loader knocks when raising and steering difficult

[Stephane395]

hello everyone,

i am new on this post, i have a john deere 3720 and just recently the loader was knocking when trying to raise it. I thought it was because of the temperature but after leting it run for 25 minutes the problem continues. I changes the side suction filter today and noticed that the filter inside had been crushed so i was sure that by replacing this part my problems would be solve. unfortunatly this is not the case ....can anyone help

 

[aginn]

I would think that you have a blockage prior to the filter. It takes a heck of a vacuum to collapse a filter.

 

[Stephane395]

I would think that you have a blockage prior to the filter. It takes a heck of a vacuum to collapse a filter.

what do you suggest...do I have to drain all the hydraulic system?

 

[aginn]

I am totally unfamiliar with your tractor, so I can't advise on that. Someone in here should be able to tell you.
My only experience with a collapsed filter was on a Cat 245 backhoe that had a bad hose that was separated inside and sucked itself into a blockage. I just don't know how your machines hydraulics are run. I truly wish I could help you more, but I am sure that someone will soon post. That's what this site is known for.

 

[cruz54982]

I agree with aginn must be a blockage,if it is as cold there as here in Wisconsin I wonder if moisture has blocked the sump screen in the oil pickup before the filter - if you can get the tractor to a heated place for long enough to warm the entire unit and then check the drain plug for water you might have the answer to your problem.

 

[aginn]

I suspected someone much wiser than I would post soon. I completely let your location go right over my head. It is and has been above freezing here, so that wasn't even in my thoughts. My money is on cruz's post.
Whatever you find that fixes the collapsing filter should cure the problems mentioned in your topic.

 

[Stephane395]

Thanks I have placeded the tractor into the garage for the night will check in the morning and see if this solves the problem, should I simplyreplace all the hydraulic fluide and change the filter at the same time?

 

[TomSeller]

What do you mean by the "inside" of the filter was crushed?
Was the outside of the filter collapsed inward?
Was it possibly hit by something?
Were the insides of the filter loose such that something may have dislodged and gone into the system?
What color was the hydraulic fluid?
Have you modified your hoses recently or detached and reattached anything?
If any quick disconnects are in the main circulation or tank line, have you made sure they are fully seated?
Could you have recently got water into the transmission?

 

[Stephane395]

On the side of the tractor there is the suction fliter inside this filter is a mesh filter that captures any particles that is what was collapsed the hydraulic fluide was good had nice color and texture to it. I have removed my log splitter in the back of the tractor and the problem was more present after this but was experiencing some of this prior to this....the tractor only has 320hrs on it has always been well maintained. I typically place a snowblower in the back in the month of dec and will use the log splitter during the summer and fall months

 

[Tx Jim]

Parts schematics shows an inline filter at the front of tractor by the hyd oil cooler.

 

[Stephane395]

Parts schematics shows an inline filter at the front of tractor by the hyd oil cooler.

THanks JIm I will look at that this morning...did not know there was a filter for the hydraulics there!

 

[445A]

i have a john deere 3720 and just recently the loader was knocking when trying to raise it.

I saw an old Deere that was knocking, turned out to be the LoveJoy, or rubber cushion between the hyd. pump and the engine, had deteriorated and the two drives were hitting on each other. Replaced the rubber cushion, as JD refers to the part, and the noise was gone. Just an idea.:confused3: I don't know anything about your filter problem, but someone else will. 445A

 

[Stephane395]

I agree with again must be a blockage,if it is as cold there as here in Wisconsin I wonder if moisture has blocked the sump screen in the oil pickup before the filter - if you can get the tractor to a heated place for long enough to warm the entire unit and then check the drain plug for water you might have the answer to your problem.

So I have placed the tractor in the heated garage all night and this morning took it out and the same thing was going on ...however I was detecting a noise coming from the back end of the tractor when the engine was turning full throttle I let it turn for a while and then started playing with the lever up and down with the loader as I did this for several minutes things started to improve until everything came back to normal. I let the machine cool down and tried it again and as it was cool it did it again but not as much. As it warmed up everything was good again.....could this have been because of air in the hydraulics and as I moved the loader up and down the air got out??? I am not sure why it seems to be ok again.

Stephane

 

[Stephane395]

it is much colder tonight ...i tried to start the tractor again and the loader goes up knocking again ( jerks up in small upward mouvements) anythoughts???

 

[DABSGT]

I am not familiar with your John Deere model but as aginn I had a backhoe, JD 410, that did the same. A collapsing line caused the problem, drove me nuts chasing after everything until a hose blew, I changed it and all was good. Best of luck, there are grater minds than mine here to help.

 

[arlen4720]

How cold is it there? I'm in Minnesota and it takes FOREVER to warm up my hydraulic fluid in the winter on my 4720. Put a piece of cardboard in front of the radiator, that will help restrict air through the hydraulic cooler. Also, make sure you are using JD Low Vis Hygard hydraulic fluid (J20D). You might need a hydraulic oil heater (which is listed in JD parts).
Of course, thoroughly check the hydraulic system for blockages.
How many hours on the tractor since the hydraulic oil was changed?

 

[aginn]

I am sorry that we didn't seem to help you much, but please give us the full story as it plays out. As you can probably tell, whatever you find may help someone in the future. It is always easier learning from the solutions others have already learned from hard won experience.
Wishing you the best on your problem. I hope it ends up being a simple cheap fix.
I still hold with my first opinion on the problem though. Somehow you have a problem that has created a blockage before that filter in the system.