We have replaced the negative & positive cables with heavy welding cable. New gear reduction starter. Modified for fit of group 31 battery…. After each of these changes will start perfectly (with high cranking speed) for a day or two…then no start without boost with a second group 31. Very warm here today; barely started after 2 hour shutdown. If holding crank will barely turn over then speed up a lot (I believe due to the gear reduction starter) and start. When tilting cab for starter replacement saw a negative cable from starter to frame…left it alone as figured starter well grounded to engine/frame. Did see some green corrosion…could this be the problem all along? I (confess) bad at electrical! Have a basic meter here at camp… As a side note our newly acquired Hitachi EX100-1 (1994) starts within 1/2 second down to -8c (lol!) did install two new group 31’s… Could the trouble be hydraulic loading of engine? Have noticed a slight ‘twitch’ of boom occasionally when starting.
Check all your battery connections for corrosion to start with. Remove and clean the starter to frame cable. How far down does the battery drop with the test leads on the batttery only while cranking and how cold was it. If you jack the machine tracks off the ground when cranking and the tracks move then you have something powering the tracks when it should'nt. My guess is bad connections or weak battery but maybe insufficient charge. Maybe post a picture of your batteries as I am not there but unsure if you went from top post battery to stud post battery. Simon C
Not only should you make sure the engine to frame ground is clean and the entire cable is sound, also make sure the battery to frame cable is sound and the connection to the frame is clean. I have seen, on multiple occasions, the engine to frame ground cause intermittent slow cranking.
Will check the engine to frame ground today….missed that one! Thanks!
It was the engine to frame ground! Had one spare welding cable at camp; sandpapered mounting surfaces to bare metal/bolted on. Spins over very quickly now with an almost instant start.
Also gave the machine a little love, oil change…. Had some Delvac 15w40 at camp. New Donaldson oil filter. Was surprised to see (once removing brass cap) a spring loaded drain on oil pan. Have never seen that before. I guess to address issue of overtighted drain plugs? Have sure seen that before… I do not have a ‘release’ cap on the machine so just held a small Allen key to release oil. One ruined pair of cotton gloves! This little machine is critical to our operation at the moment as feeds the wash plant at 25yards/h. Pretty nice as has a/c & heat. Using the new to us Hitachi EX100-1 to clear coarse tailings. Has shown a bad hydraulic oil leak through skid plates…next task! Otherwise the Isuzu engine/hydraulics have been perfect. No doubt (unless at full engine rpm) the movements seem painfully slow (lol!) That is… compared to a ‘modern’ machine.
Always lots of small stuff to repair on older units. Do the maintenance and save loss time from work. Simon C
Yes, should have realized when tilting cab for new starter that the green corrosion on (engine/starter to frame cable) was the cause of starting trouble…assumed that new heavy welding cable from battery (-) to frame would solve problem. Realize now that cable wasn’t grounded to correct spot! Thanks to all for help!
I always use a good Star washer on anything, involving batteries or charging systems. The sharper the better. Just found a Star Washer kit on Amazon, they are real SS and so sharp, they will cut you and very deep edges. Probably the best star washers I’ve ever seen. That and No-Ox.
Great advice, will check that out…
I went through the same thing on my Case 480E backhoe a while back, slow cranking on anything less than a warm day. Installed new battery, starter, cables, etc nothing helped. Found some bad corrosion on the woven copper cable from the frame to the block, cleaned and replaced, now its one of the best starting machines I own.
A bright copper coloured cable versus a greyish coloured cable is a world of difference for starting. New cables have fixed lots of 30 year old machines. Simon C
Two cold cranks now (+3c) starting better than ever has!