I have a 850g case bulldozer. After running it for a couple hours my hi & lo levers and my control for the blade gets real stiff and starts to stick. I am lost. It's not building pressure in the tank and the oil is fresh. Any help would be greatly appreciated. Thank u for your time.
What type or brand of oil are you using? It sounds like the oil doesn’t have any lubrication in it.
Are your blade controls a simple hydraulic valve, not pilot operated? Are the covers on the bottom of the spools seeping oil?
I want to apologize in advance for my ignorance. I'm not the best mechanic I only work on my own stuff out of necessity. I use extreme brand hydrolic oil from Napa. My father uses the same oil in 3 dozers and other equipment. As far as the controls go. I'm pretty sure they are valves. There is plastic covers on the bottom of it. And they do leak a little oil. But they have been doing that for a year or better. Thank you for your responses. It's very much appreciated.
I'll take a picture tomorrow of the blade controller
The 850G is a manual control valve. The leaking has nothing to do with spools being stiff. You said that your transmission controls were stiff also. I would look at chemical contamination. I know weed killer will play heck with hydraulic system. Has anyone added oil to systems out of a different jug.
If the bottom of the spool is leaking, and the spring end is usually covered with a small cap with a vent hole, that cap gets full of oil, and the spool will not go that direction at least, the weep hole will not move enough oil to let the spool move. Leave it overnight and the oil drains out and it runs fine for an hour or two the next day, before doing the same thing, making you think it's temperature related. That's why I asked about leaking, I've seen it on a couple different brands, but no idea if that's happening here, or even possible. If it locks up, and you remove the cover which is usually two small bolts or screws, and the cover is full of oil, but it works without the cover, then it's usually just o rings to fix, and you only need to remove the springs, the spool can stay in place.
I can’t anybody to grease it, much less check the oil. I’m the only one that adds oil. (This might be relevant) I burried in a pond about a year ago. Had mud up to the bottom of my seat. I got pond water in my hydronic system. I flushed it out 4 times with fresh oil and a filter. Before that my brakes didn’t work After I flushed the system my brakes work perfectly.
Delmer: if I take the two screws out of the plastic cover the only thing that will fall out is the spring. Is that correct? The reason I haven’t tried to fix the leak is I was afraid of a bunch of parts falling out
A pic would help, I don't know what the plastic cover is. I expect to see a small aluminum/cast pot metal type cover over the bottom of each spool with two 1/4" bolts holding it on, and weep hole that's clean oil and dust covered oil all around it. The spring should be attached to the spool. One spring provides pressure both ways, you'll understand when you take it apart.
You may still have some pond curd in transmission and hydraulics, it's hard to get that crap out.
I have just gotten into the side panel where my current blade controller is. I don’t have any O-rings or gaskets it’s metal on metal. And I am going to upload pictures of it
The very first one I took off has a hole all the way through it
Yes, that's a healthy sized weep hole, I don't think you had any oil building up in that cover with a hole that size. How about the other cover, was the hole big enough to see through? I don't know what kind of seal is there, I'd expect to see an o ring under the spring, but it doesn't look like there's one there, maybe a seal inside the bore, and you have to pull the spool out to get at it?
I think you need to remove the blade control valve and disassemble it so you can clean it up. Look for any sign of trash or mud etc... You can remove the spools and use a fine emery cloth or sand paper to clean spools.
I took the valve off and took it to the local machine shop. The seals in it where dry rotted and broke into pieces. It was leaking out the top pretty bad. And I’m sure it was leaking out the bottom just as bad. All the seals where roached. There are 3 valves. The outside two had weep holes. The inner one did not. So what do u guys think. Is this my problem. I should have it back in a day or two
You'll know if it works before we will. Let us know how it turns out.
Yes sir. Will do.
Stephen, while it is at the machine shop. have them check the spool for straightness. I just had my hoe front bucket tilt spool straightened. Hot, it was terrible stiff. Was out 20 thousandths
Has this always been a problem for as long as you have had the machine? or is it something that has only just started to happen?
No sled dog. This is a new issue. It just started this after sitting all winter and me putting a new head gasket on. I’ve got my valve back from the machine shop and got it put back on the dozer. I’ve rain at some and the blades haven’t stiffened up. But, they only would start doing it when I was really putting the machine under load. I have not yet to really work it yet. Another issue I’m having isIs taking a long time for it to move after sitting overnight. It Hass to warm the fluid out before it will move. My sister has the exact same dozer and hers takes off immediately even if it’s 0°
Are you and your sister both using the same oil in hyd. and tranny? What pressure is showing on dash for trans? Have you checked trans pressure with a manual gauge? Is your oil level correct?