440ic hydraulic question

[GalenB]

I recently picked up a 440ic and got running (albeit I need to do a little more work there on the carb to get it running smoother without the choke). It has been sitting for several years under cover and I don't know much history. I know the clutch is stuck, but I'm just kind of trying to assess things before it gets too cold here to figure out what all I have to do.

Once I got it running this afternoon, I decided to raise the blade (single spool, inside the track blade, manual tilt and angle). Pulled back on the lever and the blade went down, lifted the crawler up. I thought this was reverse what I expected. Pushed forward and it settled down, but the blade didn't raise. It doesn't really seem like it's doing anything to lift.

I read some old posts that suggested on a similar problem it could be the cylinders, and I guess it could be one cylinder bypassing the cup or something. Is there a good way to troubleshoot this? I'm not real well equipped to do hydraulic work (including knowledge), though I've gone through a couple pumps and cylinders and some tractors. I just don't have pressure gauges, tons of fitting and hoses and all that.

I suppose I could probably reverse the hoses to get the blade up, just so I could drive it around and see what other surprises pop up too. I appreciate all the information and knowledge shared here on these machines, and any advice.

Galen

[dtoots1]

GalenB,
Dont recall seeing your location n your profile, it is good idea to show that info, someone could be nearby.
Check your hydraulic fluid level also to see if milky...that means water is in it...Use Sea Foam...should take about 2 or 3 ounces to clear it up...Next is rebuilding the lift cylinders is really easy..somewhat messy...but can be done with basic mechanical skills...you can either get parts needed from Lavoy owner of this site or your local hydraulic shop..
He also has all parts necessary to rebuild the steering clutches....that is a bit more of a job...tho first thing there is to go thru the adjustment procedures in the book and follow closely as will probably need adjustment several times. If needs torn down after you try all that...you will need to get dozer either in shop w.solid floor....drive up on 2 planks under each track and then block up with solid wood blocks to where you can comfortably reach disassembly etc, you will need some type of lift or crane to handle lifting the final assembly out as is bulky heavy and awkward as well as needs to be turned to clear the rock guard....will also need to split the track on that side...which requires turning track so find the master pin and set it up at the 1 or 2 o'clock position at the rear where you can drive the master out

[GalenB]

Thanks for the reply. Location is in my profile unless there's a setting I'm not seeing that blocks it...I'm in Iowa.

The hydraulic oil looks good. I reversed the hoses to the cylinders so when I pull back the control lever it lifts, and it does lift and hold, but when I push forward the blade drops, but doesn't lift the front of the crawler like it did before I reversed the hoses, so it seems like a gravity drop. The problem seems associated with the forward control position. If the cylinders were strong lifting the front, and strong lifting the blade with the hoses reversed, both with the lever in the back position, would it be the control valve that needs rebuilt?

I took it for a test drive to see how everything worked. The steering clutches work ok. I drove it around a for about 15 minutes or so. The foot clutch is the one that is stuck...probably going to have to pull the engine to get that to release. The pedal feels good, its just never disengages when you push on the pedal. I was kind of hoping I'd get lucky and it would pop loose while driving.

[gus]

If it only works one direction, depending on which way the hoses are connected, it's not the cylinders. It's either the control or hoses. Something is plugged in the non working direction\set of hoses. Valves not operating correctly.

Might try disconnecting right at the valve to see if there's flow coming out and if it's the valve.

[Lavoy]

99% of the time it is the cylinders, but in your case, it appears to be the valve.
Lavoy

[GalenB]

I pulled my control valve off this afternoon and pulled it apart as much as I could. I was hoping I'd find something obvious that would wash out that was keeping the middle check ball (in the diagram as seen in the manual SM-2023 180-15-5) from seating, but no luck. I'm having a hard time understanding how oil could be bypassing, short of that check ball not seating/bypassing and the pressure relief being set too low. Of course I don't have the special tool to pull the pressure relief ball seat; any suggestions for a spanner socket? And the plug for the front check ball is giving me fits not wanting to come out.

How critical is the special tool T9 for installing the front seal?

Thanks

[Lavoy]

I think there are square orings up in the bore, is one of them damaged?
Lavoy

[GalenB]

I thought there was one at each end, one at the control level end, and the other right before the float detent assembly, but I'll take a closer look when I get home tonight and really inspect the bore closely.

[jimmydiesel]

Galen
After you get the control valve back together if you still have the problem I think you should look at the cylinders.
If your dozer has the original cylinders they would have had leather cups on the piston. If those have completely fallen apart or the piston had come off the rod. Oil can bypass to the other side of both cylinders and cause the kind of problem you have.

If that is the problem it would be only lifting with one cylinder so you may see the lift frame flexing.
Steve

[GalenB]

I think you're on to it Steve.

I was able to get another of the check balls out (still can't get the one on the relief valve side out due to not have a spanner socket), the one on the front with the big screw plug. I put the spool back together last night and hooked everything back up. Raises strong. When I push the lever forward, now after dropping to the ground, its actually lowering the blade too, but really slow. It will raise the crawler off the ground, but I noticed the frame flexing and came to the same conclusion as your suggestions.

I'm going to service the cylinders, flush the system, replace the hoses, check the pressure and go from there. Thanks for all the information.

[GalenB]

I pulled the cylinders apart and to my eye the Leathers look pretty good in terms of no tears or deformities. I'm not real sure if I should go ahead and replace them. Can it be they've lost their flexibility?

https://photos.app.goo.gl/peJXG9K2iB9tY6BB8

[jimmydiesel]

In the picture the seal cup on the right looks very worn on the far side. Yes they should be replaced.
Steve

[jimmydiesel]

If you are just wanting to get buy for a short time you could expand the lips and put the best one on the lift side of the piston. On the side towards the blade. Best thing to do is replace.

[GalenB]

Thanks Steve. It's probably not as distorted as the picture makes it look, but it's ever so slightly worn on the lip, so I'm going to assume its bypassing. It came off the piston side too, which was the side that seemed to have issues on lowering the blade. I dropped one side of cups and o rings off at a local hydraulic shop to see if they have them or can make them cheap enough. The barrels look good inside. I guess I'll clean them up, hit them with a hone and put the new cups and o-rings in and see what happens. Oil change/flush too.

I've got to rebuild the generator and get the charging system working, as well as take another go at the carb. Can't seem to get it to run without the choke on, and then the governor is hunting some, so I've got plenty to do until I get the cups and seals. I received a pressure gauge today that I ordered, so I need to make a trip for some fittings so I can hook a hose up and see how the pump is doing too.

[jimmydiesel]

Galen
Before pulling the engine to replace the clutch. Try pushing with the blade. Run the dozer in 2nd or preferably 3rd gear, get enough dirt in front of the blade that you need full throttle. Keep the clutch pedal down. If it breaks loose just let the pedal up. This will put maximum load on the clutch. A ultrasonic cleaner is great for cleaning the internal passages in the carb.
Steve