D2 piston ring replacement

If you do replace just the rings, don't neglect to remove the ridge at the top of the sleeve. It will make the piston easier to push up and wil keep the new top ring from hitting a "step" and possibly being damaged or beating the top ring groove out.

Yes, you should be able to manage the rod caps through the inspection covers. Helps to be younger, smaller and more flexible. Also may need an extra joint in the forearm area😆

Using the manifolds to pressurize the cylinder/check the valve is hard because you may have more than one valve open at one time. Use the injector hole, but you cannot get enough flow through one and it should take ~400 psi to 'crack" the valve.

So remove the injectors, set each cylinder in turn to TDC compression stroke using the marks on the fly wheel and the valve positions, Put the transmission in gear, engage the main clutch and set the foot brake so the engine doesn't suddenly turn when you put pressure on a piston. Removing all the injectors will absolutely prevent the engine starting if it were to suddenly turn on you and you can easily check all of them and may find something you missed listening to the bad one. Simple disengage the main clutch each time you need to turn to the next TDC position and reengage to lock it before applying air pressure.

The CAT proceedure is to pressurize, shut off air and watch the rate of drop or something like that. Most folks just apply shop air pressure and listen for where it is leaking by. Always will have a little leaking into the crank case past the rings, so that will be a judgement call as to what is too much, but shouldn't have any leaking into exhaust or intake manifold.

While you have each piston on TDC compression stroke, you can roughly check valve clearance by adding a couple thousandths to the 0.010" hot spec used for all the old engines. Might find your trouble there if you have way too much clearance (stuck valve?) or not enough to let the valve close fully.

You can usually adapt an air line connection to the Precombustion chamber threads, but be careful to engage the same threads as the hold down nut of the U series tractor injectors or you may remove the "retainer" which seals around the top of the PC chamber and keeps the coolant in! I torched a hole through the center of an old capsule type injector (way too hard to drill!) and used the connection on top of the adapter where the fuel line usually goes to pressurize them the last time I did this.

If you have the older style injectors on a J series tractor with the return line connected across the tops of all 4, Someone can guide you to the discussion about building a socket to remove those.

Thanks again Cc.
Your information is very helpful. I know what I need to do now. It's a bit cold up here in Wisconsin now, so I,m not sure when I,ll get back to my Cat. It may need to sit until spring.

If you pull the sleeves, the piston and rod can come up through the block with them. It's extra work, but I believe I would at least consider resealing the sleeves and checking the sleeve protrusion if I were that far into the engine already.

Otherwise, compressing the bottom oil ring in bottom assembly isn't too hard with the others left off. Put pistons in with bottom ring and push them out the top. Then you can install the top rings.

Put a piece of radiator hose over the throw or you'll ding it sure as h***!

(Way back in the old posts I have a complete assembly sequence with photos for D2 5U, if you can find it.)

Good luck!

Jack

If your D2 has the D4400 engine in it...you can unbolt the rod caps from the inspection covers.
I did this with my engine although its a power unit on a skid.
I pulled pistons and liners.
Was not an easy job and took a couple evenings.
I am sure that if you had one of the "WHITE COATS" that the Cat service guys wear in the manuals you could do it in an evening.
Best of luck to you and remember we all like pictures, its our candy.
Regards Chris