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WA320-3 transmission problems

DMC

Active Member
Joined
Aug 21, 2006
Messages
28
Location
QC
Been having a problem with my loaders transmission overheating and sometimes not wanting to move.
Sometime the loader will start and go in gear just fine. Sometime after starting the loader and putting it in forward or reverse it wont move. I have to rev the motor and it will move slowly, then it will suddenly start moving fine. I changed all the solenoids thinking they weren't working properly, still the same. I changed the relays around and sometime that will work to get it to move. Sometime if I tap on the relays it will go in gear and move.
But after all of this the transmission will run hot after being used for a little while. Changed the filters, oil, still the same.
Any ideas. Only thing I can maybe think of its the troque converter pump??
 

funwithfuel

Senior Member
Joined
Mar 7, 2017
Messages
5,518
Location
Will county Illinois
Occupation
Mechanic
Did you put a gauge on it, have you checked for a sump strainer? Are you using recommended lubricant?

Any error codes associated with the failure?
 

DMC

Active Member
Joined
Aug 21, 2006
Messages
28
Location
QC
I haven't tried a gauge yet, I have oil flowing through the cooler but I will check the pressure with a gauge. This is a 1996 model and I can only find 3 filters and strainers. I've changed them all a couple of times. At one time when I changed the filters, the little pilot strainer was crushed. I'm assuming from the pressure. I'm using the correct oil and there also I've changed a couple of times.
Another thing that happens is sometimes when I push the brake the parking brake locks on for a couple of seconds. Very dangerous when traveling. Could a ground or bad wiring be the cause of these problems?
 

DMC

Active Member
Joined
Aug 21, 2006
Messages
28
Location
QC
I'll check that and get back. Thanks, now I'm remembering that when traveling and if I push the brakes to slow down, loader take a long time to get back up to speed. I'll check the brakes. Thanks again.
 

max s

Active Member
Joined
Oct 2, 2012
Messages
36
Location
Canada
The issue with the parking brake engaging a couple seconds is due to the brake accumulators or the pressure sensors on it. When the accumulators don't hold pressure and you apply the brakes, the drop in pressure in the brake circuit is sense as a malfonction by the pressure sensor and it apply the parking brake. I would start by checking the acc. charge pressure. There is 2 of them, one for the front and one for the rear brake circuit.
 

DMC

Active Member
Joined
Aug 21, 2006
Messages
28
Location
QC
Didn't have time to check much today, but I did start it to move it..Started,waited until the brake pressure built and alarm went off. Put it in forward..nothing, reverse..nothing. 1st 2nd 3rd and 4th in forward or reverse.. nothing. Put in 1st forward and revved the motor full speed,after a couple of seconds the loader slowly started to move. Then all of a sudden it would move in all gears forward and in reverse. This is what happens 90% of the time when I go to use the loader. I parked it again, but I'm sure if I continued the transmission would have gotten hot. Is there a chance ALL of these problem could be caused by the torque pump?
 

John C.

Senior Member
Joined
Jun 11, 2007
Messages
12,865
Location
Northwest
Occupation
Machinery & Equipment Appraiser
Yes. I would suggest checking the suction piping for loose clamps and leaks. Seen plenty of Komatsu loaders suck air into the pumps. If that checks out you will need to check pressures to narrow down the problems.
 

DK88

Senior Member
Joined
Jan 19, 2011
Messages
320
Location
Ontario
Occupation
Field service tech.
and make sure the inching pedal isnt hanging up. and machine is free rolling.
if the filter was crushed you may want to put a gauge, typically that shows that pump failure is occuring and since the metal cant pass it plugs and crushes the filter untill a hole occurs then oil will flow and usually wash housing clean after a while.
 
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