Kubota B6100 - radiator issue

[clippy]

Hi everyone. Here's my first request for info/opinion on this great site. I bought a new to me B6100 a couple months ago. It's my first ever tractor.



I used it for a few hours since then and noticed the tractor ran a bit hot. That made me make some time to do some maintenance on the tractor: change fluids and filters, clean up radiator and replace hoses, etc. Here's what my radiator looked like:



And here's what the coolant looked like when I drained it:



It looked even worse when I disconnected the lower radiator hose. A lot of rusty fluid came out. Here's where the upper radiator hose joins engine block:



The lower radiator hose has just about the same amount of rusty fluid left coating it.

Is there anything extra I should do besides flushing everything out with water to clean out radiator and engine block? Any other tips to get all this rust removed and the radiator running well?

Thanks in advance.

 

[MagKarl]

Welcome! That looks like it's in really nice shape.

First, how hot is hot, where and how are you measuring temperature?

Some of the smaller engines don't have a water pump and rely on thermosiphon to move the coolant. It's very important to have a good clean radiator, inside and out.

The coolant itself doesn't look bad to me but good of you to change it. I don't think some rusty muck is too out of the ordinary in my experience, but maybe my coolant maintenance frequency is too lax.

 

[Tooljunkie]

If it has a thermostat, pull it out for flushing. I had a head gasket go, and used simple green to flush the block. It cleaned it quite well.
Could use heavy duty rad flush, but i prefer not to put anything corrosive into my cooling systems.
A couple good water rinses and refill with a good quality coolant. I mix mine on the strong side as you dont know how much water is left in the block. Dont forget to reinstall thermostat. Critical for proper operation of cooling system.

 

[clippy]

Thanks MagKarl and Tooljunkie. The tractor is in pretty good shape except for the radiator and a leak on right hand side of engine, possibly hydraulic fluid.

"Hot" is just my inexperienced opinion. Like I said, its my first tractor. No temperature gauge or thermostat on the B6100. I was pretty worried when I saw all the rusty water. And forgot to say when I bought the tractor the radiator had no overflow hose and that radiator was coated in a rusty residue, as if it blew out after overheating.

Besides a coolant, is there any sort of rust inhibitor I should add?

 

[MagKarl]

This time of year I'd probably refill with distilled water and run it a while, then drain/flush again. Doing that a couple times will help flush out the loose rust. When you're satisfied with how clean the water looks, then refill with coolant. I do this on my own rigs, and have also used Prestone radiator flush. I can't really say if the Prestone did anything good or bad.

 

[meanjean]

I experienced a very similar situation a few years back. I flushed the system like the others have suggested. I also used a zip tie and individually cleaned each and every fin by pushing the zip tie thru. It took me a week of Sundays but it was nice and clean. I have since elected to have the radiator re-cored for $300. I'm getting it back tomorrow.

 

[clippy]

Thanks MagKarl and meanjean.

I had the same idea about running with distilled water a couple times to clean out some more before finally filling with coolant.

Re cleaning the fins I'll use an air compressor or pressure washer. Not sure the othet half/better half could stand me taking so much time.

 

[85Hokie]

Thanks MagKarl and meanjean.

I had the same idea about running with distilled water a couple times to clean out some more before finally filling with coolant.

Re cleaning the fins I'll use an air compressor or pressure washer. Not sure the othet half/better half could stand me taking so much time.

cleaning out with white vinegar can help clean out all that crud too, cheap and very effective. Do vinegar water wash, make to get it hot, drain, water only, drain, then go back with your 50-50. Some recommend running baking soda back through after the vinegar. Vinegar is mild BUT if left in a while will eat up the works.

 

[Lil Foot]

air compressor or pressure washer. /QUOTE]
I have no concern about the compressor, but I'm pretty sure my pressure washer would destroy the radiator in my B7100......just saying.....

 

[meanjean]

Be careful not to bend the fins with compressed air/pressure washer.

Got mine back today and it looks great!
$350 to recore.

 

[clippy]

Thanks for the heads up re bending the fins. Will probably use the air compressor with the psi set pretty low. Your radiator looks nice. Have found out where the one radiator shop near me is located in case I need to do the same.

 

[North Idaho Wolfman]

Clippy,
DO NOT use a pressure washer to clean the radiator fins unless you have an adjustable pressure model as it takes very little force to damage both the fins and the cores, just a water hose will flush everything out.

One observation you need a shorter top link, I bet you have a standard length top link you need a 13" or 9" Body top link, that will allow you to raise the implements properly.

Note: Late post: wrote it before, but forgot to send.

 

[clippy]

Thanks for that wolfman. Not a good picture of the rear to spot that. I'll have to check the top link next week; I'm on vacation at the moment. Will check that out when I get home. I didn't think it raised and lowered the tiller very well. This might be why.

 

[clippy]

I finally got around to flushing the inside of the radiator and cleaning the outside/fins of the radiator and replacing the lower and upper radiator hoses. Looking pretty good now. And with all the gunk that came out, it should run better. Let's hope. I'm currently only running it with 100% water. Will do another flush after a couple of hours running before filling with 50/50 water/coolant.

I did find what appeared to be half of a circular metal clip when flushing out the engine block. It was quite corroded. Not sure how that got in there.

I have also noted that the radiator doesn't have the overflow hose. So will get that the next time I place an order for parts, or stop by the local dealer (over 1 hours drive away.)

 

[mrmr56]

Bobbieboo, Is this your brother in law in Kansas who can repair radiators? Sounds fishy to me.

 

[100 td]

With 11 duplicate posts he's either on commission or runs the shop. I think the forum can do without this, perhaps a mod will intervene?

 

[Cstocountry]

Hi all
I have a question regarding filling once flushed, does the cooling system need to be bled or as some may call it burp? I'm concerned about air pockets after filling.
Thanks in advance

 

[North Idaho Wolfman]

Hi all
I have a question regarding filling once flushed, does the cooling system need to be bled or as some may call it burp? I'm concerned about air pockets after filling.
Thanks in advance

No air pockets in that model as there is no water pump or thermostat to trap air.

 

[85Hokie]

Hi all
I have a question regarding filling once flushed, does the cooling system need to be bled or as some may call it burp? I'm concerned about air pockets after filling.
Thanks in advance

If the system was completely drained, radiator pulled, there might be some air there - but it will not be there long, as NIW said, no pump or real restrictions to create a pocket. One thing to be careful, make sure to fill ALL the way up - water should be at the top of the plates about 1" down from the neck/cap. Too much water and it will/can kick out some. Too little water and it will not flow correctly due to the air at the top of the radiator.

 

[shane772]

Had to clean mine out recently too


I carefully used my air compressor. It came pretty clean.