Hi Guys. waz wondering how you check continuity on a 8 pin plug that runs into the control valves on my wa380-1 tranny.two of the wires have 24volts running through them,the others i have to check for continuity,to elinmate if it is a wiring problem or solinoid or god forbit mechcanical problem.
If this control works through an ecm a broken wire or shorted solonoid coil should produce a fault code. I would remove solonoid stem and make sure the spool is moving when powered up( disconnected from ecm of course). Other wise just use a volt meter to check cont. If you have multiple solonoid you can check resistance on all the coils and see if any are out of range.
checked continuity today all good to the plug into the control valves. manually operatered the spools to eliminate if it is a electrical problem or mechanical, to my relief it seems to be electrical as the machine move freely when the spools were ingauged manually. checked voltage to the solonids and got beteewn 20-24 volts to each one (6).noticed the solinoid would get hot when selected would think that is normal, will check resistance on the solinoids tomowwo,they should be around 60 nomes.
That depends on what you call hot. They will sometimes get a little warm but hot usually means a shorted solenoid. I have a tool that works like a test light but for testing solenoids. It picks up the magnetism and lights up when they are working. If I get out today I will get the manufacturer and part number off of it. This thing has sure saved me a lot of time on tracking problems like this before.
rechecked voltage to solinoids,getting correct voltage to the selected solinoid but when i checked the other solinoids that wasnt selected some were getting voltage????? should i be getting any voltage to a solinoid which is not selected,the voltage reading on one was 16volts.
It was common on the earlier loaders for the harness that goes into the transmission to cross short between leads inside the harness. What happens is you get voltage on three solenoids at once and that locks the transmission. The issue might jump to different packs as you run the machine and sometimes work properly. The other possibility as I recall was that there were a bunch of diodes connected to that harness and installed in the cab harness above that one. You will need to check all those diodes to make sure they are OK. At any rate the cure is to replace that harness. Another issue with them was that there were several different harnesses depending on serial number. Don't order the new harness until you get the old one out. There should be a part number tag on the harness. Order the new one by that part number. Sometimes the tag is gone or unreadable. Order the new one by serial number and don't accept it until you check the new harness against the old one to make sure all the plugs are the same and all the right colored wires are going into the same plugs. Good Luck!
John C you are a legend that is exactly what the transmission has been doing as far as the transmission locking up,i take it you are talking about the 8 pin male plug that runs inside the the control valve block,is it hard to remove as i am abit limited for room. also iam getting different resistence reading on the solinoids.iam not shaw if i have the right setting on the multimetre.Can i use the continuity setting to get a rough idea.
As I recall a bad solenoid will either have no resistance or infinite resistance. You can check a number of used solenoids and they will all read a little different. The book used to give a range that was pretty large. I don't have access to any loader books anymore so can't help you that way. I never used a continuity tester before so don't know what to tell you on that subject. I always used a multimeter on ohms to check diodes.
Pulled out wiring harness that goes into control block today,was a fair bit of rust around the back of the plug,pulled coils off the solinoids found the same alot of rust around the coils,looks like they silastic the valve cover on but moisture has got in threre over time.thinking about removing control valve block off and checking out solinoids since i have come this far.
solinoids pic of the surface rust on solinoids any ideas on the best way to clean them up?
Fine emery cloth with a bit of light oil should do the trick.
cheers nige, will be replacing 3 of them as they have no resistance,and the others as you can see have abit of surface rust on them. Bloody Komastsu dont miss ya $340.00+gst for each solinoid and $400.00+gst for the wiring harness so far.
If you're certain that you know it's the solenoid part that's defective and not the valve itself is there any way you can buy just the solenoid itself rather than the complete valve assembly..? I have no idea if Komatsu sells them like that, but I know Cat generally do so it's worth an ask to Komatsu at the very least. If you try moving solenoids around on valves you ought to be able to diagnose if all your valves are actually working correctly.
nar good old komastsu only sell the coil with the soliniod as that was the first thing i asked,if a coil has no resistance is there a chance the solinoid would still work?.
The coil can be bad while the stem is still operational. To bad you had to buy it all.
What you need is the diameter of the stem, height of the coil and any locator pins that may be on the bottom of the coil. I used to buy just the coils for other machines from Spencer Aircraft years ago. They supplied lots of hydraulic parts back then. Maybe they still do. Good Luck!
If there is no resistance in the coil the solenoid will not work. It will just blow a fuse of trip a circuit breaker.
Out with the old in with the new
It's all very well putting new parts in there, but does it work now ........??
Nige, Took it for a test run down the road,all good smooth changes up and down through all the gears,it seems to be getting more power through the tranny when you are digging into a stockpile probably due to one gear selected rather than proir when there was getting voltage to serveral gears at the one timeeee.