Graco Merkur 45:1 and XTR 5 Airless Spray Gun Maintenance and Rebuild


so much more simpler than the mysterious that’s a neat design there it goes
yeah that’s gonna let come off oh cool well I’ll tell you this
puncture disassemble is easy now our smaller prompt as a Mercker it’s still a
great coat but it just goes under a different brand name and the owners
manual refers again to another manual for the specific pump that manual tell
you how to take it apart and this comes apart relatively easy now there’s a ball
valve and so I don’t want to drop that because it might just roll right out of
there we’re gonna get a look inside and see if this pump these any cleaning like
the other one did okay sure enough there’s our little ball
sitting right inside there I’m already glad we did this because this ball has a
coating of paint on it I bet that’s not normal
might mean that I should’ve ran a little more fluid through it not too bad in
there that’s where that ball seats got a little bit of gunk but nothing that’s
hard it’s soft there’s the galleys for the paint to go
on past that check valve that seal looks in good shape you know there’s the top
glance unlike the bigger pump this is a lot
simpler it’s got a lower assembly in an upper assembly that’s where they split
apart easy enough it says when you take this part be sure not to damage the
shaft inside there it is okay we got to have soft jaws for this next step so a
couple pieces of wood will give me soft jaws you know we’re gonna remove this
wet cut from this down so it’s got some flats on it too so use my little bitty
crest or ranch on there the seal should be behind that and we
can pull the piston out I just got a little buildup in it not too bad oops
okay all those seals in place and don’t damage the side of that piston yeah this
would be a cinch to clean this up and this in underneath the wet cup has a
spring okay there’s the packing seat and I like taking the picture of this stuff
when I take it apart makes me sure I know how to put it back together now
there’s even a little over in underneath out we’re using xylene as our cleaner
today which is the thinner for the epoxy paint that I use it’s a good idea to take the o-ring off
before you clean around it you’ll get it cleaner and you won’t damage the o-ring
any and we clean all that out okay there’s another bulb out behind
that nut that nut sticking out with a hex wrench we’re gonna clamp up by these
flats down here on the shaft don’t clamp up anywhere else on that shaft destroy
it take that over hang out we don’t want to
damage it though next thing is a seat laughs thanks ball
should drop out it looks in good shape all right this is clever as shit when
this thing pushes down paint flows up through that ball and throughout these
holes and into this part of the chamber when it pulls up of course it’s pushing
that paint out when it goes back down is pulled in twice the volume of this
piston so it not only has enough paint to charge the top but it also has enough
paint to create pressure on the downstroke and it pushes paint out to
the sprayer so it works both ways okay ball goes in seal goes in just the way
it came out rusty side down over in goes in nut goes
back on you need a torque wrench you got a big torque rest and put some adapters
on it this is the top seal pack that’s what
you’d be replacing if you had new seals to put in I don’t so we’re using it
spring on top of that and insert it upside-down once that spring has tension on it hold
the seal back in place even look down in there and see that spring in place no
it’s not this up now we put the packings into the other round the spring last
side of the first steel packing downward and all of our packing seals where I
leaned this piston rod can come out while there make sure it flows through
that packing well okay and lower cylinder goes back onto
the upper cylinder and compression for the spring once a
95-pound stewart and that’s a lot of torque now we didn’t take the seed out for this
ball but it’s there and we’re gonna leave it the ball goes in make sure this
overing gets a little lubricant maybe Lower East goes on what’s the tour grab that advice flaps okay rain drops in there and the fitting
going out to the hoes no tapes needed cuz that o-ring will do the sealing snug
that up we go back on the pump now this thing is called a wet cup you actually
fill it with a lubricant that keeps the paint from drying around the piston as
it goes in and out so it’s a maintenance thing and they sell the particularly
quitin here you can use motor oil but will probably get into your paint
eventually and it will cause fish eyes you can also use solvents like xylene
but that’s gonna vaporators stuff which is probably what you ought to do now
those go down to the bottom this threads on right there we can push this down
against the distance tighten that up and we screw the cylinder up and they want
the top of the cylinder flush with the plate there a little more right there snap that into place shield back on so
you can’t see anything that’s going on it’s kind of fun out of it big see the
fill for the wet Cup there should that seated will and the manual tells you about this
regulator it’s actually the feed a gun that uses air as well as paint we’re not
using that gun so it doesn’t matter in our case beautifully no got a leak in
there gonna steal something up tighter yeah completely missed this step
supposed to torque this 255 pounds and I just have hand tight you know and they
asked for it to be torque after the cylinder was all assembled so this is
after it’s all simple right with the cover off and make sure it’s not leaking
this time that looks good good all right worrying about xylene okay I’ve had this
stuff on my hands no problem poured out of a hose into my lap and you know when
the twig and berries get in contact with it it will heat you up okay and and not
in a good way okay feels like you had a lot a lot of
sex like way too much here’s what I’ll do to your penis
actually this is Betsy’s arm she has really delicate skin I’m a delicate
flower yeah she got sent on her so be careful with this stuff your mileage may
vary well ain’t working we’re getting paint
on the boat we’re gonna use a roller to roll it out I’d like to plan there’s
nothing it works in one way over what all the one gown can fell over damn it I
wouldn’t had enough’ to make it anyway you’re hoping to get this on but we did
confirm and that pump ain’t up to snuff yet so I think what we’re gonna do is
we’re gonna buy a set of packing seals for it that must be the problem it is
it’s working good I know the roller actually works really nice with it all
right I dropped the pressure on it you can see that while it goes up and down
it’s pumping on both strokes so when it’s on a high pressure when it has to
push through the nozzle it has to do that so I think that’s my mind it’s
slipping around the the gas gets in there so we need a new packing seal set
but that’s one Oh easy thing to do we know how to take it apart now should be
that clean inside the coffin we’ll get a chance to take a look and see ya on the
displacement pump I need this seal kit for that well there it is one hundred
and fifty three dollars but on eBay it’s only 60 buy it now commit and all this
great cool Mercker I also looked up there’s a number on this cartridge here
and it has a filter that goes to it so we’ll get one of those if it’s a got a
gray coat mark on it you can bet that you can look up the part
there’s the bottom that’s solid paint yeah
okay it’s not a filter it’s just a bunch of pain in there okay seal kit came in so we just took it
back apart again so what we do is we carefully take it apart so we can see
the old seal set and lay the new seal set out around it we know that that goes
to that one particular right there goes into the throat and there’ll be another
one for the piston there’s our stack put together like the manual says and what’s
interesting is that’s not what was in there there were fewer seals in this dating in in the cup suit Jericho there’s no leaks okay we’re good the question now is will
it move paint it’s always done this okay all right we’ll sacrifice a chicken
tonight and pray to the boat God this is the morning we’re doing the test
see if this 45 to 1 if you pulled off well it started working it takes a long
time like 7-8 minutes to pump it all the way through the hose before we gotten
coal tar at the end down the pressure’s up so looks like it might work you got
that gauge on what it’s doing is its spraying a couple
times pretty good and then it kind of loses energy you can see it goes into
like a fan pattern like on his fingers and that means the pressures too low so
what we’re going to do is we’re going to change the tips to a 519 from a 525 it’s
a smaller tip and hopefully that will keep the flow down there’s one good spray
it starts fingering out you see how the mist goes in and out to
a stream that’s locked at pressure there there died you can actually feel it kick
the handle when it dies yeah yeah that’s not any good but that’s all
the tricks we have up our sleeve for this pump it’s just not enough for this
cult are it could be you know a ball in there or could be we put the seals in
not quite right that I don’t think so but that’s doing pretty damn good it’s
almost there you know it’s almost like a star for air I’m gonna set the max air
pressure on this thing so that it’s higher about a do 150 psi okay now write a trick so we’ll just
roll it on there’s about a quarter pane 50 feet of 3/8 inch hose you get that
back minutes starting to give me a little thinner now most of the really
nasty stuff out so I’m gonna switch to clean stuff we’re on that till we get to
clean through it yeah that’s almost clear now we’re getting there now the paint will actually settle out
of this dirty xylene they’ll clean itself up and we can pour back off the
clean stuff save a lot of it you see it’s already getting thickened the
bottom of that bucket there well since my daylights going and my guns leaking
we’re just gonna take apart two guys see if we can stop it from leaking okay that
pulls up comes down then we can take the barrel off now there’s a flat right
there on the handle so you can grab onto that there comes some guns come with a
filter and if they do it’ll be on that side of that area mine doesn’t but mine
is leaking I suspect it’s in the needles which are between this cap and that cap
little force okay I got it loose just a bit of spring in there there it is yeah
my valve seat this part here is stuck on there good so I’m gonna use a wrench to
take it off not a crescent wrench so I can put more pressure on it uniformly
5/8 inch wrench yeah it goes now it’s leaking this ought to be weird cuz that
ball has to sit nicely on that seat right there
so that ball is actually the end of the needle and we will take that out and
that is stuck give our cap a bit of persuasion oh here’s where I screwed up
while holding needle use tool to remove needle retainer that’s threaded on there
so I’m buying a new needle which I think I’d need anyway and a retainer cap so I
ripped the threads out of it and push the needle out yeah there’s a lot of
carrete on that ball looks like it’s in pretty good shape no nut holes the
grommet around the backside of the needle we can take that out
that gasket if there was paint back in here I think that’d be the problem
there’s a little bit of debris back in here but not that much there’s a 5/16
inch nut in there I can stand a little cleaning seat below that can be pulled
out with a pick mine looks in good shape so I’m just gonna clean around it a
little bit leave it there another chance to play in xylene it’s gonna fin to have
a little bath now that needs to be talked about 25
pounds not the same for that in and also for
the handle barrel there we go not leaking anymore in the
glue is holding wine this up without getting any on my penis nice do that
again once is enough in my lifetime we’re
gonna try our mercury out again but this time with a Murloc too and it’s good to
note that this thing fills up even without a screen it’s got a slug of
paint in here from the coal-tar that we tried to shoot through so I would say
all filters need to be changed every time changed or cleaned at least that’s
as big as the one that was in it last time so that’s just one load of paint
will produce that as a slug in the bottle I say it’s a good trap for heavy
deposits in any case but that’s even with cleaner running through it so the
cleaner doesn’t get the bottom of these things cleaned out now it’s 94 degrees
out so I’m thinning this with a mirror coat 101 which is a thinner that helps
the paint not go off quite as fast if it’s 94 degrees out today I could use a
little more time in pot life great thing there we go yeah it’s real little thing I seriously think the cleanup takes
longer than the painting when you got this gun working is a lovely gun you

5 comments

  • TAP001

    Saw you on the Coolest Thing I ever Made. What a great idea. I will watch your channel. So cool!

    Reply
  • roxborotomm

    Better rebuild video than the Graco site.. side note, when we spray intumescent coatings, we remove the filters from the pump, not sure if that is your issue

    Reply
  • John Palmer

    I love how you show what it takes to maintain spraying equipment.

    Reply
  • Tim Robinson-Lunn

    Just a thought a lot of these spray machines need lubricant for the piston, most shops sell it but sewing machine oil works as well needs it to stop over heating, also there is a product called liquid shield a blue coloured liquid used as a after wash helps lubricant the line and piston stops it from drying inside

    Reply
  • Deftones Dsm

    Your groin absorbs chemicals better than most of your skin. Hence always wear boxers/underwear cause if you get chemicals on your pants your skin WILL absorb it. If you work around commercial industrial chemicals protect your skin. There's bad shit out there that can fuck you up. Like cancer etc slow painfull death eventually

    Reply
  • Jon

    Looking great!

    Reply

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