Backhoe L3200 and backhoe capacity/power and operating temperature

[1savoy]

Well I had a chance this morning to check on my BH77. I first checked the tractor pressure relief. Was at 2300 PSI. This is not the problem. The BH boom would not even budge the tractor. With the bucket on the ground and curl the bucket out, the boom cylinder would just be pushed back in. Not being positive, need to get a service manual, where the pressure relief was for the boom circuit, I called the dealer and spoke to a nice gentleman. He said they have run into this and just pull the relief out and put it back in and the problem was fixed. I noticed Kubota used teflon tape on all the fittings, even though I was always told this is a no-no on hydraulics. Double checked with him where the relief was. Pull the shroud off where the control levers are and pulled the hydraulic relief (cushion possibly) valve. Did not find any debris. Pulled the valve apart just for fun. Need a 22mm and 24mm wrench or socket. No debris still, but put it back together and works like a champ :cool2::cool2: BH picks the tractor up very easily at an idle now, and the rears are loaded. Called the dealer back and thanked them. Decided to pull the dipper relief/ cushion valve also just to be safe. Gotta love the easy fixes. When I used the BH before to dig out a stump, I found I could not pick the stump up with the BH extended. The boom would just sink back down. Now with the boom and dipper fully extended, the BH picked up the tractor easily. Just thought I would pass along my findings. Whole process should only take 15 to 20 minutes. I attached a couple pictures. Boom stack valve is second from the right. Dipper is second from the left.

 

[JoeBuyer]

Very good news. Did the dealer say why the valve was apparently sticking open or did he say that it might happen again? Maybe the valve was not lubed correctly in manufacturing and it was initially "stuck"?

 

[1savoy]

Dealer did not say why the valve would stick. I think our assumption is debris. I did not find any debris, but my thoughts are that possibly all the time between being built, shipped, sitting on dealers lot, etc, just caused it to stick/ hang up. The relief valve has hydraulic fluid in it, so lubed correctly, I would think should not be a problem. I would think now that it is working, it will stay working, unless it sits for an extended time. I guess time will tell and be curious how the original poster makes out with the same/ similar problem.

 

[petroliapete]

1savoy
thanks great information. i talked to my service manager. He thinks it doesn't sound right either. I am goingto have it dropped it dropped off (although part of me wants to dive and do it myself)..Thanks for the info. Do you mind if I pass on your notes to my service manager? Too many projects before winter. Good news though - brushog is AWESOME

 

[1savoy]

petroliapete,

Glad to hear your dealer is going to take care of yours. Feel free to pass along the info from my dealer and my findings. I hear you about wanting to dive in yourself, I am the same way. I bought this Kubota long distance, so I don't really have the ability to have the dealer pick it up, but I knew that going in. I enjoy working on stuff myself and keep my fingers crossed I never have any major repairs needed under warranty. Keep us posted on what the dealer finds with yours. Did you ever get a chance to check the temperature of the cylinders?

 

[bumperm]

This thread is getting long in the tooth, though still some unanswered questions . . .

B3350 with BH77 hoe, so the BH is a bit more than a foot further aft due to a frame mount spacer to allow the BH seat to fit behind the tractor cab. Haven't noticed any lack of digging power, but the hydraulics "sound" like there is a bypass going on any time force is exerted by hoe. Like others have noted, cylinders get quite hot. I'll check them with a IR temp gun next time I use hoe.

Any follow up info appreciated

 

[1savoy]

Hi bumperm, Sorry I do not get on here much anymore, so just seeing this. I don't remember having the bypass sound at all when using the BH. Seems like you hear some hydraulic fluid type noise, but not the bypass. Seems like I may have had this type of thing happen once and it was the return hose was not fully seated. I would pull both hoses going to the backhoe, at the quick dis-connects, and check condition and for debris. Then reconnect and make sure they are fully seated. Hope that helps.