350 Hydraulic leak

[Granddad]

I started the 350 for the first time this winter last Monday. It didn't want to start, had an old dead battery. Replaced it with one from the fifth-wheel camper, which was low also. After using the charger on the starting circuit it still didn't want to start so I disengaged the hydraulic pump from the system and she fired right up. Let it warm up for 5-10 min and moved the lever back to engage the hydraulic pump again. Used the dozer to clear out a few persimmon trees from the overgrown hayfield and put it in the shop. When I walked away from it setting on the concrete floor I could see that I had a hydraulic leak at the front close to where the hydraulic pump is.

I did not crawl under it to look more closely(recovering from back surgery in Dec.) I could see the drips falling. I was surprised the the hyd pump cut-out lever was so hard to move. I had to use a cheater pipe to get enough leverage to move it forward, and then it took a lot of pressure. It even required help to move it back to the rear after the engine had warmed up.

What am I likely looking at here? It might be something as simple as a loose connection on a hyd line at the pump. But since I've had no leaks prior to moving the cut-out lever I am thinking it's probably not a simple line leak. In looking at the shop manual I don't see anything in the lever linkage that should cause a leak simply by moving the lever.

Is there a hydraulic reservoir someplace under the dozer or is the one in the right armrest area the only one?

Is it likely that simply exercising the lever forward and backward a few times might clear things up? Am I missing something here? I have little experience with dozers, having gotten this late last spring. I would sure appreciate any comments and advice on this.

Now for the reason that I started it in the first place. I wanted to move it inside so I rebuild/rebush the 6-way blade control handle. I have the necessary roll pins, bushings etc. Is this a pretty straight forward job, taking it apart as I go and then reassembling with the new parts? Is there anything I should know about before I get into it? Again, I will appreciate your advice.

Granddad

[Lavoy]

Shifting the drive lever really should have no effect as far as a hyd leak, it may just be coincidental.
There is a bushing that the TEE handle goes through, you will want that as well, and there might be a plastic thrust washer in there as well, or at least should be. Check all of the pivot holes, you may find that some of them are wobbled out and your roll pins will not fit tight. Then it gets a little tougher. I have welded them all shut and re-drilled, but that is a pain too. Not sure if JB Weld or something like that would hold in the long haul.
Lavoy

[jdemaris]

After using the charger on the starting circuit it still didn't want to start so I disengaged the hydraulic pump from the system and she fired right up.

I could see that I had a hydraulic leak at the front close to where the hydraulic pump is.


Is there a hydraulic reservoir someplace under the dozer or is the one in the right armrest area the only one?


Is this a pretty straight forward job, taking it apart as I go and then reassembling with the new parts? Is there anything I should know about before I get into it? Again, I will appreciate your advice.

Granddad

As Lavoy said, the lever and disconnect don't have any effect on parts that can leak oil - except when you force the lever it puts thrust pressure on the hydraulic pump shaft. If the pump was already worn, forcing that disconnect might have been the "straw that broke the camels back" and created a leak at the shaft-seal.

Those disconnects usually don't work at all, and we eliminated them from many Deere crawlers. For the most part, they caused more problems than benefits.

If your pump is leaking via the front shaft - you're money ahead to just replace it with a new pump - rather than attempt repair. It's a Cessna pump made of pot-metal. When the shafts and steel bushings get wear - and the gears can side-thrust when pressures get high, the front seal will blow out. There IS no fix. Years ago, Cessna let Deere sell repair parts, but they were discontinued late 70s- early 80s. Seal kit is still available, but not shafts, bushings, or center-housings. You can buy a brand new pump for less then $200 if you shop around. OEM is 13 GPM unless you machine has aux. hydraulics - and they it'd have a 23 GMP pump.
(there are a few crawlers around with cast-iron Webster-Electric pumps - but they are rare).

I'm kind of wondering why disconnecting that pump made a big difference in cranking speed. It shouldn't have. That crawler has an open-center hydraulic system - and if you have the correct weight oil - and none of the hydraulic filters are plugged - it should crank pretty much same - connected or disconnected - even if it's 20F below zero.

In regard to the bunch of iron snakes in that 6-way control. The last thing I'd call it is "straight forward." I had to repair many out in the field - and it's a maze. For the price of the kit, you're often better off just repairing the old parts - filling holes and drilling, or drilling and using oversize pins, or drilling and installing bushings.

[Granddad]

I think I have all of the roll pins, bushing, c clip etc. I don't recall what else I have. These parts are down at the shop. As far as being wallered out I wonder if JB Weld around the outside of the new bushing would hold it in place. This unit doesn't get much use, or at least hasn't yet.

If the cutout lever is just an L shaped lever as the diagram in the service manual shows I can't see why it shouldn't move forward and backward easily. I hope I didn't do any damage to it. We are supposed to have decent weather next week so I hope get to spend some time on it and see just what the situation is. Hopefully I just have a loose connection.

If I do need a new pump, where would you suggest I begin looking for one? I presume that the $200.00 you suggested is for a used pump.

Another unrelated question. I see pictures of some 350s that the hood fits closely to the radiator cowling on the front and on the support at the rear. Mine has an inch gap at the radiator cowling and about a half-inch gap at the rear. I know the units had a John Deere yellow dealer engine rebuild about 160 hours ago. Is it likely it wasn't put back together with the appropriate care, or is it likely that the hood is off a 1010 or a 2010?

Thank you

[Granddad]

Another point. When I tried starting it after moving the cutout lever forward it didn't seem to turn over that much faster. I thought at the time, "Well that didn't do much good", but all of a sudden it started. Sorry if I gave the impression that the engine turned over a lot faster after moving the lever forward.

[jdemaris]

I think I have all of the roll pins, bushing, c clip etc.

If the cutout lever is just an L shaped lever as the diagram in the service manual shows I can't see why it shouldn't move forward and backward easily.

There are many parts in there to seize or fall apart - much more than one lever. We had many problems with them,and usually just elimated the whole mess and just installed a shaft and couplers instead. Deere later elimiated the whole mess anyway.

If I do need a new pump, where would you suggest I begin looking for one? I presume that the $200.00 you suggested is for a used pump.

$200 is new price - buying a used pump is usually a waste of time and money. Those pumps are a standard configuration and also used by IH, Ford, AC, Case, etc. Very easy to find surplus. Standard shaft splines and standard SAE mounting. Standard dozer pump has a smaller shaft than a option larger pump - or loader pump. The small one is 13 GPM and larger one is 23 GPM. My memory is a little foggy, but I think the small standard dozer pump has a 3/4" splined shaft, and the larger optional dozer or standard loader pump is 7/8". These pumps sell all over and availability changes all the time. It's best to buy when you see one cheap - and NOT wait until you must have it. I've bought many 13 GPM dozer pumps new for less than $150.

Anything over a 1 c.f. pump will work. Just make sure you match SAE mount, rotation, and shaft-size and spline count.
Here is one with the larger shaft for $287 new - 7/8-13 tooth spline

http://www.surpluscenter.com/item.asp?U ... =hydraulic

Another for $169 new:

http://www.surpluscenter.com/item.asp?U ... =hydraulic

$187:

http://www.surpluscenter.com/item.asp?U ... =hydraulic

I see pictures of some 350s that the hood fits closely to the radiator cowling on the front and on the support at the rear. Mine has an inch gap at the radiator cowling and about a half-inch gap at the rear.
Is it likely it wasn't put back together with the appropriate care, or is it likely that the hood is off a 1010 or a 2010? /quote]

1010/2010 hood is quite different. I suspect your nose-cone up front, and/or the engine-cowling is out of adjustment. Both will swing towards the engine - or away from the engine when the mounting bolts are loosened. If both are too far from the hood, just loosen and pull them in.

[Granddad]

I had chance to play with the 350 today, temps in the low to mid 60s. Couldn't find a possible leak until I started it up. While I couldn't pinpoint the leak for sure, I did find hyd oil dripping from a hose clamp on the left side nest to a radiator hose. I can't be sure if that is the origin of the leak or if it is just collecting there. It is close in to the nose cone, so I can't see yet if that is the origin or not.

The nose cone has a heavy strap on each side toward the bottom. If the front bolt on each side is loosened can the nose cone/grill housing be tilted forward without having to take it clear off? If necessary I can go in with a flex shaft tool and tighten it, but it would be much better to see what I'm doing and have room to do it. Oh yes, this is all right next to the fan blade at about screw driver handle height.

[jdemaris]

If the front bolt on each side is loosened can the nose cone/grill housing be tilted forward without having to take it clear off? .

Yes, it is made to swing forward without being removed. You have to make sure you take out the bolts underneath where it is attached to the belly-pan.

[Granddad]

Update on the hydraulic leak. It turned out to be in the power steering circuit. Got the hose off yesterday and a new one back on today. What a miserable job! That short hose, about 11 inches long is really tough to work with. I has very little flex and has to bend to connect to the hyd pipe that runs back to a hyd hose under the floor panel.

Even with the grill housing tilted forward there still isn't enough room to work in there. I think the backs of my hands will carry scars the rest of my days. Anyway it's done and no leaks there now.

I've mentioned that I haven't had the dozer very long. but I didn't know that it has power steering. apparently the leak has been there a long time and I didn't feel any power assist in the steering levers. Needless to say the power steering reservoir was just about empty. If I hadn't parked the crawler on railroad ties so I can get under it to put the belly pan on, I would never have seen the leak.

On another note, the right side main hyd cylinder is leaking. That is why the main hyd. reservoir was low. I had to add two quarts of fluid to bring the level up to midway on the sight glass. My question is, is it an ok job to rebuild a cylinder in my shop or is it a job for a yellow John Deere shop? The shop manual states that rebuild kits are available. Does anyone have any experience rebuilding one?

Thanks for all the help on the hyd. leak. Glad it's fixed.

[jdemaris]

:

That is why the main hyd. reservoir was low. I had to add two quarts of fluid to bring the level up to midway on the sight glass. My question is, is it an ok job to rebuild a cylinder in my shop or is it a job for a yellow John Deere shop? The shop manual states that rebuild kits are available. Does anyone have any experience rebuilding one?

I don't recall ever seeing a 350 or 450 with power steering that DID'T leak.

In regard to repacking the cylinder - it's easy and the parts are generic. Yes, it's easier to buy from Deere as a kit if convenient. You can also just buy all the parts by size from anybody that sells hydraulic parts - they are standard Chevron packings - nothing in there that is special for Deere.