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Case 680E no compression on cylinder 1

iko

Member
Joined
Jan 19, 2022
Messages
15
Location
Ontario, Canada
Hello everyone, I've been reading a lot this forum, what a great source of information and helpful people. This is my first post.

The short of it is, I think I need to overhaul cylinder 1. But I don't know which sleeve and piston kit to order, there seems to be two different sleeve types, one with 5.092" TO 5.097" FIRE DAM DIAMETER SLEEVE, and the other with 5.189" TO 5.194" FIRE DAM DIAMETER SLEEVE. Is there a way to know which to get perhaps according to the serial number, or year of fabrication? This 680E I think it's a 1977 production.

Got a 680E this past winter for what I thought was a decent price but without any experience with diesel engines or this machine in particular. PO said it all works except for "a little blowby". Famous last words, as they say. Addressed some clear problems right away. The fuel transfer pump was leaking a lot of diesel into the crankcase, replaced the pump and at least the crankcase no longer got filled up with diesel.

The biggest problem it has now is that there's zero compression on cylinder 1. Tested for this because it seemed to me the engine wasn't running as smooth as it should, and cracked the injector lines one by one. Numbers 2,3, and 4 when cracked, change the way the engine run noticeably, but nothing changed on number 1. Then I got a diesel compression tester and checked each cylinder. Compression wasn't great on 2,3, and 4, but on number 1 it was zero, the tester dial didn't move at all.

Tried to see what's going on with a bore scope, and I think part of the cylinder is missing. Here's the video made with the bore scope.


Any help is appreciated.
 

iko

Member
Joined
Jan 19, 2022
Messages
15
Location
Ontario, Canada
I was hoping to order the parts and still use the backhoe while waiting for them, but I guess I'll have to take the head off and measure the sleeve to order the right parts. Oh well..
 

Old Doug

Senior Member
Joined
Oct 16, 2013
Messages
4,530
Location
Mo
You may avoid some thing else happening if you quit using it as soon as you can. Its tuff buying a machine and not being able to use it but when you get it running wright it will do alot of work you just need to be patience easyer said than done.
 

Tinkerer

Senior Member
Joined
May 21, 2009
Messages
9,366
Location
The shore of the illinois river USA
If it is a 680E it has a Case 336 cid engine. It is not possible for the fuel transfer pump to force fuel into the crankcase.
It has an electric lift pump inside the tractor frame for transferring fuel to the injection pump.
Like Bob said take it apart before ordering any parts. Then you will know what you need for parts.
You will need to remove a sleeve and measure the top of it to determine the fire ring diameter.
Do you have the service manual for the machine ?
 

DMiller

Senior Member
Joined
Feb 21, 2010
Messages
16,550
Location
Hermann, Missouri
Occupation
Cheap "old" Geezer
Based on previous examples of this, take the engine out of the machine, Strip it completely and clear all the metal in the systems. This needs a full overhaul NOT a piston and sleeve patch.

Will find embedded metal in bearings, bushings, in every oil rifling. This is a out of frame major you are looking at. While all apart have a Fuel Injection shop go thru the nozzles and pump, have a shop go thru the head and valves.
 

iko

Member
Joined
Jan 19, 2022
Messages
15
Location
Ontario, Canada
If it is a 680E it has a Case 336 cid engine. It is not possible for the fuel transfer pump to force fuel into the crankcase.
It has an electric lift pump inside the tractor frame for transferring fuel to the injection pump.
Like Bob said take it apart before ordering any parts. Then you will know what you need for parts.
You will need to remove a sleeve and measure the top of it to determine the fire ring diameter.
Do you have the service manual for the machine ?

It is indeed the 336BD engine, but it does have a mechanical pump directly on the fuel injection pump, with a plunger actuated by a cam the fuel injection pump. The injection pump is the 4 cylinder Bosch pump, timed by a gear from the crankshaft. The lift pump was dumping diesel in the lower side of the fuel injection pump and from there it made it to the crankcase. Well, I wasn't sure but the replacement lift pump fixed the diesel dumping issue.

I bought the service manual for this machine, yes.

Sounds like the head must come off . The previous owners must have used the machine with this busted piston for a while because it does work. Before I clued in to the cylinder missing I dug out 3 stump as well. The machine is crazy strong as is, but now that I know what's wrong with it I'm not happy to continue using it. Was hoping an in-frame overhaul would suffice, but from what you guys say I should pull the engine out. Now that's a little scary.
 
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