Hydraulic system problem

sfg

New member

Equipment
M 4030 SU
Oct 2, 2016
12
0
0
Boaz, Alabama
I need help ! I have a 1990 m 4030 su . I was bush hogging this weekend after about an hour my power steering stopped working then I noticed my loader which was up wouldn't work either. I checked hydro fluid it was low .. No obvious leak so I added fluid everything worked but I knew something had to be wrong because I had not added any fluid to the power steering resvouir. After running a few minutes hydro fluid started leaking from the overflow on the power steering resviour . I don't know how this power steering system works Im guessing its a bad seal in the hydro pump or somewhere allowing fluid to be forced into the power steering system. I don't really know where to start .. Its been less than a year since the hydraulic system has be serviced and everything worked great until Saturday.
 

North Idaho Wolfman

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Staff member
Lifetime Member

Equipment
L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
Jun 9, 2013
28,294
4,853
113
Sandpoint, ID
You have an issue with the pump, most likely it blew a seal between the two parts of the pump.
 

sfg

New member

Equipment
M 4030 SU
Oct 2, 2016
12
0
0
Boaz, Alabama
I'm not having much luck finding info about this hydraulic system . I have a few questions that I'm sure someone on here will be able to answer . is the external pump the only pump ? Could this problem be the o rings in the hose connections going to the power steering tank ? Would rebuilding the pump be a good fix or is replacing it the best option ? And where is a good place to get a rebuild kit or a pump if necessary?

Thanks for any advice....
 

100 td

Active member

Equipment
B21TLB (B21, TL421 & BT751) Toyota SDK4 T116 Bobcat
Aug 29, 2015
1,776
8
38
ɹǝpunuʍop
Have a look here for exploded parts lists/diagrams of your machine,
http://www.kubota.com/part/partsList.aspx,
as NIW suggests, probably something wrong in the pump itself causing high pressure fluid from the main hydraulics to bleed into the steering section as these have a dual pump, I expect removal of the pump and rebuild by a reputable company in your area.
A workshop manual for your machine would have hydraulic flow diagrams etc in it.
 

North Idaho Wolfman

Moderator
Staff member
Lifetime Member

Equipment
L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
Jun 9, 2013
28,294
4,853
113
Sandpoint, ID
Is the external pump the only pump ? Could this problem be the o rings in the hose connections going to the power steering tank ? Would rebuilding the pump be a good fix or is replacing it the best option ? And where is a good place to get a rebuild kit or a pump if necessary?

Thanks for any advice....
Yes the external pump is the only Hydraulic pump.
Very unlikely that it's an O ring on a hose issue.
A pump re-builder can tell you is the pump is rebuild-able or if it is better to get a new one.
That pump P/N 35430-82202 is $850+ and may or may not be available.