Injector seals again boooooooooo

[sms78]

Hey guys/gals i just wondered what anybody thought of a idea i had today because i think im still getting leaks from one of the injectors . Due to suspected crud down one of the injector bolt holes or maybe all i dont know I dont think im getting the injectors bolts down enough to seal them . So what im asking is what if i cut a few mm off the bottom of each injector bolt so it clears the crud . Is that wise or am i sounding like a CRAZY FOOL! ???? The injector seats are clean and the correct washers are being used . Its just the ticking noise is little bit annoying after all the effort but then i can turn the radio up i suppose.

 

[Number_Cruncher]

The best solution would be to clear the crud out

The next best solution would be to put a hard washer under the bolt head.

As, if I understand correctly, these highly loaded bolts screw directly into the aluminium for the head, you don't want to do anything to compromise their thread engagement.

 

[Cole@MBS]

Have the seats re-cut is the best way to get a correct seal!!

 

[sms78]

The seats have been recut look perfect . As for the crud, i got out all i could see . Dont know if there is any right at the bottom . I know one of the bolt holes has a hole in the bottom because when i pulled out the bolt other day all water came out . Would the washer under the bolt work you reckon ?

 

[Number_Cruncher]

>> I know one of the bolt holes has a hole in the bottom because when i pulled out the bolt other day all water came out .

That probably means that someone has drilled to deep while making a previous thread repair. Eek!

Would the washer under the bolt work you reckon ?

Yes, but, you must make sure the washer is made from harder material than the bolt, and than the clamp. You do not want the bolt's preload being lost due to the washer crushing.

Why do you think the bolt is bottoming out in the hole? It sounds unlikely to me.

 

[sms78]

I dont know its just a crazy thought thats all that the new bolts are stretching or getting slightly longer when they get hot then the old ones did making the injectors slightly loose and leak . Are all the injector bolts the same Length for all c.d.i engines?

 

[panason1c]

sms78, it is important that you replace the stretch bolt AND the CLAMP-FORK when renewing an injector copper seal, i would use a drill bit with grease on the tip BY HAND to clean up the bottom of the hole .

 

[sms78]

CURSES ive never replaced any of the clamp forks before . Its a good point because they could be slightly out of shape never thought about that .thanks

 

[Number_Cruncher]

>>AND the CLAMP-FORK

Really? That sounds odd to me. Why would you need to replace the fork? Sorry, I don't get it!

 

[Cole@MBS]

Its stated in WIS, must replace bolt and clamp everytime the injector is removed/fitted!!

 

[Number_Cruncher]

>>Its stated in WIS

Yes, I don't for a second doubt it's a true assertion, but, I'm struggling to understand exactly why that's the case. What's the engineering logic behind the WIS instruction?

The bolt, yes, that will have deformed in a once only way as you tighten it up.

Are there any weak, sacrificial parts of the clamp yoke which will "give" once to create a really good contact and then not yield again a second time?

It would be much more standard design to make the clamp yokes very stiff in comparison with the bolt, and such that you wouldn't have to replace them.

Has anyone got a good piccie of a new clamp yoke?

 

[Cole@MBS]

The reason behind it are due to when the dealers first started to replace injectors, there were a few which left the workshop and the clamp snapped one of its prongs and shot the injector into the bonnet! so as course now they say replace the clamp!

 

[Cole@MBS]

>>Its stated in WIS

Yes, I don't for a second doubt it's a true assertion, but, I'm struggling to understand exactly why that's the case. What's the engineering logic behind the WIS instruction?

The bolt, yes, that will have deformed in a once only way as you tighten it up.

Are there any weak, sacrificial parts of the clamp yoke which will "give" once to create a really good contact and then not yield again a second time?

It would be much more standard design to make the clamp yokes very stiff in comparison with the bolt, and such that you wouldn't have to replace them.

Has anyone got a good piccie of a new clamp yoke?

Not very clear but this is what happens

 

[panason1c]

>>AND the CLAMP-FORK

Really? That sounds odd to me. Why would you need to replace the fork? Sorry, I don't get it!

Now do you 'get it' ??

 

[television]

Now do you 'get it' ??

Hi jacked the post,, lovely to see you posting again

 

[Number_Cruncher]

>>Now do you 'get it' ??

Yes.... and no!

Yes in the sense that I don't doubt or dispute anything that's been said about the need to replace these yokes, and the possible consequences.

No in the sense that there is something that is deeply and intrinsically wrong with this joint. The yoke, if the joing is working properly, should be subject to fatigue forces low enough to obtain so-called "infinite life", and yoke failure simply should not happen.

The important words there are "if the joint is working properly" - the ongoing leak problems suggest that the joint isn't working properly, and the loadpath via the injector to head seal is not working effecively, hence the leakage, and hence the overloading of the yoke.

As a long slender bolt is used, and a torque plus angle is specified suggests to me that MB had problems with this joint at the development stage - I would expect that they began their development program with a different design altogether.

Please don't feel that I'm being needlessly argumentative or difficult - I'm just trying, principally to satisfy my technical curiosity, to find out a bit more about how and why these joints fail, rather than simply accepting the status quo.

 

[sms78]

s-a-m- unit on your picture is that an injector that has flown out? looks like theres an injector missing in between the two ? Might experiment with the washers because they flat one side and curved the other. might try em with the curved bit facing the injector next time . That is if all the injector forks dont all snap and fire 6 holes into my bonnet lol Im gonner be well paranoid now

 

[kebo57]

The seats have been recut look perfect . As for the crud, i got out all i could see . Dont know if there is any right at the bottom . I know one of the bolt holes has a hole in the bottom because when i pulled out the bolt other day all water came out . Would the washer under the bolt work you reckon ?

Hi you need to up date your profile, what sort of car you have, where you are located "The seats have been recut look perfect" looks not quite as good as actualy perfect, what about the bottom of the injector that would need to be perfect as well as the carbon will pass the bore of the copper washer & under the injector to copper washer faces = leaking again with perfect recut seatings
When I did my injectors I back turned the bottom face (0.002") of the injector to get it flat
I can re-cut your injector seats if you live local to me, north west & I know what car you have

Kevin

 

[kebo57]

s-a-m- unit on your picture is that an injector that has flown out? looks like theres an injector missing in between the two ? Might experiment with the washers because they flat one side and curved the other. might try em with the curved bit facing the injector next time . That is if all the injector forks dont all snap and fire 6 holes into my bonnet lol Im gonner be well paranoid now

Hi them washers shouldn't be "flat one side and curved the other" they should be same both sides, you need the correct ones I turned / machined one up from copper annealed it, fitted it, and it leaked, so I bought the correct ones they where twice as soft as the one that I made & it didn't leak

Kevin

 

[sms78]

i live in northamptonshire area and the car is a w210 e320 c.d.i. . I have a injector seat cutting kit that i have used on a few cars and it works great . Works better on the old 300 diesel engine . Do the 320 c.d.i. heads have some sort of hardened insert in the injector hole attached to the head ? I was only just thinking of this today . will have a good look when i pull the injectors out for a 3rd time and replace the studs,washers and now the yokes lol