Backhoe B26 hydralics bypassing

[MarkV]

ok after tring out the tractor it still does not perform correctly, called the service man last week and he told me he would get with the rep. I had to go right by the shop today so I stopped in. the service manager could not tell me what my pressures were or at what pressure they bypass all he would say is that they adjusted them to 40PSI above max. I ask had he called the rep and he had not. is this adjustment done by shims or is it an adjustment.

Woody, first I would say the service manager should have easily been able to tell you what Kubota's recommended pressures are. I would hope they have a shop manual that would show them. When you use the term "bypass" it is the pressure relief valve that seems to be kicking in. My understanding is the pressure relief valves are adjusted with shims. The shims are available through Kubota. You need a pressure gauge to see what is what. Do a search on the forum. Several members have documented the process.

Kind of sorry that 2 dealer service centers as well as a company rep haven't figured it out.

MarkV

 

[woody]

Mark, thanks for the advice. the reason I ask that question was I have been reading on here and seen where other tractors were adjusted by shims but when the service man said they adjusted mine I ask him point blank with shims or an adjustment and he said the B26 was an adjustment not shims but that it is not hard to do. made me scratch my head all the way to my truck. been tring to get in touch with Marcus Hecker the Kubota Rep. but no luck
Thanks again for letting me vent.

 

[MarkV]

Well Woody I could be wrong. I have a B21 and although I have never adjusted mine, I have been told by those who have that it was shims. The B26 is a newer model and could have a different system.

MarkV

 

[wdchyd]

Well Woody I could be wrong. I have a B21 and although I have never adjusted mine, I have been told by those who have that it was shims. The B26 is a newer model and could have a different system.

MarkV

You both could be right.....depends on the manufacturer and specs given by the tractor mfg......both do exactly the same where the one with shims does not allow for tampering with......both work the same when adjusted properly......

 

[kennyd]

I believe the "shims" are used on the tractors main PRV on the transmission. They are adjusting (I would assume) the valve on the hoe, and that is probably a jamb nut type PRV.

 

[woody]

does anyone have directions and maybe pics of the prv main and hoe. the lifting on my fel is not what my other backhoe is. if I increase the pressure on it will it make a difference on the hoe.

 

[J_J]

If everything else is good, raising the pressure will increase the force. You should know the upper limit for the BH before adjusting the relief valve. You will need a gage to do this. You might have a leaking valve, or something. Is your tractor supplying the pressure and GPM's for the BH?

 

[woody]

JJ, from what the service manager said (yes). but when I asked him what the numbers were he would only tell me that they set the BH 40psi over max. I am finding some of this info hard to believe.

 

[J_J]

Does he know your tractor psi rating. By setting the BH PRV over max. What max. The main valve/fel valve will then control the relief pressure for the complete system..

Another thing, is how can you set 40 psi over unless you have the pressure to observe.

Essentially what he is referring to is that if the BH PRV is set over the over the limits of the BH, is that the FEL PRV will provide the only pressure and protection for the hyd circuit. . T

 

[woody]

Does he know your tractor psi rating. By setting the BH PRV over max. What max. The main valve/fel valve will then control the relief pressure for the complete system..

Another thing, is how can you set 40 psi over unless you have the pressure to observe.

Essentially what he is referring to is that if the BH PRV is set over the over the limits of the BH, is that the FEL PRV will provide the only pressure and protection for the hyd circuit. . T

like I said I am having trouble understanding this