CK25 BLOWN HEADGASKET

[RADDAD50]

I have a CK25 with 478 hours, the headgasket blew today. Do you have to remove the fuel tank to replace the headgasket ? I have changed many headgaskets on gasoline engines. Are there any special tools needed. I was looking at the online manual and it looks pretty straight forward.

Thanks, RAD

 

[SSdoxie]

Don't think the fuel tank has to come out but not sure. I would take the hood off rather than work under it, and take loader if it has one. No real difference in gas or diesel procedure, remember to set valve clearance.

 

[VictorW]

You may want to get new head bolts for reassembly. A while back another member changed his gasket only to snap one bolt when he torqued them back down to spec. They may be one time use like they use on many cars and trucks. The cost is reasonable considering the amount of time he spent removing the head again to retreive the broken bolt.

 

[whiskywizard]

I have a CK25
Do you have to remove the fuel tank to replace the headgasket ?

Aren't the head gasket and fuel tank at opposite ends of the CK25? Maybe this isn't the job for you try on your own.

JK

Sorry to hear of the issue. Any idea of the cause yet?

 

[PoorMansCat]

THis seems to be a re-occuring theme...
I am wondering if re tourquing the head every 100 hours would prevent this failure.
As Victor already suggested, REPLACE the head bolts!!.. apparently these are torque-to-yield bolts and should NOT be reused...
Maybe rather than retourque, another bolt manufacturer should be sourced??..

 

[MotorSeven]

THis seems to be a re-occuring theme...
I am wondering if re tourquing the head every 100 hours would prevent this failure.
As Victor already suggested, REPLACE the head bolts!!.. apparently these are torque-to-yield bolts and should NOT be reused...
Maybe rather than retourque, another bolt manufacturer should be sourced??..

"Torque to yield" that's a good name for them. On a VW TDI they use many "stretch bolts"...same thing. As you torque them down the threads actually stretch out locking the bolt in place and this is why they are a one time use only bolt. Many of timing belt jobs by owners have failed because they re-used the old bolts, which causes pistons to hit valves...not good.

If I am not mistaken, Kioti includes new bolts with the new gasket...maybe a Dealer can confirm.

 

[RADDAD50]

They headbolts do not come with the headgasket. I ordered them with the new headgasket they are $5.25 each and there is 14 of them. I will post when I find out what caused the gasket to fail if it is the gasket, I'm hoping it ins't a head or block warp or crack. Also you can't get to the back head bolts without removing the gas tank.

 

[VictorW]

I think you'll be happy that you spent the 70 bucks or so for the new bolts. It sure beats the hours spent pulling the head again if a bolt breaks. Of the members that have posted their findings after changing the head gasket, none have mentioned a warped head or block. They found a bad part in the gasket that let lose, reinstalled with the new gasket, and the engine now lives on without a problem. Good luck with your repair.

 

[PoorMansCat]

Not sure if Kioti requires a re-tourque, but I'm about convinced that it would be something that you might consider doing every 100 hours or so...

 

[Mike Gibson]

If they are stretch bolts I wouldn't be in a hurry to retorque them since they are already stretched. You just might find the yield point and ruin your day.

 

[RADDAD50]

How does everyone feel about the retorque of the headbolts after the first 30 minutes of running as the manual says to do ? Seems like an a lot of extra work to take the engine apart again retorque and adjust the valves after only 30 minutes of running ?

 

[VictorW]

How does everyone feel about the retorque of the headbolts after the first 30 minutes of running as the manual says to do ? Seems like an a lot of extra work to take the engine apart again retorque and adjust the valves after only 30 minutes of running ?

I would hope if the manual advises to retorque after 30 minutes, they know what "they" are talking about. The engine has had a chance to warm up and expand. I assume the engine is then allowed to cool down before putting a wrench to the bolts but the manual doesn't make any mention. Checking the valves must mean that the head gasket will crush more. I've never done this with any gas engines but diesels may be different. I'm sure some members will share their experience and knowledge.

 

[PoorMansCat]

Not sure about an engine this small, but on all the diesel and natural gas engines we build, (which is hundreds a year) All of them get a valve adjustment after a 4 hour full power dyno run... They are allowed to cool overnight then get a valve adjustment.
Our engines do not require a re-torque, but if in your manual it calls for one, then yes, you should definitely take the time to do a full retorque.
Kinda makes you wonder if they call for it in the service manual, How do they do it when the tractor was sold new??? Maybe thats whey the Kioti seems to be a little more prone to head gasket failures..
I would still consider doing an annual torque check..

 

[DK35vince]

I can't find anything in my manual (DK 35) that says the head bolts need re-torqed.
I'm at 1600+ hours and have never re-torqued the head bolts.
No plans to start messing with them now.

 

[VictorW]

I can't find anything in my manual (DK 35) that says the head bolts need re-torqed.
I'm at 1600+ hours and have never re-torqued the head bolts.
No plans to start messing with them now.

The only place in my Kioti manuals that call for a re-torque of the head bolts is in the service manual when you replace the head gasket for whatever reason. It's not listed anywhere as a routine/scheduled service.

 

[DrRick]

My john deere 450 dozer was rebuilt, and the manual said to retorque. I did not and found out it is stated for a reason. I was blessed with a sudden head gasket failure, and the next time I spent the 2 hrs to retorque. Have not had any more troubles since then. (many hours).

 

[blue262]

The gaskets fail because of what's called insufficient "gasket margin" area around the cylinder and coolant ports. The width of the gasket material in these areas is minimal. Eventually the 485 psi cylinder pressure erodes a path to the 10 psi coolant port. Engineers try to keep the block compact to save manufacturing cost.

I would replace the head bolts, I believe the torque value in the manual is near the "plastic" range for the bolt material.

The manual does not require re-torqueing and I don't think it is a good idea based on the previous sentence.

 

[Coyote machine]

A different head gasket may be used when the factory builds the engine than when one does a head gasket replacement- can't say for sure but it is possible. And who's to say the original engine build does not require a retorque?
New head bolts can't hurt, and i would assume they are meant to be installed dry- that is not oiled, because that would change the torque result.

 

[RADDAD50]

Update: I removed the head and old headgasket. The headgasket had failed at the water port next to #1 cylinder @ gear end of engine. This water port seems to be really close to the cylinder. Everything came apart with no problems but now I'm ready to put everything back together and it says in the service manual to adjust the valves remove the timing check window and turn the flywheel to 1 TC. Well in order to remove the two bolts that hold the window plate in place I have to remove the right side of my FEL and backhoe support bracket which looks like it has about 14/ 3/4" bolts and weighs about 200lbs. I wish Kioti would have cut a hole large enough in the Fel bracket to be able to see this inspection window? So for all you people that want to do a valve adjustment be prepared to remove your FEL and backhoe bracket.

 

[blue262]

If you follow the instructions in the manual to set the valves it would require removing the FEL. But you didn't mess with the cam, chain or anything else that would mess up the timing, your just doing a head gasket replacement. To adjust the valves just turn the engine over until the valve spring is unloaded and measure the clearance and adjust to the specs.