in.
I went to ebay and bought a dingle ball hone just for this job, in the size of my compressor's bore. Everything pretty much came apart easy enough, spread all the pieces across the bench as they came off. I got it apart and saw 1 piston that seemed to have wrist pin slop. (the compressor was not knocking a bit) so I went to motion Industries and had them match me up a new needle roller bearing and order it. (the other 3 cylinders do not have this, only the 2nd stage piston) I found that pistons and wrist pins are separate pieces on this unit so I ordered the 2nd stage piston and wrist pin, I saw wear on the pin but could not feel it. the piston had a couple of scratches in it too so what the hey.... get one of them comin too. so 2 more weeks go by, waiting for them...
get them in the mail, and go to install them// and decide to pull the flywheel and go after that seal, before I reinstall that piston and rod.
Here was the worst issue that I ran into. Emglo used a roll pin that half went into the flywheel and half into the crank, from the end of the crank. Into a blind hole. so no way to drive that roll pin out. I used a Dremel to wallow out the roll pin to where I could thread in a 1/4-20 tap... then ran a bolt in, and tried to pry that pin out, to no avail.
after stripping 2, grade 8 1/4-20 bolts, I went to go deeper with the tap. Thoughts were to use the bolt thru a socket like a corkscrew to draw that pin out. then I snapped the tap off inside that roll pin. Great. so now I unbolt the pump, and take it to a guy I know that has a laser burner just for such predicaments... he burned the tap out and didn't touch the crank or the flywheel, cost me $40. got the flywheel off and replaced the seal,
now we go back up. put the new rings on and then discover that I do not have a plier style ring compressor small enough. now what? since the jugs have to go over the piston... so I look on Ebay, ask for ideas on here and burn some gas looking for the tool I thought I needed... as it turned out the chamfer on the bottom of the jugs served as its own ring compressor... lots of running around and keyboard time that I did not need to do, as it turned out.
So the last thing is that flywheel, driving it on with the edges of the 1/2-hole each in the crank and the flywheel line up exact so that I can drive the new roll pin in. Took me 3 times of driving the flywheel on with a dead blow hammer and pulling it back off with a 3 jaw, then repeat, to get the flywheel onto the crank with the edges of those 1/2-holes lined up exactly...
but it now lives again.. hopefully now it's ready to run for another 15 years or more.....
