Hi there, I am new to this forum, and after looking thru 43 pages of Wheel Loader topics I have not noticed a single inquiry regarding this particular machine. The machine Ser No plate starts the confusion by showing it as RA501, yet the decals on the rear mudguards say RA601. Machine is a Hydrostatic drive, with a 2 speed transmission, it uses a Kubota 1503 3cyl turbocharged engine, into a Pump Assembly consisting of a Uchida-Rexroth Travel Pump, which drives the Uchida-Rexroth Travel/Drive Motor, the main travel pump also couples to the main hyd pump, for the loader hyd's & steering, with the Travel pumps charge pump on the end. Am trying to get the transmission electrics sorted. Currently I am unable to get the original F-N-R switch on the left of the steering column to work. As this is what they call a "Grey Import" into Australia, i.e not imported by the offical Kubota people, I seem to getting a lack of back-up/assistance from Kubota Australia. I would like to be able to get a copy of the wiring diagram, or even look at purchasing a Workshop Manual. These machines may have been only available in Japan, as all Serial Number Plate and Fuse Box are all in Japanese writing, it makes it hard to even work out what fuse is for what. I have managed to move the machine from the pit where it was working by applying power to the solenoids on the Travel Pump after working out the terminals on the solenoids, and have temporarily hooked up a ON-OFF-ON switch to operate the transmission. I am also looking to procure parts for this machine, need coupling rubbers and bolts, for the pump drive coupling. Since moving the machine it has now come to a halt, as the pump drive coupling bolts have failed through serious wear to the bolts which has caused them to fail, as they had been 12mm bolts, but had worn down to about 3.5mm-4mm. Now have the job of removing 3 broken off bolts which I think have been installed with "Loctite" in the flywheel. If there is anyone out there who can assist with info on supplier of parts, or manual, it would be greatly appreciated. These "Grey Imports" are great when they are going, but a pain in the butt when they break.
Unable to find/locate the edit button so will add pictures in an additional/reply post. Someone maybe be able to see a similarity to a machine available in their area. Cheers Waz
It looks just like the US R420Sand the R520S machines.
Looks like my criticism of lack of Australian support may have been a bit premature, although this still applies to Kubota Australia, as they did not offer to follow up on any parts I wanted to order. However our local (Brisbane) Kubota Dealer just happened to have a RA501-RA601 Parts Book albeit with Japanese descriptions, and after liasing with thier Parts Department, we have been able to check the price and availabilty of all parts required, appears most of the parts are available, and are in stock in Australia. However since removing the Hyd Pump assembly from the engine, we have found the splines on the pump input shaft, and its mating splines in the drive coupling are U/S, plus when the coupling bolts failed they were carried around inside the flywheel housing until they got caught between the flywheel and the housing, resulting in a cracked flywheel housing and a small hole where it "spat" out the bolts. Looks like the Flywheel Housing and a new pump will have to come from Japan. I have checked with Rexroth in Brisbane but have been advised that they do not import this particular pump into Australia, and at this stage it appears I will not be able to get replacement parts for the pump, just a complete new pump assembly for AUD$7305.44 from Kubota. We are weighing up our options, and looking at the different ways to get the machine going again. Regards Waz
Im not sure how, but if someone has a parts book for an R420/R520 in the US maybe you could cross the part #s and price it out elsewhere? $7000 is an awful lot for a pump and depending on the hours of your machine would it it be worth the cost to repair?
I'm still waiting on clarification of what I get for my $7k, the picture in the parts book shows all 3 pumps as an assembly, with only one tag to a part number R1401-96102, I suspect for this amount of money that it will come as a group of 3 pumps. Machine has 8071hrs showing on the tacho, but this was not working when I first looked at the machine, found the outer sheath was undone on the engine end, after I screwed this back on I noticed the Hour Meter was working, but the tacho didn't work, I don't know how long the hr mtr hasn't been working, but by the wear on the splines of the pump shaft, I would say this is pretty well correct, if all the parts are original. I have been in the earthmoving repair game since 1969, and it just bugs me that I can't go down the road and get a replacement shaft, a seal kit, and replace the damaged shaft. All the pumps, both the Travel Pump and the Main Hyd Pump, all appear to be giving plenty of output, so one can only assume, (there's that word again), that the charge pump (the 3rd pump in the group) on the end which feeds the Travel Pump is OK also. Waz
$7000 is rediculous to spend on that. I am sure you can buy just the shaft. Have you tried a hydraulics repair shop? If it were mine I would epoxy the splines and slide it on. It would last what is left on the machine
I don't think the epoxy route would work, as the Drive Coupling has to be mounted on the Flywheel, then the Flywheel Housing fitted, then the pump is refitted and bolted to the Flywheel Housing. Have got confirmation that $7300.00 only buys me the Travel Pump, but it is avail in Melbourne, Australia. Unfortunately I have only checked so far with Rexroth who manufacture the Pump, and as I said in a previous post, they do not import this particular pump into Australia, they doubt I would find any Hyd Shop with a shaft to suit. I am hoping to try to get a better result with the Rexroth people, to see if the main shaft is used in other types of pumps, of the same base model, which are readily available in Australia, I would like to think that all the base models of this pump would share the same main shaft, with just the control mechanisms being the main difference. I just have to try to get this info from Rexroth. I have tried to "Google" the base model number A4VG28 (A4VG28DA-959-3) but can only come up with basic pump rebuild kits, (Mainshaft, Piston Assembly, Barrel), for a substantial amount from Chinese manufacturer's wanting to supply multiple kits, with min qty's of more than one. My other option is to see if I can find a local Engineering Company to manufacture one. Waz