Injector Seat Damaged: Best way forward?

[CaptBeardilocks]

I am currently refreshing my 1HDT before swapping it into my FZJ80. I pulled the injectors and sent them out to be rebuilt. Upon pulling the copper seat washer out of #2 I found that the previous idiot that was in here had some trouble getting that washer out and marred up the seat in the head pretty bad.

I drove this motor for a while before I pulled it and it ran great. Compression was good and leakdown was correct. I did have a hard time pulling the injector on #2 and now I’m guessing that the washer was leaking ever so slightly and maybe coked up that injector seat enough to make it come out hard.

The question now is how to proceed. Is there a method to clean that surface up a bit with the head on? The copper washer was sealed on there pretty well like this before, so I’m hoping a very little smoothing out could make it function fine. Best way to do that?

Also: how tight are the tolerances there? Is a thicker copper washer an option?

 

[Outono]

You can just buy new ones, which is probably the easiest / best thing to do. If your 1HD-T is pre-1992, then the part # is: 1117617010

 

[CaptBeardilocks]

You can just buy new ones, which is probably the easiest / best thing to do. If your 1HD-T is pre-1992, then the part # is: 1117617010

The copper seat washers have been removed. The damage you see is in the head with the copper seats removed.

 

[Outono]

The copper seat washers have been removed. The damage you see is in the head with the copper sears removed.

Oh my bad, I should have looked more carefully. Yikes! Sorry to see that...

 

[roscoFJ73]

I would get advice from a machinist. You might be able to fill in the gouges with some kind of heat resistant filler like epoxy Then put a new washer on top of that.
Another way might to fill the hole with tightly stuffed cotton/ wooden dowel. When the gouges are ground out, vacuum the filings and pull the cotton out.
As long as nothing falls down there you should be ok

 

[wapitimud]

I don't like the idea of epoxy here at all. This isn't a JB weld fix..

I would get the head off, and over to a machine shop for a proper fix. The head was manmade, so man should be able to repair it properly.

There may be proper machine shop inserts, etc in that size that would be a longterm fix. It probably isn't their first rodeo.

 

[CaptBeardilocks]

Yeah, I think I would avoid epoxy in the pre-chambers. But I'd also really love to avoid taking the head off without another reason (head gasket or time to do the valves). Engine was running great like this before I discovered it. I would just like to avoid it becoming a problem in the future as well. Having my cake and eating it too, right? Lol.

Best idea I've had so far is to clean it up as much as possible so there's no high spots and then paint in some of that copper head gasket spray and drop the copper seat washer on top of that and hope that seals it up tight. I'm sure someday in the future I'll get the valves done and possibly rebuild the motor. But at a young 195k miles and running great I'm not keen on a (very expensive) preventative rebuild here.

Any other ideas? Anyone have any practical knowledge about inserts or repairability of the pre-chambers in the first place?

Thanks!

 

[roscoFJ73]

Well try some exhaust sealant. It not under much pressure in there. You just need to seal it off so no gases can get under the washer. Its obviously gone a fair while with nothing in there and hasn't damaged anything.

 

[gerg]

Just because it’s damaged doesn’t mean it’s a problem. If your injector shows no damage I would be hesitant to alter it too much. Taking down the proud spots would be a good idea but not sure if that would be easy to do In a uniform way. I’d rather have proud areas to imbed into a soft washer as oppose to low areas which wouldn’t seal. Only real concern id have would be with Interfering with injector spray pattern in the cylinder. I might stick a bore scope down there and check for piston cracking on the bowl edges. It might be lifting the injector up enough to heat up the bowl edges.
I remember a good saying. “The greatest source of problems are solutions....” Go easy.

 

[CaptBeardilocks]

Only real concern id have would be with Interfering with injector spray pattern in the cylinder. I might stick a bore scope down there and check for piston cracking on the bowl edges. It might be lifting the injector up enough to heat up the bowl edges.

Looking at it closely I would say that it's possible someone *might* have already tried to flatten it out or sand it down. So I might be more concerned with the injector sitting in too far. I have to figure out a way to accurately measure the depth.

 

[gerg]

Pretty tight but I venture the bottom end of a vernier caliper could Fit down there and sit on the upper step and measure down to the lower seat.

 

[Tim Collier]

Thanks for posting this thread! I’m in Stuttgart, Germany and I am in the middle of a injector service. My HDJ80 is at 333,000 or so kilometers, and I think that this the first injector service. Diesel Center Bieberach has refurbished the injectors, and my feedback is that they were completely crapped out, springs barely working. And, the copper washers were pretty much welded on to the seats. I began to remove them last Friday, and after sitting in Liquimoly injector removal fluid, they still had to be rather forcibly extracted, with just about removal tool you could think of. Unfortunately, the removal has left some gashes on the injector seat. Today, my mechanic pal is going to ask his old car restoring buddy to look at the valve seats so that we can proceed. I’ll post some pics of the seats later on today...

 

[Tim Collier]

The next step was to use a seat re-surfacing tool - looks like a rod with a round set of teeth and a portrdung post at the bottom, also with a 19mm socket head on the back. We took a light air pressure driven right angle socket wrench and cleaned down the seats until the nicks had receded, leaving clean medal around the outer circumference of the injector seat. Gerhard reckoned that rhe seats would now marry up to the copper bottom seals tightly. Apologies, I don, t hav e agood after picture, but here are my injector seats after we removed the copper. We also found it easier to remove the hood and heater valve to get at the #6 cylinder, backed up to the firewall as it is. After a day or two of driving, truckis definitely quieter, less tailpipe emissions, and less sluggish. I will see, after a fill up, how the mileage shakes out.

 

[ManojlO]

I am currently refreshing my 1HDT before swapping it into my FZJ80. I pulled the injectors and sent them out to be rebuilt. Upon pulling the copper seat washer out of #2 I found that the previous idiot that was in here had some trouble getting that washer out and marred up the seat in the head pretty bad.

I drove this motor for a while before I pulled it and it ran great. Compression was good and leakdown was correct. I did have a hard time pulling the injector on #2 and now I’m guessing that the washer was leaking ever so slightly and maybe coked up that injector seat enough to make it come out hard.

The question now is how to proceed. Is there a method to clean that surface up a bit with the head on? The copper washer was sealed on there pretty well like this before, so I’m hoping a very little smoothing out could make it function fine. Best way to do that?

Also: how tight are the tolerances there? Is a thicker copper washer an option?

View attachment 2480644

View attachment 2480645

Hello, I have the same problem, did u manage to repair it?

 

[veiloctane]

i have the same issue on mine i believe it is cylinder 4 i picked up a 17pcs reamer from amazon worked great

Amazon.ca

 

[sodafeld1]

I damaged the higher seat myself on my 2h working in the bright sun and not being able to see down the hole properly thinking the brass sleeve washer was stuck, I put a large tapper to pull what I perceived to be a stuck brass washer out which wasn't there. So I chipped the edge of the head upper seat. It did my head in a bit. Frigged around with creating thicker soft shims to compensate for the chip. Spoke to an experienced diesel mechanic I liked. He reassured me the lower is the most important seal. Which is what you are facing.

I agree with the above upon just gently smoothing the high spots and vacuum the seat after with hoses that fit well. Dowel and emery perhaps or sometimes I use sintered diamond grinders to minimise residual..or the tungsten reamer mentioned. Then try to blow any residual out with lots of compressed air.

The u cup crush seals are quite soft. By the looks of the scar it does not reach the edges and a fair bit of torque is placed upon those seats. So you may be ok. Bet it has been done before that sort of damage. Perhaps keep an eye on it and service your injectors a little more frequently to observe coking or leaking.

I was surprised when I thought it was the end of my head, imagining the chip of head scarring my cylinders. But I got a best of 9l/100km for around least 80k kms on the engine so certainly cannot complain. She still is pretty good at 10-11l per 100km always with heavy loads. I think I need to do the rear main seal, little leakage, but putting it off until I have to do the clutch. There is always something.

I have not read the best reports on the hdt, but diesels in general are pretty robust, simple and forgiving. Could just run it whilst looking for another head if you really like what you have.

 

[veiloctane]

I ran mine for a couple of years 100K Km no leaks no excessive carbon buildup around the injector mating surface. So I think the copper washers really help seal it up. I just got the reamer just because and just incase.