Hi all i have a kobelco 200lc mark 4 approxiamately 5000+- hours. the machine is powered by a cummins 6bt5.9-c engine Last week while loading trucks machine started to overheat,,checked coolant was down about 1.5 gallons inspected engine from above didnt see any coolant anywhere so i refilled with 50/50 mix and problem solved.....Today while running machine starts to overheat,, shut down check coolant and it is down about the same amount but under closer inspection coolant leaking out externally on engine near front upperright side sorry no pics as yet but looks like it could be coming from near where the upper radiator hose enters the block. there appears to be a thermostat housing and sandwiched between that and the block an engine lift ring for engine removal cant really tell if it is leaking between lift ring and block or if it is the head gasket it is definitely not the hose and the thermostat housing to lift ring mating surfaces seem dry but the lift ring to head mating surface is wet. I cant tell if it is that or the head gasket leaking . there is no oil contamination but think could be possible head gasket. Any info if any one has had this problem before or how hard to repair and or parts availibility greatly appreciated.
Dont know with out seeing it but is that lifting ring connected to a block off plate on the intake or something? :beatsme If it was me i would fill it clean the area with some brake clean or somthing that would dry it up good and pressure up the system and sit there and watch to see where it comes out at. Coolant system pressure tester would help...or just let it run.
yeah that sounds right to me to ill do that tomorrow and get a mirror also so i can actually see the area not just feel it
leak Thats where the head gaskets usally leak.. Bob
Don't dig into head gasket just yet, that's a project. The thermostat housing on those are sealed by two lathe cut rings on either side of the lifting plate, not unusual for them to start leaking. I'd replace those seal rings and try it out before I condemned the head gasket. Any Cummins dealer can provide the parts, but you may need the acutal Cummins numbers off the engine ID plate, otherwise, get them from Kobelco.
I've never seen those thermostat housings leak - not that it can't happen........ Water pumps however.......... I know it's alot lower than the thermostat housing - be sure the engine fan isn't flicking the coolant up there. - my 2c worth
That is a bad spot on the head gasket that leaks often. They updated the gasket at the water port and it's better now but if it hasn't been changed yet thats probally it. Try the thermostat 1st. It's a thick rubber ring, has an arrow pointing the direction to install it towards the thermostat and a thin ring on housing side. Yours may not have that bypass hose but the housing, thermostat, seals and lifting bracket will be the same. Good Luck!
Good idea, now that ive seen a break down of it, thats where i would start too. Much cheaper and easier to fix than a head gasket!
some pics to get started first pic upload need a better way than i just did
looks like its the head gasket ..... first 2 pics are of machine, 3rd pic exhaust side between 5and6 cylinders very wet also wet at 1...walked machine to shop 1/2 mile.and positioned engine under chainfall (pics 4 and 5)
another pic oops didnt work
Head Gasket Check NAPA for gasket set price, if clerk can't find it under cummins look under late 70's Dodge PU. Replace all short head bolts (6) these usally break when retorqed .check long bolts,if pitted replace.I have done a gasket in less than 4 hours so first time should be 1 day. good luck Bob
more pics
first pic lift ring and thermostat housing 2nd is removed heat shields and unclamped exhaust 3rd pic removing sheet metal for better access, 4th pic muffler removed and 5th pic closeup between 5 and 6
thanks for all the great info everyone! the exploded view and the replacing the short head bolts are priceless info and the reason i signed on to this website!!I'm going on vacation to Aruba in a couple of days but at least i know where i stand i'll try to post some more pics when i get back and get my parts in
almost forgot any body know head bolt torques on this engine?