Machining out SEIZED Head Gland | CAT 785 Dump Truck Cylinder

how you going guys Kurtis from Cutting Edge  Engineering today's job we have a 785 outer   hoist rod to try and salvage and what i mean by  salvage we need to try and rescue this tube the   tube's worth about 15 grand so well and probably  worth the exercise to try and save it so this is   a hollow chrome tube this is the first stage of  a 785 dump truck hoist cylinder so on the truck   there are two hoist cylinders they're both used  for lifting and lowering the bin for the truck customers stripped it off the machine to do a  general repair on the seal kits in the cylinder   so as they've tried to remove the gland that  holds in the next stage of the cylinder it's   actually bound up it's pretty common with these  sort of things and the style of thread they use   they do use a buttress thread since the gland has  locked up in the in the barrel it was best to just   leave it there don't try and screw it back into  where it was and don't try and take it out anymore   what the plan is now we'll put it in the machine  we're going to take a boring bar i'm going to   start to machine the inside of the gland out  so we're pretty much just going to turn it all   into swarf hopefully after we do that we'll be  then be able to salvage the thread that's inside   the customer has supplied a brand new gland or head that we can test fit into it right so one of the things that could have  helped with the cause of this thing locking up   uh would be moisture buildup so these cylinders  are actually upside down on the truck they're   not in a standard configuration even though  they are upside down there is a gap around   the gland that can actually allow moisture and  dirt and stuff like that in so if anything did   get in there it would have created rust which  then would have caused everything to start to   expand and that's probably the reason why it all  locked up but we won't know exactly what happened   until we start to get it apart so we're gonna  set up in the machine and start machining it out that's pretty gnarly oh that's it there look at that for a scratch it's pretty deep righto guys so it's set up in the machine  now we've got it running on the steady   uh you'll notice there is a ticking noise as  it's actually running in the machine we have   discovered a nice big scratch in the chrome so  being that scratch is as deep as it is i'm not too   concerned now about damaging the chrome because  the customer is going to send this one out to get   it re-chromed so i was unaware of that but after  talking with them it will be re-chromed so i'm   not too concerned about the chrome work now so if we  do end up peeling a bit of that up with the steady   which does happen because  there is a bit of damage there   yeah so now i'm not worried about it  let's get on to machining the inside out i'm just going to shorten up that boring bar it' doesn't need to be that long 38mm to come out [Music] righto guys so i've chucked a dial on the  end of this barrel just to show yous how   out of well deformed it is  from the thread picking up about a point two of a mil run out there so it'll  be interesting to see after we get deeper into   this gland whether that shrinks back down and you  know has minimal run out or it stays like that now the barrel is stronger than the  gland so the gland is now compressing and the barrel's going back to somewhat of a round shape yup we're through that bit point 8 of a mil [Music] that's all that's all dust and  dirt that's what we're looking for it's really hot one bit try and get all that [ __ ] out now there's something under there that's where it all started [Music] what you got righto guys so we have successfully removed  the gland uh there is a little bit of damage   on the internal threads so we are going to  attempt to chase that thread down we've got   a bit of rust we need to clean out  and a little bit of the area of the   barrel that's actually missing thread so  what we'll do is we'll set the boring bar   up we'll time everything back in and we'll  take a few very very minute cuts to try and   clean up all the surfaces so the new gland  fits without any problems or interference right oh so those of you who don't know what  a buttress thread is your standard 55 degree   thread looks like that well a buttress thread is  90 degrees on the back and then it rakes forward righto guys so we've cleaned  up the barrel the gland does fit   you'll see a lot of the damage inside  there in the threads is caused from rust   one of the things that could have been done  from the manufacturing and design stage   was a c-section o-ring or some similar  something put around this ridge around   here maybe one in here maybe one on the face  there are many different things that you could   have done in the design stage to eliminate such  problems as this knowing full well moisture gets everywhere [Music] can't even tell there was a steady there right we're good yeah right ready   as they were undoing the end gland that holds in  the second stage second or third [ __ ] [Laughter] I can't remember the customers brought it in it's  hard to explain so on the hoist oh um yep yep on the truck there are two  hoist cylinders they're both used   for lifting and lowering the bin for the truck [Laughter] Yep after we a bit of an oversight but gives me something to do [Laughter] ready [Laughter] you've got all dirt on your face right there like all there what is it it's just all grease  and dirt really how bad is it pretty noticeable  just wipe it off it doesn't wipe off it just smears beautiful [ __ ] off [Laughter] shut up hose that sounds terrible yeah that's going to get annoying it's [ __ ] sizeable whatever it is [ __ ] [ __ ] oh it's very [ __ ] hot ow ow ow look at the [ __ ] in there   [ __ ] an insert already there was a bit of [ __ ] that was stuck in there that i couldn't get out   hold on to your tits oh dear poo a little pallet there aye he's a special dog

Channel: Cutting Edge Engineering Australia

Views: 899,057

Keywords: cutting edge engineering australia, machinist in australia, machininst, abom79, cee australia, Cat 785, caterpillar, dump truck, 785 dump truck, mining truck, caterpillar wrenching, seized cylinder head, cylinder gland, hydraulic cylinder, hydraulic cylinder repair, cylinder repair, manual machining, machining, boring on a lathe, machining cast iron, buttress thread, buttress threading, internal thread on lathe, machining thread repair, thread chasing, chasing thread on lathe

Id: m7aYtiX8_-k

Length: 25min 49sec (1549 seconds)

Published: Fri Jul 30 2021