Rebuilding Valve body

jjbenson · Mar 21, 2016

Hey everyone-
I have a Kubota 3400 with a BH75 backhoe attachment. Two of the valves started to stick, and slowly leak fluid out the top. I unhooked the valve body from the hoses and took it into the local hydraulic shop, which has rebuild pumps and made new house for me in the past. They won't even look at it, and said its not repairable. Kubota sells a new valve body for 2500.00 (ouch), or they sell individual valves(apparently there are 6 valves in my valve body) for a mere 750 a piece. Im just curious why the valve body can't be rebuilt? I remember taking some classes on hydraulics in college, and it didn't seem to be all that complicated. Maybe I am wrong? Is this something I can try to tackle or is it a lost cause? any ideas?

Tractor Seabee · Mar 22, 2016

This is one area where the manufacturers have a Gotcha on selling parts. Your Hyd guy is probably right as Kubota wants to sell the whole replacement, not pieces. Or Kubota may only sell the pieces to there dealer shops. In retrospect I looked in my BX parts manual and they do list individual parts for the FEL valve. The BH is a separate list I do not have. Check with your dealer parts guy.

Surplus Center has a Prince SV Back Hoe combo valve for $734.00. It is a 12 GPM capacity valve. Probably have to reroute some lines/hoses and change some fittings to adapt it.

Ron

2458n · Mar 22, 2016

Time to find a real hydraulic shop. Kubota is to lazy to invent their own seals- just the same as they do not invent their own bolts. The valves use common off the shelf seals. Someone just has to take the time to identify them. For 2500.00 dollars you are going to be able to find a shop to do it. My Kubota loader is at least 34 years old and the parts are listed as obsolete. My dealer ordered them and a week later I had everything that I needed. My Dump truck is a 20 year old 7.3 and the valve body lived underneath it exposed to road salt half the time. Cut it off the frame and it got rebuilt. Time to find a new dealer who can do more then bolt a 2500 piece on and bill you 3000.

tvman · Mar 22, 2016

jjbenson said:
Hey everyone-
I have a Kubota 3400 with a BH75 backhoe attachment. Two of the valves started to stick, and slowly leak fluid out the top. I unhooked the valve body from the hoses and took it into the local hydraulic shop, which has rebuild pumps and made new house for me in the past. They won't even look at it, and said its not repairable. Kubota sells a new valve body for 2500.00 (ouch), or they sell individual valves(apparently there are 6 valves in my valve body) for a mere 750 a piece. Im just curious why the valve body can't be rebuilt? I remember taking some classes on hydraulics in college, and it didn't seem to be all that complicated. Maybe I am wrong? Is this something I can try to tackle or is it a lost cause? any ideas?

You're going through the same thing I did. Mine is a BH90 though. It takes 2 o-rings and 2 wipers per valve.The Kubota numbers for the o-rings is 04816-00120 the wipers are RB401-70510. The o-rings are pretty cheap but I think the wipers were about 20 bucks each. My hydraulic shop had no cross reference for my valve either

My suggestion is have your Kubota dealer pull up the exploded view of your valve and then price out the parts. I just went ahead and bought the complete valve assy from Kubota for about 2k. Also, while you're in there, replace the o-rings for the hoses you disconnected.

CJONE · Mar 24, 2016

My problem with Kubota Is the dealer I have to use for parts. I have had so much problems with them that I also turn down quite a bit of work. Get a breakdown of the valve from the valve MFG or Kubota. If the spools are not pitted replace the seals and spring return kits if needed. Chances are the seals are getting hard either from age or heating. CJ

aczlan · Mar 24, 2016

Go right on the Kubota site, click on parts and enter your backhoe model number. That will get you the same parts breakdown as your dealer has.
Then you can use the part numbers to look for parts online (might try Messicks) and bypass your dealer altogether.

Aaron Z

jjbenson · Mar 27, 2016

Thanks for the information 2458n. The hydraulic shop I go to seems legit in my opinion. they have done good work on pumps for me in the past. I guess the issue is that you can't get individual seals, etc from Kubota. According to my Dad, Kubota can show you seals on a schematic, but you can't order them individually, and Kubota doesn't make a rebuild kit. If i understand you correctly, I should be able to take the whole valve body apart, ID the bad seals, and then take them to my hydraulic shop to have them ID'd, and order them? This makes sense to me, but it seems the hydraulic shop should be able to do this themselves, which i assume is why you stated i need to find a new shop. Only 2 of the valves are sticking/leaking, and it sounds like you rebuilt yours no problem. What would cause me to need to order a whole valve assembly? scoring on the walls of the valve? is that something i can actually see? or is this where i need to find a real hydraulic shop?

jjbenson · Mar 27, 2016

OK, it sounds like from all the responses that its not going to be that difficult. Get a schematic, ID the bad seals, and replace. If scoring is an issue, can it be repaired? or does this mean i need replace the whole valve piece(there are six valves). Does anyone have any tips as far as doing this work? Any help/cheats/tips would be appreciated.