Question for Diesel Techs about replacing common rail injector seals..?

[Rico.]

Hey Chaps...

I have been tasked with replacing the injector seals on my Brother-in-Law's little van.
He was told that the exhaust manifold was leaking, but after he brought it over for me
to fix that, it was obvious that it was one injector that was leaking and the manifold was
perfect.

Now, I'm a competent DIY mechanic, but lack experience... However provided the
injector isn't stuck inside bore the job looks straight forward enough. I just have a couple
of questions to make sure I do the best job I can....


1. What is the best way to clean the cabon and **** off the injector that was leaking..?

I have Carb cleaner and brake cleaner and Kerosene at my disposal, also brass and plastic
brushes, a dremel with brass wheel... are any or all of these safe to use..?


2. Do I need to lube the new o-ring when fitting to the injector..?

I have motor oil, gear oil, Automatic transmission fluid, vaseline... or do they go on dry.


3. Would you replace the seals on all of the injectors (There is only 4 on this engine) or
just the one that was leaking..? I have new seals for all 4 injectors already.


Thanks very much in advance for your expertise.....

 

[NorthSea92]

First and foremost, what kind of van is it? Is it the seal that goes where the injector seats on the cyinder head?

Depending on how badly it is leaking the injector could well be knackered and need replacing and it will probably be a copper washer. Make sure you clean the injector seat, if you spray lots of brake cleaner in the hole then it will probably knock when you first start it up and use a light smear of rubber grease to hold the new seal on the injector, do not get any on the end where the fuel comes out. If you do decide to replace all four seals mark the injector and refit them in the order they came out.

 

[MBfreak]

The common rail injectors are sealed off towards the combustion chamber with a copper gasket. Sealing is achieved by pressing the injector against the copper washer and then against the head.
If this seal has been leaking there is a risk that the sealing surface in the head is damaged. In my expereinece , it is best to ream the head sealing surface with the appropriate special tool, which is quite expensive.

Best regards

Ola

 

[blackedout12v]

Some CR injectors use cross tubes that feed fuel from the rail to the side of the injector, not sure how yours is set up but this could be a potential leak source

 

[Rico.]

I really appreciate the responses.... However all the concerns you have put forward I am
already aware of.

I only needed guidance on cleaning the carbon off of the injector and if
carb clean and a brass wire brush is safe to use, and if i should lube the rubber o-ring that
fits towards the top of the injector.

The copper sealing washers, potential head issues and high pressure fuel line issues
I am aware of, but I appreciate the heads up.

 

[Olafur]

Brass wire wheel is fine on injectors, should clean them up right away.
lube the o-ring, I would just use engine oil.
Oh, and I would do all four!

 

[colin39]

Remove injector , should be easy as its blowing by, clean airline blow all **** away , and set washer surface with appropriate cutter, and Re-install injector. Simples see.

 

[Olafur]

Isuzu:
Notice the difference between the injectors.

 

[colin39]

Isuzu:
Notice the difference between the injectors.

Other than blowing by like bar stewart? Dunno enilighten/educate me?
Not being sarcastic, too many vodkas, stuggling to focus. Soz

 

[Olafur]

Other than blowing by like bar stewart? Dunno enilighten/educate me?
Not being sarcastic, too many vodkas, stuggling to focus. Soz

Just showing the dirt build up from blow by. This was a minor one, injector wasn't even stuck.
Cheers!

 

[Dirty Diesels]

Hey Chaps...

I have been tasked with replacing the injector seals on my Brother-in-Law's little van.
He was told that the exhaust manifold was leaking, but after he brought it over for me
to fix that, it was obvious that it was one injector that was leaking and the manifold was
perfect.

Now, I'm a competent DIY mechanic, but lack experience... However provided the
injector isn't stuck inside bore the job looks straight forward enough. I just have a couple
of questions to make sure I do the best job I can....


1. What is the best way to clean the cabon and **** off the injector that was leaking..?

I have Carb cleaner and brake cleaner and Kerosene at my disposal, also brass and plastic
brushes, a dremel with brass wheel... are any or all of these safe to use..?


2. Do I need to lube the new o-ring when fitting to the injector..?

I have motor oil, gear oil, Automatic transmission fluid, vaseline... or do they go on dry.


3. Would you replace the seals on all of the injectors (There is only 4 on this engine) or
just the one that was leaking..? I have new seals for all 4 injectors already.


Thanks very much in advance for your expertise.....

Use a wire brush on a drill to remove all the gunked up residue off of them & lube the new seal with a little oil & also be sure that the injector seats back down correctly & the fuel unions line up correctly, the thing with most common rail injectors is to get them back in the same position otherwise the fuel unions wont fit proper & you will be wondering why. You will be better off doing all four, saves the hassle of coming back to do the others later.

 

[Rico.]

Brass wire wheel is fine on injectors, should clean them up right away.
lube the o-ring, I would just use engine oil.
Oh, and I would do all four!

Use a wire brush on a drill to remove all the gunked up residue off of them & lube the new seal with a little oil & also be sure that the injector seats back down correctly & the fuel unions line up correctly, the thing with most common rail injectors is to get them back in the same position otherwise the fuel unions wont fit proper & you will be wondering why. You will be better off doing all four, saves the hassle of coming back to do the others later.

Thanks Chaps.... Big help and Much appreciated..

 

[Olafur]

Ps
I don't think It needs to be mentioned, but still.
Don't do anything with the tip point (nozzle), at least no wire wheels there. And unlike me (see pic) closing off the inlet to the injector right away before cleaning - is a good idea to avoid any debris entering.

Have fun!

 

[Rico.]

Ps
I don't think It needs to be mentioned, but still.
Don't do anything with the tip point (nozzle), at least no wire wheels there. And unlike me (see pic) closing off the inlet to the injector right away before cleaning - is a good idea to avoid any debris entering.

Have fun!

Anything useful is always worth mentioning... I tend to use the finger cut off a latex glove to
protect ports from debris... Works really well... and I was only planning on cleaning the
injector as far down as where the copper washer seats, and no further... Cheers.

 

[ncautoshop]

I use a couple of methods. If it's not bad a scotchbrite pad and some carb cleaner will do the trick. An ultrasonic cleaner also does a nice job. I wouldn't be gutsy enough to hit a common rail nozzle with a wire wheel but that's just me. I use engine oil or silglyde on orings.

Sent from my SCH-I605 using Tapatalk

 

[stikman56]

I have always used silicone grease on injector seals as Detriot's states to do on their's. I feel it's a little better protection against the possibility of tearing up a seal on installation. Hasn't fail me yet, anyway.

 

[Olafur]

Just for fun, here is a pic from the same engine as the injector pic above:
Nothing wrong, just a small blow by causes carbon build up in the chamber... and the valves and seats didn't look to good either.

 

[[email protected]]

1. Hand clean carbon off using a Brass Brush. No powered brush/wheels, etc. esp on
injector tip lest you want to damage or block the holes. Wash off with diesel or
kerosene.
2. Lube seals with Rubber Lubricant. If you don't have one, use rubber grease. No
lubricant on copper washers/seals if any.
3. Clean hole on head before re-installing injectors.

 

[Rico.]

Just a quick follow up.....

I did all the injectors and a full service over the weekend and the job went great.
The leaky injector was a bit stuck, but after some wiggling and jiggling got it out ok.

I just took my time, cleaned everything really well and it went back together very
nicely... Started her up and after a couple of seconds purred like a kitten. I'm
delighted with the result.

So thanks to everyone for the hints and tips... The GJ is a little gold mine,
and all you chaps are little chunks of Gold..... very very much appreciated.

 

[Motor-Mechanic]

Late to the party on this one! did you replace the fuel lines between accumulator and injectors? they're single use only and should always be replaced if disconnected.

 

[Rico.]

Late to the party on this one! did you replace the fuel lines between accumulator and injectors? they're single use only and should always be replaced if disconnected.

You are of course correct....

However I researched a ton on this job, and everyone who had done it on various
forums did not replace the fuel lines and were sucsessful... The only real horror stories
were injectors that were siezed in the head.

Even the manual suggests to only replace the lines if you have a leak after tightening
the union nuts to the correct torque. I will keep an eye on it, but so far so good.

 

[Dirty Diesels]

Just a quick follow up.....

I did all the injectors and a full service over the weekend and the job went great.
The leaky injector was a bit stuck, but after some wiggling and jiggling got it out ok.

I just took my time, cleaned everything really well and it went back together very
nicely... Started her up and after a couple of seconds purred like a kitten. I'm
delighted with the result.

So thanks to everyone for the hints and tips... The GJ is a little gold mine,
and all you chaps are little chunks of Gold..... very very much appreciated.

Glad to hear you got the job done.

 

[stikman56]

You are of course correct....

However I researched a ton on this job, and everyone who had done it on various
forums did not replace the fuel lines and were sucsessful... The only real horror stories
were injectors that were siezed in the head.

Even the manual suggests to only replace the lines if you have a leak after tightening
the union nuts to the correct torque. I will keep an eye on it, but so far so good.

Glad to hear that went well. It's always a great feeling when you fire them up and they just purr.

 

[Rico.]

Glad to hear you got the job done.

Glad to hear that went well. It's always a great feeling when you fire them up and they just purr.

I don't know if anyone is interested ( I probably wouldn't be )

However it's now been about 6 weeks after I did the job and the engine is
still purring away, with no leaks or any problems... So I'm officially calling this
job a Win.

....and a final Thanks, once again, to everyone who helped.
I'm Upgrading you from Gold Chunks to Diamonds..... Cheers.