Deere 310E with zero transmission hyd pressure. Pump or regulating valve?

[JL Sargent]

The orifice.

 

[JL Sargent]

My plan is to go ahead and take this control valve completely apart, clean everything, polish the bores, buy a gasket set, put it back together. What else should I do to it and
then what?

 

[mg2361]

Looks good in the pictures. If spool moves smoothly don't worry about the marks. Yes, I would install new gaskets. While you are in there make sure the screens on the ends of the solenoids are clear. Also check that the orifice (item #9 in attachment) is in place and tight. Also make sure the other spools are free as well. If all OK then you have 2 choices. Remove duct plate and inspect or remove transmission and split apart. One more question, at the moment the park brake applied from the pressure drop did you check the oil level at the same time?

 

[JL Sargent]

Remove duct plate and inspect or remove transmission and split apart.

What would you do in my spot? I did not check fluid level when the parking brake applied. Wish I had thought of that. I guess we are down to either the duct plate has a blown gasket or the pickup pipe is cracked/loose?

 

[JL Sargent]

I've been looking at it. Would you say that pulling that duct plate is at least 1/2 as much work as pulling the trans? Here is what I'm thinking. Reinstall cleaned and polished control valve with new top and bottom gaskets. The plate with its rubber gaskets on back of control valve looks fine? Test backhoe to see if I bought anything and check dipstick if/when it applies parking brake. If problem still there and fluid running up dipstick, then go ahead and pull transmission. If fluid stays stable even when brake applies, I don't know.....Then I'm back at pulling duct plate I guess.

 

[mg2361]

If the fluid is climbing the dipstick and your vent is clear, it sounds like there is severe aeration going on in there. If you have the machine in the air like we discussed before you could take the duct plate off and look at the gasket. If nothing found then continue on. I apologize that I don't have an answer for you. It can be a challenge trying to troubleshoot from a laptop without being able to see, hear and feel for one's self. I am impressed with your thought process through this whole thing. I attached 2 JD solutions about oil coming up dipstick or out the vent. It says "G" backhoe in the text of one but does apply to "E's" as well.

 

[JL Sargent]

Are you suggesting I go ahead and pull the duct plate now or go ahead with the plan I layed out in post #45? I certainly realize its not easy to figure this one out. I do appreciate all you help! I will get to the bottom of it though. Your insight has saved me a bunch of unnecessary work and has helped me to understand how this machine works.

I bought this backhoe to replace my 28 year old Ford 3910 farm tractor which I added a front end loader and a backhoe to. I plan to use it to help with the football/baseball/softball fields at my son's school which is across the street from from our house. I'm not in a big hurry to get it going. I work on chassis and shipping containers for a living and this backhoe is sitting beside my house while I work on it. A little about me: I have always been mechanical minded. I have built a couple of V6 outboards, a 5.3L Gen IV LX based GMC truck engine, scratch built a log splitter, air power forging hammer for blacksmithing, etc. I mention these things to say that I believe I can take this transmission apart and put it back together. If you have time to check on me here and offer your advice while I journey through this thing, it would be a big help. If you do not, I completely understand and wish you the best. JL Sargent.

 

[JL Sargent]

Those documents suggest that cold and before startup, the fluid level should be 5" up from the full mark. That is exactly where mine is, so I do believe I have the correct amount of fluid. I did clean my vent first thing back when I started working on this. Interestingly, I have never seen fluid come out that vent or out the dipstick tube.

Let me ask you this. If the control valve and charge pump are both working properly and the parking brake applies itself due to low pressure and there is no aeration up the dipstick tube, does that point to pretty much the duct plate gasket? What else could it be? Now if I have aeration, then doesn't that have to come from the suction side of things? That meaning charge pump feed pipe, o-ring, duct plate, gasket, o ring at charge pump?

 

[mg2361]

First, I do plan on seeing this through to the end. So with that being said I think there is something like a crack in a tube that opens up when the trans warms up. The duct plate could have a gasket partially blown causing the same issue. Cold oil you have pressure and when it warms up and the oil thins and the pressure drops. So if you have aeration, take the trans out. If not take the duct plate out as outlined in your post #45. In the end I think the trans will be pulled. Again, good job.

 

[JL Sargent]

Thank you! I have to work out of town tomorrow (Thursday), but I plan to work on this Friday. I guess I might as well go ahead and pull that duct plate friday and see what we have. The main hydraulic pump, charge pump, and duct plate will eventually come off anyway if I have to pull the trans. Might get lucky and it be that gasket, but I doubt it I wish there was a way to take a bore scope and look at that tube in the trans. I'm guessing it's ok to pull the trans with those things (duct plate, charge pump, control valve) already off it?

 

[mg2361]

In my experience with the pick up tube being cracked it was usually cracked near the top so that might be difficult getting the bore scope up there. Worth a try if you have one or know someone with one. If there is an issue with the pressure tube for the MFWD you would probably see that with the scope being that tube is near the bottom. Yes you can pull the trans with that stuff removed. I'll be leaving for vacation Saturday so I will be unavailable for a week. I'll check back with you when I get back to see how you made out. Hopefully with the problem solved!!

 

[JL Sargent]

We got a big rain last night and it dumped 1.5" of water here. This made working on the backhoe tough and I spent a couple of hours just drying and cleaning tools. I did manage to drain the hydraulic tank and disconnect the hydraulic pump. I've gone through the control valve and have it mostly put back together, waiting on that bottom gasket from Deere. I did go to the Deere dealership and talked to the service writer. I mentioned what the backhoe was doing and he said that even a clogged pickup screen could cause the problem I'm having. He said there was a baffle in the transmission that can come loose and that is what rubs a hole the tube sometimes.

I plan to continue tomorrow pulling the charge pump and the duct plate to have a look/see. Barring some great discovery with that, I will continue to work towards pulling the transmission. MG, I hope you have a great vacation week! Yes, hopefully when you get back I will at least have the trans apart and on my way to repairing it. I'll post pictures of whatever I find.

 

[mg2361]

Thanks. Yes there is a baffle around the MFWD clutch pack. The pick up can been seen through the drain plug. More likely maybe something floating around (like a piece of the baffle?) because you said you shut it off and restart and have pressure, like something falls off the pick up and then reattaches. See you in a week.

 

[JL Sargent]

I've removed the duct plate and the gasket is pictured. There is a small piece missing where the charge pump mounts, but I did that removing the plate. I don't really see any tears or other damage to it. Time to pull the trans.

 

[JL Sargent]

Wow, a picture is worth a thousand words. I used a bore scope inspection camera and looked down the charge pump feed pipe. Look at the pickup screen! Is there some way to clean/flush this out without tearing down the transmission?

 

[JL Sargent]

Also, the transmission is drained in these shots. There is still fluid pooled in the bottom of the screen! I can only imagine what the OUTSIDE of this screen looks like. That kinda looks like some kinda growth?

 

[JL Sargent]

Here is another one.

 

[JL Sargent]

Tomorrow I'm gonna try to clean that sludge from the pump end of that tube with diesel fuel and a air gun/pump/something. I plan to catch everything from the drain hole in a paint filter to see if I'm making progress. After a while I'll rescope it and we'll see. Might get out of pulling the trans yet!

 

[JL Sargent]

So after two hours of back flushing charge pump feed pipe with diesel and air power I have this.

 

[Tags]

What the hell is that?? Some sort of algae?? Looks like you did a great job cleaning it out, whatever it is....