B7100 with a slight mechanical issue.

[Grumpy560]

Well got it torn apart again. Hoped my oil leak would have been the rear oil plug in the block but that's not the problem.

When I cleaned the area around the oil plug I could see fresh oil seeping through the engine block just above the oil plug. My first thought was that the block had a crack in the oil journal and this was the end of it for me.

So I'm sitting here trying to figure out what to do and said the heck with this I'm done messing with it and then Wolfman calls me and convinces me to try and repair it.

So, long story short the block is not cracked. What I found instead were 3 pin holes in the casting itself. I found them with a magnifying glass just above the oil fill plug at about the 11 o'clock position. Each time I wiped the area clean I could see oil seep out one of the holes.

I'm going to clean this area up, do a little grinding and slap some JB weld on there. If this does the trick then I'll continue on but if it does not work then this will be the end of it for me.

 

[OldeEnglish]

Well got it torn apart again. Hoped my oil leak would have been the rear oil plug in the block but that's not the problem.

When I cleaned the area around the oil plug I could see fresh oil seeping through the engine block just above the oil plug. My first thought was that the block had a crack in the oil journal and this was the end of it for me.

So I'm sitting here trying to figure out what to do and said the heck with this I'm done messing with it and then Wolfman calls me and convinces me to try and repair
So, long story short the block is not cracked. What I found instead were 3 pin holes in the casting itself. I found them with a magnifying glass just above the oil fill plug at about the 11 o'clock position. Each time I wiped the area clean I could see oil seep out one of the holes.

I'm going to clean this area up, do a little grinding and slap some JB weld on there. If this does the trick then I'll continue on but if it does not work then this will be the end of it for me.

I bet Xpando pipe thread compound would work better for you than JB weld. If you can get it into the holes, it will expand and seal it up like concrete. Made for extreme heat, comes in powder form, just mix a small amount with water to a heavy paint consistency. Try to clean the area it's a paint thinner or acetone to get as much oil off as you can. You can find it at most plumbing supply stores.
Www.xpando.com

I've used it on small holes in sand cast fitings and on cast iron boiler cracks. I've had it hold 250 PSI so it should be plenty stong enough for what you need.
I found it online here, maybe some more searching can find a better price.
http://www.kkes.biz/store.php/KINGO...und_1_lb_can?gclid=CIzclayx1sMCFYI_aQodFZgANg

 

[D2Cat]

Grumpy560, if you use JB Weld or any product that flows some before it dries, I've had good success using a piece of duct tape over the JB Weld to hold it in place.

Clean the metal and put the tape on one side and let it hang down. Dobber the JB Weld on with a 16p nail or something similar and pull the tape up over your material. Doesn't have to be tight, but tight enough to keep the product over the patched area. Tape keeps it where you want it.

 

[Grumpy560]

Thanks guys for the suggestions.

These pics should tell the tale. Look closely and you can see the pin hole and another pic you can see oil seeping out.

I've drained the oil and the engine is on the floor upright with nose down. I just bought some JB weld. I will stop at the plumbing supply and get some Xpando tomorrow.

I'll take a closer look at the block tomorrow and decide where to go from there.

 

[Apogee]

Weird. Man, you're just lucky I guess....

Before I did anything else, I'd be calling Kubota. Talk with someone at corporate and explain the situation. I doubt they'd be willing to do anything but one never knows... This is CLEARLY a manufacturing defect. They might just be willing to take care of you. Yeah it's old and out of warranty, blah, blah, blah, but you bought a brand new crate engine and it's defective - PERIOD. Also mention that you are documenting this restoration thread on the Orange Tractor Talks site and you've love nothing more than to be able to give Kubota credit for stepping up and backing their products.

The other thought that comes to mind is brazing the holes up. A good machine shop would likely have other suggestions like maybe drilling, tapping and installing plugs. It's really hard to see it clearly because the pics are so blurry. My only concern is if the metal happens to be thin in that area. If so, it might not work to drill and tap.

If going the epoxy route, use lots of brake clean and compressed air to clean and dry the area first. You want all of the oil out of there...

That X-Pando dope looks to be very cool stuff. I'm going to order some just to have it around. Read the testimonials, lots of use with oil and at much higher pressures than we're dealing with. Would be perfect to use that with a gasket and the rear plate. It would force the stuff deep into the hole when it expanded if it had nowhere to go out the back of the block.

http://www.xpando.com/testimonials.php

I'd remove the plug on the back and side of the block to see what you see. I'm wondering if you could somehow seal the oil galley in a bit deeper so it would eliminate the oil at the very back of the block. I'm guessing the plug on the side of the block was for machining the passage to the rear main bearing. Obviously one can't block that off. That being said, there is no reason for the oil travel any further towards the back of the block beyond that main bearing passage. Hence I'm wondering if one could machine an aluminum plug that would fit from the rear that would be pressed in by tightening the threaded plug. I would think it would "dry up" any oil back where the casting shift occurred. Just an idea... You'd have to look carefully to make sure there aren't any other passages that you'd be blocking off. You ought to be able to see all of them with a flashlight once the plugs are out.

Finally one last thought is to machine a 1/2" thick bell housing adapter plate, mill it flat and gasket the entire back of the block. You would need to make sure there was enough clutch adjustment for the increase in depth. I mention making a new plate out of 1/2" for strength. It would be more likely to maintain its flatness once tightened up.

Perhaps consider gasketing the entire back of the block no matter what. It would add additional support to whatever you use to plug the holes.

What a PITA!

Sorry man, I know this is discouraging. Don't give up!

Steve

PS - If your camera has a macro setting it would be helpful here.

PSS - I see D950 blocks going through eBay all of the time. There are 3 listed right now. But, we're not there yet.

 

[North Idaho Wolfman]

Looking at the pictures and comparing it to the block I have here, I'm afraid that it's actually cracked and not a casting flaw.
It looks like there is a dent on the mounting pad directly over the side plug??? I could be wrong.
Being that it is that close to the edge of the block, I remove my earlier statement that JB weld would be the best choice, I now think that brazing it would be a way better option!
Like I said to you once you start to heat it with a torch, you will see any traveling cracks or holes and they will be better repaired.
Just so I know I'm understanding things, the leak is at the spot in yellow right? If so I'm worried that it's cracked along the line in purple.
For others notes, the hole or crack is no bigger than a sharp pencil point, and the holes to the right and left are threaded plugs that lead to the oil galley for the crank shaft that were used when the machined the block.

 

[Apogee]

Steve,

One other thing - in this case I would STRONGLY recommend you take the engine to a welder that works with cast iron on a fairly regular basis or at least has knowledge about it. This is not something you want to try using a little propane torch. Sounds like you work for a pretty good machine shop so perhaps one of the guys who does welding work in the shop would know how to properly handle it.

To do it right, the holes need to be opened up, the area preheated hot, hot, brazed, then slowly cooled down. To do the preheating correctly, one needs a decent size rosebud. It's actually a fairly easy repair, it just needs to be done by someone who knows what they're doing.

DO NOT let them weld this with nickle rod or try to tig it. Too much heat concentration in the weld zone and it will likely cause other cracks. Plus the weld will shrink more quickly than the cast iron when cooling.

If it is a crack as Shawn mentioned, then holes need to be drilled at either end of the crack to stop it from running further. If it extends from plug hole to plug hole, then don't worry about it as the plug holes will act as your "stops". He's completely correct that it will show once heated if it's a crack. Based on the other pinholes, I think the casing has porosity in that area and it's a defect. In either case, once heated good and hot, the bronze will follow the cracks or holes and you should be good to go. Bronze is plenty strong so no worries there, and unlike epoxy, the oil from the leak won't affect bonding.

Again, I'd make a call to Kubota before I did anything else. It likely won't go anywhere, but it can't hurt to ask. Need to get to someone fairly high up like VP of sales or someone like that. They may be willing to send a new block, one never knows.

Also, you need to decide which direction you're going to try. If you attempt an epoxy repair and it fails, then you have a mess from a welding standpoint. If it were mine it would get brazed. Food for thought...

Finally, those plugs should be removed or at least loosened while the heating taking place. They are a tapered fit and one doesn't want them expanding at a different rate than the cast iron and cracking the block any worse.

Again, don't get discouraged.

Best,

Steve

 

[OldeEnglish]

If it was me I would try the Xpando before the epoxy. If it doesn't work the epoxy will stick to the Xpando. I've never seen cast brazed but you guys definitely have me interested and motors are a whole different game than what I'm used to.

Xpando is a good product but it's not an every day pipe dope. I only use it on something I don't want any chance of a leak like iron pipe larger than 2 1/2" that will never have to come apart. The only way to loosen and remove an Xpando joint is to beat the death out of it with a hammer at the same time your wrenching on the fitting. Just be aware where you use it because if you need to get it apart you'll wish you never used it!

Grumpy, if you end up using the Xpando..... Let it setup for at least 24hrs. If it's cold in your shop....point a halogen light at it to keep it warm while it sets up. It just needs to be warm not HOT. You can speed up the chemical reaction by applying heat from a torch but I'm not a fan of doing that (it does work in a pinch).

Good luck! You've done too nice of a job to give up!

 

[Apogee]

Steve,

This guy knows what he's doing.

The brazing job on that piece of bronze is very ugly but keep in mind that is very thick material and that material is a bitch to work with. It takes a TON of heat to work something like that. Very tough to do on something that thick. Notice his brazing job after grinding. No pinholes or imperfections.

The prep, pre and post heat on the cast iron is exactly the proper way to do it imho. In your case, I'd use a rosebud because the block will dissipate a lot of the heat away. Hence one needs a bigger flame. Other than that, the procedure is identical. Lots of heat and slow, controlled cooling.

If you want to skip, the cast starts at 3:58:
https://www.youtube.com/watch?v=117Q9odITF8

Cast starts at 2:20:
https://www.youtube.com/watch?v=U8GHsC5gk6E

Figured I'd link these so you'd know the way the repair should be done. I figure after seeing these you will have a feel for what it takes and will be able to chat with the welder beforehand to figure out if he knows what he's doing or not.

Steve

 

[MagKarl]

Brazing would be my suggestion as well. This is the time to pursue a permanent repair.

 

[Grumpy560]

Thanks everyone for the great advice here. This is something I've never had to deal with before and I really don't want to make any quick moves on a repair that could break this projects continuation if it fails to work.

That said, I can positively tell y'all now that the block is NOT cracked. My machinist from work stopped by this evening with his friend from our local machine shop, that was a surprise visit as I was not expecting that.

They used some sort of scope, heat gun and some kind of chemical that they brushed on the area around the oil plug. I was assured right then that it was not cracked. They called it a cold casting flaw whatever that means, I don't know about that kind of stuff.

Yes it can be fixed and YES it will be fixed and NO I'm not the one who's going to be doing the fixing here, I'm gonna play this one smart and let the professionals who do this every day fix it.

I'm going to drop ithe engine off at the machine shop Thursday afternoon and leave it there. I didn't ask how long it would take to repair it because I didn't want to sound like I was being pushy in any way.

I'll update again when I get the engine back.

 

[Apogee]

Excellent!

 

[pendoreille]

Grumpy, appreciate the time you have put into keeping this thread alive and the time in to your tractor issue, I have learned a lot.

 

[ShaunRH]

good thing you are letting it be professionally fixed. I would have brazed it or Stainless Mig spot welded it. Muggy Weld also makes a good cast iron brazing rod that can handle the fix. I'm sure the pros will do the fix right (Drill the holes and patch or something along those lines)

 

[Lil Foot]

I've had excellent results repairing porosity & cracks in castings with a method similar to Lock-N-Stitch:
https://www.youtube.com/watch?v=Pq0wfU4ZaKk
Only difference being we were doing it decades before you could buy Lock-N-Stitch pins, so we made our own "pins" out of suitable material, drove them into tapered threaded holes until they seized, and cut/ground them flush. Sometimes we used a sealant, sometimes we locked them in with a small pin drilled & installed at the thread interface.
I look forward to seeing more on this repair, keep up the great thread!

 

[Dan_R_42]

I've had excellent results repairing porosity & cracks in castings with a method similar to Lock-N-Stitch:
https://www.youtube.com/watch?v=Pq0wfU4ZaKk

Lil Foot, thanks for posting the link!!! Very informative. Interesting process.

 

[Grumpy560]

I dropped off the engine at the machine shop this afternoon. They won't have time to get started on it till early next week. I told him that was fine, just give me a call when its done and I left.

Now, I still need to find some parts to finish up. I need the correct oil check dip stick, a new air filter, new temp sender unit, tachometer cable and a side mount battery box.

Wolfman, would you by any chance have a part # for the oil check dip stick?

Well that's about all I have for now. I'll update again when I get the engine back and everything put together again.

 

[North Idaho Wolfman]

That would be P/N 15371-36410 $10.09
http://www.colemanequip.com/Parts_Detail.asp?partID=4999

 

[Woodswalker]

That's good news on the oil leak issue and fix underway. I have a B7100, circa '77, that is still going strong. Can just imagine how it would handle with 5 or so more horses like you will have. You're doing a great thread, we are all learning much.

 

[Grumpy560]

Alrighty, I've uploaded a couple of videos of the B7100 on YouTube. The first one is about 5 minutes long and was taken shortly after I bought it. Nothing much to see except the sound of an engine screaming for help.

The second video is only a few seconds because I couldn't run the engine too long at one time, no coolant. This was about the 5th time it was run and is also where I discovered the oil leak.

I'll take more video when I get the engine back from the machine shop.