Block plug leak

[IanM]

This morning my '93 Kubota L2550 developed a small water leak at what looks like a freeze protection plug in the block between the exhaust manifold and alternator. The repair manual doesn't mention the plugs (there are three on that side of the block) and they don't show up in any diagram I can find. Has anyone had experience replacing one of these? How difficult is it?

Thanks in advance.
Ian

 

[dougtrr2]

Unless you actually want to try to press in an identical metal plug I think any good auto parts store will have a replacement plug.

Freeze Plug | AutoZone.com

Getting the old one out may be harder than wrenching in the replacement.

Take Care,
Doug in SW IA

 

[KennyV]

Just curious... Do you regularly change your coolant every couple of years?

 

[texasjohn]

never had the problem...maybe radiator stop leak? or water weld?

 

[Buckgnarly]

Knock it out by hitting a corner to flip the plug, then use pliers to pull it out. Be careful though, they can be close to cylinder walls, just do not go whaling on it with the punch and hammer.
They go make install tools that make install easy on hard to reach ones, but if you have a straight shot you can use a socket and extension.
Look at my block heater install post for pics that may help explain it.

 

[IanM]

The tractor has only 1200 hours on it and the coolant's been changed once or twice.

 

[IanM]

Thanks for the help. We have rain here today (finally) and am going to get right on it. As the leak is very small I may try an additive first.

 

[KennyV]

Coolant changed once or twice over 20 years is the problem... The anti rust additives breakdown wit Time, Not operation hours.
It is very likely that the other core plugs are about rusted through, from the inside... You should change ALL of them and inspect all steel components in the system.
Typical coolant should be changed 7 to 10 times in a 20 year period, Long Life coolants 4 change out & flushes.... This should serve as a reminder to others... Just because antifreeze will not freeze, is No indication that it is still good.

 

[Earl Ohl]

Coolant changed once or twice over 20 years is the problem... The anti rust additives breakdown wit Time, Not operation hours.
It is very likely that the other core plugs are about rusted through, from the inside... You should change ALL of them and inspect all steel components in the system.
Typical coolant should be changed 7 to 10 times in a 20 year period, Long Life coolants 4 change out & flushes.... This should serve as a reminder to others... Just because antifreeze will not freeze, is No indication that it is still good.

I agree & want to add STAY AWAY FROM THOSE COOLING SYSTEM SEALERS! They may plug up the leaks fine, but the problem is that they also plug up everything else.

 

[Barneyhunts]

Ian,
I'd check with a Kubota dealer if possible before trying to remove the plug. On newer models the plug needs to be removed with something like a slide hammer, i.e, drill a small hole in the center of the plug, screw in slide hammer attachment and knock it out. The block opening behind the plug may not be a through hole as there may be only a narrow slot behind the plug into the water chamber. Because of this you may not be able to turn the plug. Also, because of the small slot it's important to drill the small hole as close to the center of the plug as possible.

This morning my '93 Kubota L2550 developed a small water leak at what looks like a freeze protection plug in the block between the exhaust manifold and alternator. The repair manual doesn't mention the plugs (there are three on that side of the block) and they don't show up in any diagram I can find. Has anyone had experience replacing one of these? How difficult is it?

Thanks in advance.
Ian

 

[pedalstomper78]

Some good and bad suggestions on here that I'm seeing from my 20+ years of engine experience....
The good....
Replacing the coolant more often. It's like oil. It's not too expensive and is easy maintenance. Every 3 years, mine gets tossed and replaced.
Block plugs are replaced by hitting the edge to knock the plug sideways which will bend it up a bit. Get it taco shaped and pull it out with a pair of pliers. I've seen the slide hammer method done, but I've also seen that do damage to the block.
Another slick idea......why you're replacing the block plug, why not put in a block heater? My tractor has one, my diesel truck has one, even my Subaru has one. It's really like starting a warm engine every time. I see you're in California.....but I'm not sure how warm your part stays. If it drops below 45 degrees and you use the tractor....it's a nice thing to have.

The bad...
Any stop leak is like what Earl said....they do a great job of plugging things up. This includes radiators, heater cores, and thermostats. It's like taking Advil for a stroke....yeah...it'll make the headache go away....but are you really solving the problem?

Here's what you need.
Block plugs: 5 of them to do the whole engine. If you do a block heater, you'll only need 4.
Replacement Parts - L2550DT - L2550 - L2000 Series - L Series Tractor - Kubota

If you're cold and want heat, I found the heater kit for you also.
Accessories - L2550DT - L2550 - L2000 Series - L Series Tractor - Kubota

Here's a video I found on removing them.
[HOW TO] Remove Freeze Plugs - YouTube

WHen you put the new ones in, I usually use a silicon sealer.

 

[IanM]

Thank you all for the excellent advice! I decided against the additive and was able to easily remove the plug. The video was very helpful. I found a brass plug at the local parts store and installed it with the right sized socket and an extension. I filled the radiator with water and ran the tractor up to temperature with no leaks. I'm going to drain and flush the system tomorrow before adding new coolant. I was surprised to see the back of the old plug was shinny--it looked new with the exception of the spot at the left edge that had corroded through (see photo). I was expecting much worse and am now debating if I'll change the rest or not as a couple of the others aren't so easy to get to.

 

[Buckgnarly]

Thank you all for the excellent advice! I decided against the additive and was able to easily remove the plug. The video was very helpful. I found a brass plug at the local parts store and installed it with the right sized socket and an extension. I filled the radiator with water and ran the tractor up to temperature with no leaks. I'm going to drain and flush the system tomorrow before adding new coolant. I was surprised to see the back of the old plug was shinny--it looked new with the exception of the spot at the left edge that had corroded through (see photo). I was expecting much worse and am now debating if I'll change the rest or not as a couple of the others aren't so easy to get to.

Personally I would not bother unless they are leaking, especially if they are in an awkward spot.

 

[pedalstomper78]

Good to hear you got it done. Sometimes .....its not as bad as you think

 

[IanM]

Some good and bad suggestions on here that I'm seeing from my 20+ years of engine experience....
The good....
Replacing the coolant more often. It's like oil. It's not too expensive and is easy maintenance. Every 3 years, mine gets tossed and replaced.
Block plugs are replaced by hitting the edge to knock the plug sideways which will bend it up a bit. Get it taco shaped and pull it out with a pair of pliers. I've seen the slide hammer method done, but I've also seen that do damage to the block.
Another slick idea......why you're replacing the block plug, why not put in a block heater? My tractor has one, my diesel truck has one, even my Subaru has one. It's really like starting a warm engine every time. I see you're in California.....but I'm not sure how warm your part stays. If it drops below 45 degrees and you use the tractor....it's a nice thing to have.

The bad...
Any stop leak is like what Earl said....they do a great job of plugging things up. This includes radiators, heater cores, and thermostats. It's like taking Advil for a stroke....yeah...it'll make the headache go away....but are you really solving the problem?

Here's what you need.
Block plugs: 5 of them to do the whole engine. If you do a block heater, you'll only need 4.
Replacement Parts - L2550DT - L2550 - L2000 Series - L Series Tractor - Kubota

If you're cold and want heat, I found the heater kit for you also.
Accessories - L2550DT - L2550 - L2000 Series - L Series Tractor - Kubota

Here's a video I found on removing them.
[HOW TO] Remove Freeze Plugs - YouTube

WHen you put the new ones in, I usually use a silicon sealer.

Thanks for the suggestion on the block heater and the link. I'm going to put one in before winter. I'm in Northern California and we occasionally get temps clear down into the teens (that's above zero)--I know--nothing like Ohio or Vermont, etc. but still...