Welcome to my Nightmare!!!!

[EddieWalker]

Let me start out by admiting to not being very smart and to not having any idea of what I'm doing most of the time. This particular thread is going to be about my diesel engine in my dozer. I'm totally outside my comfort zone and really don't want to deal with the problem, but I have no choice. I have to fix it and need to do the work myself.

My 1989 Case 1550 dozer has a Cummins 8.3 turbo engine in it. I just rebuilt the Turbo and have learned that oil wont drain from it due to excessive blowby. In fact, the blowby is so bad that it's creating positve preasure and forcing the oil out the seams in the turbo.

A guy I met came by the other day and told me I had a hole in my piston. To prove it, just remove the fuel lines one at a time and see which one doesn't affect how the engine runs. Number 6 cylinder is totally dead.

After sratching my head and walking around in circles for awhile I know what I need to do. Replace the piston.

Now this is where I'm hoping for some advice and help.

Can I remove the oil pan and pull the piston out without taking off the head?

Should I replace all the pistons or is there a way to check to see if they are still good?

Do you do anything to the cylinder walls before putting in new pistons, or will they seat themselves after awhile?

Can I just replace the bearings on the crank with new ones or is there something i need to do first?

Is there a website with torque specifications for a 1989 Cummins 8.3?

What am I missing and how bad of an idea is this???

I'm realy an idiot on diesels and my experience with gas engines was 20 years ago in my youth.

Please help.

Thank you,
Eddie

 

[Bird]

Whew, Eddie, I have no idea how to do it, but wish you luck, and be careful. When I was a project manager on a construction job, they had a dozer that had to have the head pulled on site once, and I don't remember what the original problem was, but when the mechanic finished and they fired it up, it blew a great big hole out the side of the block. Seems the mechanic left a small wrench laying on top of a piston in one of the cylinders. /forums/images/graemlins/laugh.gif I don't know whether he ever found another job or not. /forums/images/graemlins/laugh.gif

 

[Jimbrown]

Well Eddie I am not a cummins mechanic but I have lived a lot places in the world where the word part was a nonexistent word. And this advice will go against almost any mechanics recommendation but here goes. Plus they used to do this all the time on great big old radial airplane engines. I don't think you have a chance of pulling the piston from the bottom. You will have to pull the head. I looked at a picture of an 8.3 and it looked like a single head. Some of the bigger diesels have separate heads for each cylinder or pairs of cylinders. Does not look like yours does.
I get the idea you want to do this cheap and a whole rebuild is not wanted (read big bucks) Most people will tell you not to do this but I have done it. pull the bad piston hone the cylinder as best you can with a hone and electric drill put in a new piston, rings and bearings on that rod. There will be a ridge in the cylinder right at the top of the rings. They make a special toll to remove this ridge. Any good auto place will rent them. Remove the ridge before installing the new pistion. If you do not the ridge might break the new ring. Leave the rest of it alone unless one of the other pistons or cylinder walls look really bad. And I mean really bad. The fewer things you touch or remove the better off you are. I will probably catch flak over this but sometimes you got to do what you gotta do.

 

[Syncro]

Eddie, for what its worth I had a similar problem with a Case backhoe. Turned out there was 1 bad injector that burnt a hole in the top of that 1 piston. Same symptoms, excessive blow by and oil blasting out of the breather. I had the work done by a mobile mechanic, but watched him do it. He replaced just the 1 piston and liner, left the rest alone, and the machine ran good as new after that. The head had to be removed, but the hole job took him less than a day start to finish. When I first saw the heavy blow by I too though maybe a whole new engine was going to be needed, but apparently a single cylinder can be rebuilt with good results. Hope its the same in your case.

Frank

 

[MMM]

I'm not certain, but it probably has a liner, so no ridge worries, just replace liner. You'll have to pull the head and the pan. I usually pull liner and piston together. Before you start, you should get a manual and a compression tester.
Good luck.

 

[Dirthog]

Think you will find that engine does not have a liner that you can replace in the machine they have to be pressed out & in if the liner is not too bad you can hone it and just replace 1 piston have done that lots of times. just make sure you find out what caused the problem in the first place. You will have to pull the head to do any of this so look real close at the other pistons and liners.

 

[tlbuser]

Shouldn't have any significant poblems replacing just the piston, rod and rings, but, the only way inframe is to pull the head and oil pan. If the cylinder liner is bad, you will need a wet sleeve puller to remove the old liner.
While it's this far apart, it wouldn't hurt to have the injectors tested / rebuilt.

These two links might help
valves

parts

 

[MMM]

</font><font color="blue" class="small">( if the liner is not too bad )</font>
Most of the piston melts, if that's what happened, I've seen have deep liner damage from slag and shrapnel.

</font><font color="blue" class="small">( Think you will find that engine does not have a liner that you can replace in the machine they have to be pressed out & in )</font>
Interesting info.
I think if I had to do that, it would be time for a different (type) engine. If it's not field servicable, it's not worth having. I would imagine by the time the engine was pulled and sent where ever, and installed again, another engine would be as cheap (counting the downtime). I imagine that sways a lot of partial rebuild decisions such as Eddie's.

 

[EddieWalker]

Thanks guys for the help and advice.

My first hurdle was to get the plate off the bottom of the dozer to get to the oil pan. This turned into a nightmare because all the bolts spun in place.

The area at the bottom of the engine on the other side of the skid plate has a foot of leaves, branches, dirt and oil to hold it all together. I tried digging through it, but could only get to one area and all the bolts were spinning.

I never found the nut or why it was spinning when I decided to cut off the heads of the bolts.

First I wanted to get the dozer up in the air to give me some working room.

Eddie

 

[EddieWalker]

I put three yards of dirt down for each side.

Than I used a piece of 5 inch square tubing on two pieces of 3/4 inch plywood to hold the blade up. The hyrdraulics should do this anyway, but for saftey, I wanted soemthing strong enough to hold the balde up.

Eddie