Injector Hold Down

Kaktusjaque

Kaktusjaque

2002 Freightliner
Does the Injector hold down apply a downward force pushing the injector down to create a seal?

I am wondering this question. When I first removed my injector, I had to apply a slight force with a pry bar to get it out. Not much, just a bit more effort than if I tried to remove it by hand. Putting my injector back in, requires no force at all. I can even take it back out with two fingers, i.e. no force needed at all to remove it. After putting everything back together, I am getting exhaust and fuel blow back from around the injector. A new copper o ring was used when replacing too. Just wondering why my injector is not getting a good seal.
 
wefixscratchedglass

wefixscratchedglass

Member
Kaktusjaque said:
Does the Injector hold down apply a downward force pushing the injector down to create a seal?

I am wondering this question. When I first removed my injector, I had to apply a slight force with a pry bar to get it out. Not much, just a bit more effort than if I tried to remove it by hand. Putting my injector back in, requires no force at all. I can even take it back out with two fingers, i.e. no force needed at all to remove it. After putting everything back together, I am getting exhaust and fuel blow back from around the injector. A new copper o ring was used when replacing too. Just wondering why my injector is not getting a good seal.
Click to expand...
The injector seats must be cleaned and possibly milled to remove any surface issues that may not allow a good seal. Yes bolt needs to be properly torqued. Everything should be clean and smooth.

Sent from my SM-G860P using Tapatalk
 
2

220629

Well-known member
Kaktusjaque said:
Does the Injector hold down apply a downward force pushing the injector down to create a seal?
Click to expand...
Yes. There is a fulcrum point on the injector hold down claw. The injector bolt provides the downward force on the injector body to compress against the copper seal.

Kaktusjaque said:
When I first removed my injector, I had to apply a slight force with a pry bar to get it out. Not much, just a bit more effort than if I tried to remove it by hand.
Click to expand...
That is normal. the partially burned leaking products of combustion form "Black Death" which fills in the close tolerance space around the injector. The build up sticks the injector body in the injector well.

Kaktusjaque said:
Putting my injector back in, requires no force at all. I can even take it back out with two fingers, i.e. no force needed at all to remove it.
Click to expand...
Very normal. The injector well and injector body should be cleaned to remove any of the "Black Death" residue.

Kaktusjaque said:
After putting everything back together, I am getting exhaust and fuel blow back from around the injector. A new copper o ring was used when replacing too. Just wondering why my injector is not getting a good seal.
Click to expand...
As was said in the post above, the injector seat needs to be in good condition with the proper torque + final proper finishing turn(s) applied.

vic
 
D

Dougflas

DAD OWNER
And I have heard the copper seal must be re installed in the proper position. They are not flat but have a concave or convex surface
 
Kaktusjaque

Kaktusjaque

2002 Freightliner
Aqua Puttana said:
The injector well and injector body should be cleaned to remove any of the "Black Death" residue.
vic
Click to expand...
I feel that I have read this somewhere here. But Ill ask, how does one like myself that does not have access to a mechanics shop go about effectively cleaning this out? Is there something I can buy at Home Depot, or Lowes to do this? The hole looks slightly smaller than a 12g shot shell, maybe my gun cleaner kit can get this cleaned up good.
 
2

220629

Well-known member
Kaktusjaque said:
... The hole looks slightly smaller than a 12g shot shell, maybe my gun cleaner kit can get this cleaned up good.
Click to expand...
The well doesn't need to be spotless, just basically cleaned off. If a shotgun brush fits even loosely into the well it will work.

Check the injector change threads for suggestions about what solvents work to loosen the carbon deposit "Black Death" residue. There are various opinions. Choose a product that seems best for you (having one on hand would affect my selection).

vic
 
2

220629

Well-known member
Dougflas said:
And I have heard the copper seal must be re installed in the proper position. They are not flat but have a concave or convex surface
Click to expand...
I've heard that, and I've also heard that it isn't critical.

The malleable shaped washer is being compressed between two (hopefully) smooth parallel surfaces. The shape is so the malleable copper deforms properly.

My preference would be to have the proud edges of the seal bear against the aluminum thinking that the copper will deform from outside in as compressed against the softer metal (as opposed to the steel injector body). That said, I have no data and don't know if it is at all critical.

vic

Question.
Are thicker the Honda substitute washers also similarly shaped?
 
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