I have a D4H with a 6 way blade. The problem is the blade will not hold an angle. It moves back an forth like it should in the air, without any resistance. When you drop it on the ground it moves when you hit something. Any Ideas
Several. You may have a loose piston head in the angle cylinder which is allowing oil to bypass. That same piston may have damaged packing, may even be cracked or damaged itself. The valve that operates that circuit may be mis-adjusted or damaged -- either the spool or the valve body (cracked). The pressure relief for that circuit may be damaged or may have some debris holding it open, could be a piece of steel or packing. The spring for the relief may be damaged or busted. The relief seat may be cracked. The upshot is that before tearing stuff apart, get some pressure testing done. Call the Cat house and talk with a service advisor to get some additional ideas on what you might do yourself to narrow down the problem cause. Good Luck!
D4h This is one of those "just started happening problems". It has 2 cylinders for the angle, one on the left side and one on the right. Neither side will hold when pushing.
surfer gave good advise, a set of pressure/flow gauges should tell you where to start looking. I assume none of the other functions are affected. Like can you lift the front of the machine up, and it stays there?
A basic test without any gauges, is to extend the cylinder all the way to the end of its stroke, and remove the hose from the opposite end, (the end that would make it retract). Then with the engine running, pull the lever as if you wanted to make it extend further. If oil comes out of the fitting on the cylinder, there is a problem inside - piston/seals etc. If no oil comes out, the problem may be elsewhere. Try it also with the other hose with the cylinder retracted. Test both cylinders. Make sure you pull the lever the right way.
Hi I Had A Very Similar Problem I have a d4h and I had the exact same problem about 2 years ago. One minute it was working fine and the next the blade angle would not hold. There were no leaks on cylinders so I figured it might be orings/packing in one of the cylinders. I pulled both cylinders off and was draining the oil out of them when the piston rod in one of the cylinders pulled clean out of the cylinder. After taking the cylinder apart it appeared that the bolt holding the piston to the rod had backed completely out[for no apparent reason] and was rattling around in the cylinder barrell ruining everything except the cylinder rod[which was perfect]. I had to find a used cylinder to get me up and running. This happend on a 4k hour machine and on a factory cylinder that had never been rebuilt or taken apart. P.S. iF YOU FIND YOU NEED A CYLINDER ROD i HAVE ON IN PERFECT CONDITION.
Roddyo, are you going to let us know what you found?
D4H Problems Solved Sorry about not getting back to everybody. I have been running my excavator and the dozer has been on the back burner. We sheared the bolt that holds the piston to the ram. I didn't know it but D4H's are bad about this working in timber. The guy I sold my last excavator too also has a D4H, he carries 2 or 3 of these bolts in the door of his pickup. He told me he averages breaking 1 a week when he's busy. He said it's just a 5 minute breakdown. Thanks for the intrest Tom, if you would like to see how us small time hillbilly's in the U.S. operate check out my website www.rodneyobrien.com it has a few pictures of some work we do. Thanks Rod
allot of guys build solid links to pin on when pushing timber. Also make sure you torque the bolt, too tight is as bad as not tight enough.
D4H Problems Solved I usually use my Track Hoe to take down trees and pile with the D4. I only use the Dozer taking down Trees on small jobs. I really think this is only a problem digging out stumps. The big problem here is I wasn't running it when it broke and it was at the end of a job. There's nothing like moving to another job an hearing over the phone, "Oh by the way". ointhead Another Problem is all my experence with these D4H's was pushing dirt and they were considered Toys. We just used them to Winch and grade the Right of Way.
A lot of people dont understand this one. The one that really shows this to be true are Shears. If a bolt is not torqued, the shear will snap it in a matter of days rather than weeks.
Bolt Shearing This is a case of "I Really Don't Know What Happened". I don't know if the bolt sheared or backed out and then broke when the cylinder bottomed out. Where we were working wasn't that rough, mostly saplings with a few odd stumps. We were pushing out a 40 foot Highline Right of Way. On one hand I think it was one of those "ODD" stumps I was talking about. On the other hand I've worked on enough stuff to know that when you have a problem with a machine you ask yourself what was done to the machine Lately? In this case that cylinder was rebuilt about 200 hours ago. So I think it could go either way. By the way I got a new guy rebuilding my cylinders now too.
Thanks for the link to the website Rod, I was interested in the outcome of your problem as we have a D3 with a 6 way blade for farm work. I will keep it in mind if we ever encounter the same problem.
You Can Never Know Too Much That sounds good Tom, if I can ever help you with anything just ask. We are getting a pretty good discussion going on burning timber, you might find it intresting. Rod
having problems with d5c dozer stopped tracking dead in its tracks