Cat d4d 78a1594 broken hydraulic cylinder rod not sure what size rod or part number is needed

[CaptainB]

So I changed the hydraulic hoses of the old d4d and everything was fine for 15 minutes then the rod of the hydraulic cylinder left side got separated from where it’s supposed to be screwd into pics:

I measured the cylinder but I’m not sure about the length of the rod and I think this rod was welded “Mexican style” by the previous owner so I bet I’ll need to take that metal bracket where the rod screws into to the shop for rethreading

Also I’m thinking I’ll need to buy a hydraulic cylinder repair kit with all the gaskets etc needed not sure which one to buy either

Finally I’m thinking maybe I should do both sides to make sure both rods are same size, before this happened one rod was probably longer than the other the blade being always higher On the right side than the left which made uprooting trers shrubs etc more difficult

Would appreciate any comments advice etc thanks

Jose

 

[Nige]

The key to knowing what Part Numbers are involved is not the tractor Serial Number, it is the S/N of the hydraulic control. You will find that number stamped on a plate fixed to the hydraulic tank. I would guess that yours will be a 143 model of some flavour or other but I see at least 10 different versions, so it would be nice to know exactly which one you have.

 

[CaptainB]

The key to knowing what Part Numbers are involved is not the tractor Serial Number, it is the S/N of the hydraulic control. You will find that number stamped on a plate fixed to the hydraulic tank. I would guess that yours will be a 143 model of some flavour or other but I see at least 10 different versions, so it would be nice to know exactly which one you have.

Ok niege! thanks I will look for that plate and update my post thanks!

 

[.RC.]

The rod needs replacing anyway by the look of the condition of the chroming.

 

[pittsburgh cat man]

Are you sure that is a cat blade, I sure would like to see a picture of the whole blade

 

[CaptainB]

Are you sure that is a cat blade, I sure would like to see a picture of the whole blade

It’s a balderson blade this is a d4d with toolbar

 

[pittsburgh cat man]

I don't know how balderson is for getting old parts it might be a problem I would check hyd. shops, around here a lot of shops will put a new rod on your rodend

 

[Welder Dave]

The rods seem pretty small dia. for what they're doing. It might be possible to have new rods made a little bigger dia. but would have to see if larger seals for the gland are possible. Even 1/8" bigger would be an improvement. You'd lose a little lift capacity but I don't think enough to make a big difference. The barrels look to be pretty big dia. The break isn't even what could be considered a weld. I'd look for way to better route the hoses. They are just waiting to get ripped off.

 

[TomA]

Blade tilt is not effected by the cylinders. Turnbuckle on vertical brace on either side will tilt blade

Why not try "improved" Mexican style weld.
Bevel it good and go after it with 7018. If it breaks, fix it again.

If it doesn't leak too bad, don't worry about the rod for now.

 

[LCA078]

Agree with TomA. The tilt cylinders should "float" relative to each other unless that blade has a unique set up. Even if cylinder rods are slightly (not excessively) different in length, welding it up correctly is the most straight forward fix. Grind off the old welds and weld it right.

 

[Welder Dave]

Cylinder rods need to be beveled for at least a 3 pass weld. Preheat would be good.

 

[LCA078]

I know it might be a PITA to remove the cylinder from the machine but taking it into a bona-fide weld shop for a bench repair may be your best bet. I'm sure there are good welders who will bring their truck to your dozer but I generally find better jobs happen when I bring the pieces into a shop and let them work on it as needed. This is not a complex repair so I don't think you will go wrong either way. Welder Dave is spot on with prep work being very important.

 

[Welder Dave]

I was never suggesting a field repair unless the the cylinder was removed and the rod could be roll welded. Best would be to chuck the rod in a lathe to bevel it. The eye could likely be ground with an angle grinder.

 

[LCA078]

This probably the only time I'll ever disagree with you Dave but I would not trust the average machine shop with a lathe on a cylinder rod. I'd trust a good machine shop, but not an average shop, to not damage the chrome on the rod.

To not damage the chrome when using a lathe, a machinist would use soft jaws that are machined out to the size of the rod...which is very easy to do if you already have soft jaws set up on a chuck. But most machine shops that I know don't even know what soft jaws are nor would they spend any time on the lathe set up to use them. Instead, they would just clamp the rod with any 3 jaw chuck with banged up hard jaws that was already on the lathe and take a honking bite to quickly bevel that rod. This almost ensures they will bury the bit and lock it up in the surfaced hardened material that causes their slick rod to slip in the chuck because it only gripped by a few high points on the banged up jaws. And then there goes your chrome where you chucked it.

I recommend just using a stand-up belt sander with 80 grit to bevel a cylinder rod by hand, or any rod for that matter. Even a Harbor Freight version will bevel that tiny rod way faster than it would take a machinist to even set up a lathe...much less use it.

Lots of words from my side but those are words of experience to help keep others from getting their precision surfaces jacked up from "average" machinists.

 

[Welder Dave]

Grinding would work but there are machine shops and hydraulic shops that work with cylinder rods all the time. I just suggested beveling in a lathe would be the best way to bevel it. I wasn't suggesting having an inexperienced shop do it. There are much softer metals than hard chrome cylinder rods machined in lathes everyday. Standard chrome would be more of an issue.

 

[LCA078]

No worries- I know you weren't recommending an inexperienced shop or such to work on the cylinder. I just know the area where the OP is located and let's just say there is a wide spectrum of shops and capabilities he can use to repair his cylinder. And most of them will say "Ahh, that's an easy job- if you have cash, I can do it while you wait."

With all our posts on how to correctly repair his cylinder, he should enough knowledge now to ask the right questions to ensure he gets a good fix.

 

[Welder Dave]

Yeah, there are some shady shops that cut corners.