# IH 674 1977 Injector Seals



## Casiat (Jul 5, 2011)

Hi there,

Having had a clean of the fuel system after a blockage I have an issue in refitting the injectors.

The old seals were all broken or perished so I have replaced them with the only pattern parts available but as you can see they sit so proud they injectors simply won't go back in sleeves.

There appear 2 types of injector and most Google pictures show a different one from mine (possibly with a heat shield?).

I'm looking for any help on this... Perhaps I need to find some bespoke seals?

Thanks in advance.

Simon
Attleborough, Norfolk, UK


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## pogobill (Jan 31, 2012)

Have you determined which injectors you need? Apparently there are nozzles for C.A.V. injection and for Bosch injection, according to the Case IH Parts diagrams.


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## Fedup (Feb 25, 2014)

If you're referring to what looks to be an O ring in your photo, the position shown is not where it's supposed to be. Nothing actually goes there. The O ring (or possibly a cork seal originally) would just slide up further on the injector body and merely rest on the cylinder head. It's not meant to be much of a seal anyway, it just helps keep dirt and other debris from filtering down into the space between the injector body and the bore it fits into. The actual sealing takes place at the bottom where the rounded portion of the nozzle retainer nut meets the copper sleeve in cylinder head.


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## Casiat (Jul 5, 2011)

PogoBill/Fed up... Thank you both.

These are the original Injector's and as you say Fed up, this 'groove' is actually where it seperates and looking closely, you can see the top of the thread.

I've now managed to reseat the injectors and it soon started up.

However.. Despite running now, which it didn't do before I started fiddling, it looks like it's only going on 3 cylinders so I assume I've dislodged the original blockage down towards the nozzles...

Onwards and upwards.

Thanks again.

Simon


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## Fedup (Feb 25, 2014)

I'm not sure what you had going on that you refer to as a "blockage", nor how "cleaning" of the fuel system involved removal of the injectors to begin with. There are a few possibilities for a miss on one cylinder now that wasn't there before. You should loosen the injector lines one at a time with the engine at low RPM to determine the offending cylinder then investigate that particular injector.


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## Casiat (Jul 5, 2011)

It was very much an error. I needed to replace the return lines as two were perished and leaking badly.

All went well until it started 'hunting' with a blockage. Despite efforts I couldn't clear this.

Having never removed an injector before, I 'investigated' by removing the clamp but it was solid so decided not to pursue this angle.

Sadly I didn't put the clamp back on when I started up again and it blew out...
So I decided to remove all of them. 2 look in good nick but 2 were badly burnt, I assume from perished seals allow dirt down over many years.

I then got the new seals and we are where we started..... .

Despite the above issues I am moderately competent so will have a go at tracing dodgy injector....

I assume you mean loosen main line rather than return line...

Thanks again.

Simon


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## Casiat (Jul 5, 2011)

Just a quick update... I removed all 4 injector's and cleaned the nozzles, a few of which were partially blocked.

The old girl fired up fine and was running smoothly (for the first time since I started the job) until she slowly died again. However I traced this to grotty fuel filters so we are now all good to go.

Thanks to everyone who helped. 

Simon


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