I’m going to explain you how to replace the piston and cylinder on this
Coleman Powermate 21 gallon air compressor first thing you’re going to
need to do is take the plastic cover off of this compressor they come factory
with a plastic cover but this one didn’t come with one because I bought it used
so all you’re going to do is get a crescent wrench I believe this might be
a 14 millimeter on the exhaust line you got four ten millimeter bolts right here
on the top and then it just comes straight up and then the piston comes
out of the cylinder now I made a explanation probably a couple weeks ago describing
how you can do a cheap fix by getting some pliers and bending out this copper
piece so it’ll seal around the cylinder well mine’s just seen its last day I
probably got another two months out of it and then it just started blowing out
more getting thinner so I got a whole new kit and we’re going to take this
piston out I’m going to explain you how to do that and install the kit so here’s
the kit this is the place I bought it from as you can see the master tools
repair and 1244 executive boulevard Chesapeake Virginia so that’s the
address you can just go to master tool repair comm and they have all the air
compressor parts you’re going to need a specific part number you’re going to
look for for this kit for the 21 gallon Coleman power mate air compressor it’s
for 8-0 1 1 4 so that’s the part number for this whole kit comes with the piston
the cylinder and the two gaskets the tools to do the job or pretty much just
a 10 millimeter with an extension you know a 3/8 wrench and just adjustable
crescent wrench and a allen key I don’t know which size it is yet I’ll have to
get it on here let’s see I’m surprised they didn’t give one with the kit there, we go
it’s going to be a 5/32 also one more tool
you’re going to need a quarter inch socket and for these little shroud
there’s one see just one there’s full three actually this one’s missing too
there you go, you’re probably gonna want to swing your sauce of pipe out just a little bit and
pull the shroud off so inside this fan shroud we got another 10 millimeter
right here that we got to take off now it’s going to want to turn so you’re
going to want to push the old piston towards the casting and hold it there
and then just loosen it out and it’s lefty loosey because some of them could
be ready righty loosey instead because of the way it’s going turbos are that
way all right so we got that out kick that all the way out and shroud should
come off now you’re probably gonna have to get a big flat head down in there and
pry it out so let’s get that get that big flat head in there there we go just
kind of pry it out slowly you don’t want to damage it we got to reuse it and
that’s pretty much it for that I guess they got two holes on the shroud so you
can put it any way you want it doesn’t matter alright so now it’s time to take
this piston off and there’s a 5/32 or 5/32 allen wrench on the bottom we’re
gonna have to loosen alright so let’s get the allen wrench in there kind of
hold the top of the piston and it’s going to be lefty loosey so you don’t
got to worry about anything else there we go feels like it’s loose enough and
we’re just going to pull it out just like that now keep in mind before I take
this off I want to explain you this is crucial or else you’ll damage your
piston and the head so you’re probably looking at this new piston saying why is
it flat right there on this one side and tire up over here well the reeds are
here this is where the reeds go in the head it actually goes this way so we
need to pay attention to which way it is on the actual motor so
the flat side on this one is towards the front of the compressor as you can see
right here it’s flat if you get it backwards as soon as you start it up
you’re going to you’re going to end up blowing it up because this parts going
to smash into the head and destroy the reeds
now I explained that you just kind of pull it right out and up and that’s it
so remember the flat part is going towards the front so now we’re going to
take our new piston and right before we do that we want to remember which way
the actual cylinder went all right now that we got our piston out we just want
to check our bearing make sure our bearing is in good shape
you know and not all ratalie and this one’s in really good shape so now that’s
been checked we want to take our cylinder and we want to take the
original cylinder and head and see which way it was put because it goes like this
now we want to look on the bottom and as you can see here one side is fatter than
the other so I don’t want to lose my bolt goes in there so we’re looking
right here this is exactly how it has to go on just like this so just match it up
and that’s the way it’s got to go like that but take some general purpose grease and
just run a light coat on the inside because we want the piston to seat
properly in the cylinder you’ll get a better seal if you just throw it in
there dry it might pre wear a little too early now let’s put the piston in you
got your flat side in the front now drop it down kind of push it out of the angle
to get it over this bearing in order to get this on there it’s it’s going to be
a little tough so you’re going to want on you don’t want to hit the actual seal
so let me get my little mini sledge so I can tap on it I’m going to take the butt
of this mace lid there we go you’re just gonna leave it
like that you can come back up with the piston and I’ll kind of get everything
in there just turn it to where it needs to be now go ahead and leave that
connecting rod loose for now because we got to get the cylinder lined up now
we’re going to take a head and I’m going to take the original one off cylinder
and you can see the gasket and seal it up and everything so we’re going to pull
this gasket up and you can look in here and these are the reeds I was talking
about that’s why it’s got that dish because they kind of stick out further
with these little bumps but actually they’re not too much further than the
surface itself but still that’s the way it’s got to flow the flaps got to open
up so they would hit the piston now we’re on to the original head so we
gotta take these bolts out we gotta change out the seal inside the head so
just go ahead break that loose I had put some high temp silicone on here just to
tidy it over until I could get the actual kit in the mail so I’m just going
to peel this off and then I’m going to replace it with the new seal right here
it’s pretty self-explanatory just throw it on like that once you get this gasket
on there another thing is to clean the inside of this head there’s all kinds of
gunk in there look at my finger and this is the vacuum so where it pulls air so
make sure that you’re getting that actually this sides the vacuum but make
sure they’re both clean this is the exhaust side so it doesn’t really matter
but if you got any kind of little shards from you know just a bad filter whatever
it’s going to get right into that piston and start scratching up the cylinder
wall so make sure you clean this out pretty good that’s the only tricky part
right here you just got to get some silicone kind of DAB it on there so
it’ll stick I’m going to try to do it without it so just put it like that hold
it together and now we got to do the bottom now the bottom you’re probably
going to have to do a little bit of silicone right not because it’s got a
little bend in it if you can get it to lock in
I’ll see if we can’t just throw this on there real quick without the gasket
falling off so first time’s the charm there we go now we’re going to take our
four bolts and kind of just slide them in there because if you lift up and the
seals are going to come undone so you get that piston in there kind of giving
us a hard time there we go all right now just tighten up these ten millimeter
bolts on top hand tight you know got to go crazy by just so they’re nice and
snug a little more than snug so it doesn’t fly through the top and once I
get done with that then we’re going to tighten up this 5/32 allen wrench or
allen bolt and then that’s pretty much it we’re going to push up the line so
you would hardest part for mechanics are is not really the part you’re working on
it’s tools running away so now that we got that done we’re just going to
tighten them up just hand-tight them in an X pattern yeah and over here on the
back inside nothing crazy, they’re only ten millimeters and they’re
real long so and there are aluminum bolts so everything expands at the same
time you’ll feel it stopped you like to grab the wrench at the top not so far
back so it doesn’t put a lot of strain on the bolt put some more on my hand so
I’m oh that’s a good tighten now here’s a real good way to tell it yes some
clearance issues is when you let it up you can actually fully extend it now so
if I want to fire that up it would have ended up just reckon the head
and then they’d be buying me a homemade compressor the company if it was too
long of a rod and they gave me the wrong part number so here’s the problem
the actual cylinder itself is too short they sent the wrong one or whatever so
when I put these two together the original one it’s a whole eight inch two
eighth of an inch to quarter inch higher on the old one versus the new one so I
could just put some washers under here for washers you know flat washers and
it’ll raise it up just a hair I just got off the phone with them and apparently I
ordered the two horsepower kit it’s the same model number but I guess this
compressor comes with two different motors I got the six horsepower one and
they have a two horsepower with the same model number so having said that it’s an
extra twenty some dollars more for the kit the only difference of this kit
versus the other kit is the height on the cylinder that’s it this is a zero
zero five two and this is a zero zero five seven so what I’m going to do is
just put four washers under here to give it that extra height that we need we’re
off about I’d say an eighth of an inch maybe a little more than eight maybe
feeler gauge or so so for as little is a quarter you can save yourself over
twenty twenty-five dollars so I’m just taking these washers and I’m lifting up
on the cylinder and I’m placing them underneath it alright so now we’re going
to just turn the piston and rod make sure we don’t have any more clearance
issues which we don’t so I’m going to loosen this up going to get the rot on there where it
needs to be just going to put your finger on either side of the bearing and
press it so it pulls the rod flush just give it a good tighten I want this thing
flying off just a little close-up of the four washers I put on there they’re
probably like eighth inch thick now we’re going to take our fan and there’s
two grooves in the crank and we’re just going to put it pretty much anywhere we
want to put it honestly just shoot here and it doesn’t matter which one you put
it on so I’ll just put it on my original one and you’re going to want to turn it
there we go so it gets in there then we take our ten millimeter and we just
tighten that up next is the explainer it just goes on the same way you took it
off next we’re going to hook up the exhaust line this is what pumps there
into the tank alright so let’s flip the switch and see what we get.
Source : Air Compressor: “Rebuild Kit Fix” Coleman Powermate 21Gal