Brass vs Bronze

[Charlie]

Hi All:
I am rebuilding the injectors in my diesel Mercedes. I can't find a brass bottle brush to clean the insides with. I do have a bronze brush for cleaning my guns that would fit pretty well. The nozzle fits into a cylinder that is then inserted in the injector case -- here is a picture 6 Cylinder 603 Monark Diesel Fuel Injector Nozzles w/ Heat Shields - VERY LIMITED SUPPLY | MercedesSource.com The fittings are built to a pretty tight tolerance because no O rings are used. Now my question. Will a bronze brush used to take out the carbon affect the steel of the injector case enough to not allow it to hold pressure?

[Matt sachs]

I have been out of the biz for 20+ years now, but I say no to any kind of brush inside the injector housing. They fit together so closley that if you hold the piston in your hand and warm it up, it wont go back in bore. Its that close of a fix. Way back in the day we cleaned them chemically. I am so far out of date I may be completly off base here.

[Charlie]

Matt what would you use to clean them then. I have tried Carb cleaner but maybe I am not patient enough. The person from Mercedes source says to use a brass brush. I could soak it in carb cleaner some more. Maybe I'll try that.

[delmarrey]

Originally Posted by Matt sachs

I have been out of the biz for 20+ years now, but I say no to any kind of brush inside the injector housing. They fit together so closley that if you hold the piston in your hand and warm it up, it wont go back in bore. Its that close of a fix. Way back in the day we cleaned them chemically. I am so far out of date I may be completly off base here.

They are .0002-3" clearance between the sliding parts. One scratch and they're done. I'd take them to an injector shop that can inspect and/or rebuild them. Injectors should be chemically cleaned.

FYI- -A micron, short for micrometer, is a unit of measurement equal to one millionth of a meter. A micron is actually 0.000039 of an inch. Diesel fuel should be filtered at 5 microns or smaller.

Here is an article that talks about injectors.>>> http://www.sacea.org.za/.%5Cdocs%5CS...s_2_Shrunk.pdf

[Matt sachs]

We used an ultra sonic cleaner, but I don't remember the name of the chemical we used. Its easier to screw them up than to fix them.

[Charlie]

Thanks Matt and Del. There is an internet forum on the Mercedes injectors and it goes into detail on how to clean them. I have two sets of injectors and recently bought an injector tester. I test the injectors by holding them 100lbs below pop pressure to see if they leak. I was able to get four of them to hold and two didn't. I'll try to soak the injector in carb cleaner and loosen up the carbon then hit it with a nylon bottle brush. If that doesn't work I will hit it with a bronze brush and bench test the injector. If it holds on a bench test I will install it in the car. Some of the injectors are easier to remove then the others so I will put the one I clean with a brush in an easy to remove spot and bench test it after a thousand miles or so. Because I have six other injectors to choose from to rebuild I trust this will work out. BTW these Mercedes engines are renowned for their ability to keep running some of them have 1million miles on an original block in taxi cabs in Germany so this is not representative of other engines.

[unbusted67]

Originally Posted by Charlie

Thanks Matt and Del. There is an internet forum on the Mercedes injectors and it goes into detail on how to clean them. I have two sets of injectors and recently bought an injector tester. I test the injectors by holding them 100lbs below pop pressure to see if they leak. I was able to get four of them to hold and two didn't. I'll try to soak the injector in carb cleaner and loosen up the carbon then hit it with a nylon bottle brush. If that doesn't work I will hit it with a bronze brush and bench test the injector. If it holds on a bench test I will install it in the car. Some of the injectors are easier to remove then the others so I will put the one I clean with a brush in an easy to remove spot and bench test it after a thousand miles or so. Because I have six other injectors to choose from to rebuild I trust this will work out. BTW these Mercedes engines are renowned for their ability to keep running some of them have 1million miles on an original block in taxi cabs in Germany so this is not representative of other engines.

Hey what model Mercedes do you own?

[sdowney717]

I would consider 90% rubbing alcohol to clean these.
You can use both a carb cleaner and then later the alcohol.
And a small nylon bristle brush. I have found alcohol dissolves a lot of deposits.

[Charlie]

Originally Posted by unbusted67

Hey what model Mercedes do you own?

We have a rare creature. A 1987 300td wagon. One of the few six cylinder diesels. 260k miles and still going. Hopefully the injector rebuilds will allow me to say still going strong.

[Charlie]

Originally Posted by sdowney717

I would consider 90% rubbing alcohol to clean these.
You can use both a carb cleaner and then later the alcohol.
And a small nylon bristle brush. I have found alcohol dissolves a lot of deposits.

I'll try that if the carb cleaner doesn't work. It is actually a stronger solution that is made for parts to soak in.

[GordMay]

Did you see: Diesel Purge Mercedes diesel maintenance tips

[David M]

Carb cleaner, brake cleaner or electronics cleaner.

[delmarrey]

Originally Posted by GordMay

Did you see: Diesel Purge Mercedes diesel maintenance tips

Another good one Gord! This could be applied to boats as well.

[travler37]

From the good old days of pissing off grandma,
disaemble injector.Insert said parts one injector per glass mason jar.Remove air pump from her fish tank.Add 1/2 kerosene and 1/2 Hows{fuel additive in states} to said jars.Put airline from grandmas pump into jar 1.....let it pump air and circulate kero/hows....
Now is the important part....duck grandma untill all six have ben circulated/soaked for at least a day each.When she finds out duck her high heals flying at your head........
that said has CLEANED any injector problrm i have said.Circulate for 24 hours per jar................If it is worn then your just going to get out the boat book...grins
My Life
Mark

[Charlie]

At over 200lbs Grandma never wore high heels but she did come after us grandkids with sensible shoes.LOL