M25 overheating after New alternator bracket and hoses???

[sailingdolphin]

It never over heated before.  I put a new hose from the heat exchanger to the new copper elbow inside the bracket conversion kit and the new elbow hose in the kit that goes to the water pump.  I also installed the new bracket.  Salt water is spitting out of the transom and when I feel the plate where the impeller is its cold.  There is no antifreeze fluid loss.

BUT it heats up to over 190 before  I shut it off. I did this 3 other times and shut it off at about 185.   It got there very fast. Less than 5 minutes.

It also cools down fast.  

Please help.

[Ron Hill]

Doug : It sounds to me like you've got an air bubble(air block) in the 50% Preston internal coolant.  
Run the engine and open the bleed valve on the top of the thermostat housing until some coolant starts to come out.  You might have to do this a couple of times.
Anytime that you let air into the internal coolant system you need to "burp" the system and get all of the air out.  Usually happens when you change hoses, thermostat etc.  

[sailingdolphin]

Thanks for your response.  Unfortunately I spent the last 3 hours with no success. I will start to get fluid coming out of the bleed valve at about 170-180 degrees. I will not get any fluid until then.  I cracked the house going to the thermostat, is that the return line? I also cracked the line going to the water pump. Any other suggestions?

[Ron Hill]

Doug : You must have a bunch of air in your internal coolant system and/or your thermostat is sticking closed.

If the butterfly valve (AIR bleed) on the top of the thermostat housing won't let all of the air out(you open the butterfly and then close it when fluid appears), here's another solution to get that air out:
Remove the lower hose going into the thermostat housing.  Take the cap off of the coolant reservoir.  Insert a pump (like the PAR Little Pal) into the end of that hose and pump the fluid into the reservoir until you get all of the air out of that system.  When you stop pumping, quick remove the pump and cap the top of the hose with your thumb.  Reattach the hose to the housing.  Attach the cap and you should be OK.

If the thermostat need changing, remove it and go to your Kubota dealer with the old one and get a new 160F/59C replacement(with a new gasket).

BTW, I'm sure that you looked/blew thru the new hose and 90 degree metal elbow to make sure that they were clear - before installing?!?  

[Mark Wey]

Doug, it is a long shot but I have seen this before. A hose will delaminate on the inside and when you create a vacum in the system a bad hose of this kind will delaminate and block off the water from the inside of the hose. The out side of the hose looks normal but the inside is not. Of course the only way you can tell for sure is to get another hose and see if the problem re-occurs.

Just another possibility!

Mark

[DEMERY]

Open the butterfly valve on the thermostat housing and rev the engine. It's been my experience that you need to run the engine at high RPM's until you only have liquid coming out of the bleed valve.

Good Luck,

Dave

[Ken Juul]

Could be that the air bubble is in the water heater.  Takes a while to self bleed.  Disconnect both hoses going to the water heater and pour your coolant in until you get some coming out the other hose.  Reconnect and continue bleeding.  If you are going to change the thermostat, I think one of the hoses attaches to the thermostat housing.  Leave it attached, take off the other hose and pour the coolant in the thermostat housing.  Only have to deal with one hose that way.

[Stu Jackson]

Searches on "coolant" and "overheating" provide a wealth of information and ideas.

[sailingdolphin]

I put the little pal in the return line pumped about 10 times  then Filled up the line with fluid put my thumb over it-reinstalled the line and it worked.

Thanks for all your help.

[Ron Hill]

Doug : Glad that you got your problem solved.   I use that Little Pal pump for some other uses:

Anytime I need to get the raw water prime back up to the Oberdoffer/Sherwood pump, that Ltl Pal does the work.  It's a two person job, but it takes all of the strain of getting the water to that pump and into the cooling system/heat exchanger.  
You remove the inlet water to the raw water pump.  Insert the Ltl Pal in that line and make sure that the thru hull is open.  Then pump into a bucket/coffee can and when the water starts to come out have someone turn off the thru hull and again put your thumb over the end of the hose.  Re attach the hose, open the thru hull and start the engine.  You'll be amazed that the water starts to come out of the exhaust immediately with no reeving of the engine!!

I also use the Ltl Pal to suck out the filled Xmission after winter layup.  Then I add new fluid into a marked (premeasured) jar with Dexron III and the Xmission is ready to go and filled to the correct level.  

A few thoughts.