3340 Hydraulic issue after some use

[saviez]

Hello everyone, I've been following all the hydraulic issues that everyone has posted and so far have not found a similar one I have. I have a small backhoe attachment connected to the remotes and have been using this for a few years with great results. During my last job (septic system) a problem developed where I could no longer lift the boom and you could actually hear the hydraulic system straining, which to me would indicate some restriction. I turned off the hydraulics to ensure that the remote connections were properly engaged (which they were), and then I found that when the hydraulics were re-engaged, the the backhoe operated great for about 5 minutes and then the problem reappeared. I have a front loader bucket that doesn't seem to be affected by this at all, but it seems that the rear lift cylinder is affected. I have the side mounted hydraulic pump (LH side of engine) and cleaned out the screen, however the manual also says that there is also a "paper filter" in the return line at the RH side of the tractor however I can't find this. Is there anything else that I'm missing that could possibly be restricting the flow? Thinking that it might be the couplers, I reversed the connections and the flow and still had the same problem.

 

[ixer0]

Hi,

Sounds like a pump issue when it gets hot, but you must put a pressure gauge on the couplings before you go buying a new pump.

Mike

 

[saviez]

I was thinking the same but I have a front end loader attachment which I believe is run off the same hydraulic system, which works fine consistently. Any rear implements will lift high with the oil cold but it seems that once the hydraulic system gets hot, I can barely lift any implement off the ground. Can the pressure be checked using a gauge attached to a remote coupler and what should the reading be? Thanks in advance!

 

[r77]

Hi
I know very little about these small Zetors, but yes, you should put a gauge on the hydraulic outlets and test for pressure, heaten up the hydraulic oil by doing some work with the tractor hydraulics and test again when warm, as you seem to have the problem when the oil gets hot.
Someone will come along who knows these tractors and advise.
Am actually going to look at a 3320 which is why I logged in to ask a few questions.

Best wishes, j

 

[saviez]

Just managed finally to check the pressure in the remotes. When the oil is cold cold I'm getting 2000psi and after about 5-10 minutes the pressure drops to 1000 and fluctuates between 1000 and 750psi. The the weird part is that the front loader is working fine which would point to something else other than the pump? Relief valve maybe?