injector o-ring replacement?...again

[56 nomad]

hello,
sorry to ask the obvious as many of you have done this several times and it must seem like a no brainer and very simple to you...my apologies....i still need your advice.
i have read the posts as well as pelican procedure but still have questions...found 2 injectors with vacuum leaks (carb cleaner method). looks easy as many state , but a few posters have said that the injector sleeves have cracked on them and they had problems getting all the pieces out.
can i just remove the injectors with-out messing with the sleeves, is there a special tool or can they be gently levered out after a good soaking with wd40?
i do not want to start down a slippery slope as i am trying to cure this popping issue when cold...and this is the next step in what i hope will be a short but pleasant journey (LOL).
1983 sc
regards, ben

[psalt]

Ben,

The injector sleeves are staked in by distorting the edge with a punch. Many times when you pull the injector, the sleeve will come out and break up over the stakes. The sleeves are sealed with the same Oring material as the injector seals, but it is exposed to the heat of the runner, baked at a higher rate and more likely to leak. My advice is to grind off the stakes, clean off the swarf, pull the injectors and sleeves and replace both seals. If you grind off the stakes there is a good chance you will not damage the sleeves and you can just replace the Orings.

Paul

[Walt Fricke]

Ben

When I pull injectors I try to have a couple of spare sleeves (and their seals) on hand, in case a sleeve comes out with the injector and gets damaged. If you plan to deal only with the ones which you have identified as leaking, I'd have that many sleeves on hand.

But Paul is suggesting that the leak may be through the sleeve seal, not the injector seal, in which case new injector seals aren't likely to do much good.

Your call.

When you do replace sleeves you must restake, so they are held in place. You can fabricate something you can hit with a hammer to make new stakes.

Walt

[56 nomad]

Originally Posted by Walt Fricke

Ben

When I pull injectors I try to have a couple of spare sleeves (and their seals) on hand, in case a sleeve comes out with the injector and gets damaged. If you plan to deal only with the ones which you have identified as leaking, I'd have that many sleeves on hand.

But Paul is suggesting that the leak may be through the sleeve seal, not the injector seal, in which case new injector seals aren't likely to do much good.

Your call.

When you do replace sleeves you must restake, so they are held in place. You can fabricate something you can hit with a hammer to make new stakes.

Walt

walt,
will eventually replace them all but for the initial run just the 2 that seem to have vacuum leaks. want to see if that will help with the bad gas milage and popping i have just started experiencing.
i will look at them after dinner , not sure what re-staking means, is it like mushrooming the top or slightly pushing them out so they bite and bind a little. how do you keep the garbage out of the orifice is the sleeve material a hard plastic? also is there special tool that i should get?
just feel its sometimes better to do it yourself and wanted the advice of those that have been there before and done it in order to learn from their successes....mechanical f.i is not easy but cis makes my 58 fuel car seem simple to work on.
thanks , ben

[56 nomad]

Originally Posted by psalt

Ben,

The injector sleeves are staked in by distorting the edge with a punch. Many times when you pull the injector, the sleeve will come out and break up over the stakes. The sleeves are sealed with the same Oring material as the injector seals, but it is exposed to the heat of the runner, baked at a higher rate and more likely to leak. My advice is to grind off the stakes, clean off the swarf, pull the injectors and sleeves and replace both seals. If you grind off the stakes there is a good chance you will not damage the sleeves and you can just replace the Orings.

Paul

paul.
would you use a dermal tool for this and after the material is removed how do you grab the sleeve to pull it out..special unobtainium tool?
thanks , ben

[psalt]

Ben,

Yes, a Dremel works well, and blow away the dust. The idea here is too grind away the stakes before you attempt to pull the injector. If the sleeve comes out, then you have to remove the stakes with an open manifold. The stakes are made with a square punch, peening over a bit of aluminum to hold in the smooth sleeve. This was a mistake in my opinion, some other make CIS cars use threaded injector sleeves that are not so prone to leaking. Like Walt says, it is a good idea to have replacements handy, before you do anything.

[56 nomad]

Originally Posted by psalt

Ben,

Yes, a Dremel works well, and blow away the dust. The idea here is too grind away the stakes before you attempt to pull the injector. If the sleeve comes out, then you have to remove the stakes with an open manifold. The stakes are made with a square punch, peening over a bit of aluminum to hold in the smooth sleeve. This was a mistake in my opinion, some other make CIS cars use threaded injector sleeves that are not so prone to leaking. Like Walt says, it is a good idea to have replacements handy, before you do anything.

psalt,
thanks, nice to know they are aluminum as i thought they were a hard rubber or plastic as in some of the posts those members seemed to indicate they were shattering
flaking and falling into the chambers. any special tools for removal or install...
in terms of sequence , would you install the injector into the sleeve or assemble everything and then stake the sleeve.... what is the best lubricant to use for reassembly?
thanks for your help, ben

[Walt Fricke]

Ben

The manifold is aluminum, the sleeve is some kind of rather brittle plastic (the older it is, the more brittle it is, it seems to me), and the injectors, as you know, are metal.

When I have had to stake a new one in place I have done it before putting the injector into it. Seemed the logical way to go.

And, since you often can (and hope you can) remove the injector without removing the sleeve, it never occurred to me to put the injector into the sleeve before inserting the sleeve (and then staking). The sleeve might be stronger - better able to handle the sideways pushing of that fat rubber donut that holds the injector in - if it is already in the manifold when installing the injector.

I think any lubricant which is not harmful to rubber would do to help ease things in. I happen to have a small tube of rubber grease (for brake seals), but a little of just about any ordinary grease or oil ought to be compatible with the seals. If you even use a lubricant at all.

[VFR750]

A quick solution is to apply black rtv to the top of the sleeve/injector and seal it up. I saw this on a club racer, and tried it myself. Worked great! Cold popping stopped.

[56 nomad]

Originally Posted by Walt Fricke

Ben

The manifold is aluminum, the sleeve is some kind of rather brittle plastic (the older it is, the more brittle it is, it seems to me), and the injectors, as you know, are metal.

When I have had to stake a new one in place I have done it before putting the injector into it. Seemed the logical way to go.

And, since you often can (and hope you can) remove the injector without removing the sleeve, it never occurred to me to put the injector into the sleeve before inserting the sleeve (and then staking). The sleeve might be stronger - better able to handle the sideways pushing of that fat rubber donut that holds the injector in - if it is already in the manifold when installing the injector.

I think any lubricant which is not harmful to rubber would do to help ease things in. I happen to have a small tube of rubber grease (for brake seals), but a little of just about any ordinary grease or oil ought to be compatible with the seals. If you even use a lubricant at all.

walt,
if i understand you it might be alright to do the injector only if that stops the leak and if not then do the sleeve...right? if the sleeve needs to come out how have you "gripped" it to pull it out?
thanks , ben

[euro911sc]

Hey Ben,

If all this is in-car then you can use a dremel to grind/sand down the stakes. Plug the sleeve with some paper towel soaked with wd-40. Use a shop vac right next to it and you should be able to keep the aluminum dust from getting too much into the intake. But, much of the time you cant easily see the marks in the aluminum:



After cleaning and re-staking you can see the square Porsche marks and my center punch marks with the corresponding deformed metal:


When you re-stake the sleeve use an automatic center punch ($2.99) works like a champ and its nice and small:

Automatic Center Punch

Its also very handy in the car when you get rolled over and end up in the canal... happens a lot around here. It will shatter a side window instantly so you can get out.

The bottom side is usually quite gunky so the sleeves get stuck


To remove the sleeve with out destroying it is not easy. I'd use 1-2 coat hangers with bent tips so you could pull evenly 180 deg. apart. I might even coat them with a thick grease so any fracturing of the sleeve gets stuck to the hangers and comes out with the sleeve. Sometimes the sleeve is really stuck in there. I had a few I had to hammer out when I rebuilt my engine because they were that stuck. Just make sure you don't scar the wall of the hole with a sharp coat hanger tip. If you did not plan on re-using the sleeve I might glue a dowel rod into the sleeve so I could pull it out the next day.

All clean and ready to go:


I would do the injectors 1st as the sleeve has the sleeve and then the o-ring to prevent leaks. If you still leak after that get to the sleeves.

-Michael

[56 nomad]

Originally Posted by euro911sc

Hey Ben,

If all this is in-car then you can use a dremel to grind/sand down the stakes. Plug the sleeve with some paper towel soaked with wd-40. Use a shop vac right next to it and you should be able to keep the aluminum dust from getting too much into the intake. But, much of the time you cant easily see the marks in the aluminum:



After cleaning and re-staking you can see the square Porsche marks and my center punch marks with the corresponding deformed metal:


When you re-stake the sleeve use an automatic center punch ($2.99) works like a champ and its nice and small:

Automatic Center Punch

Its also very handy in the car when you get rolled over and end up in the canal... happens a lot around here. It will shatter a side window instantly so you can get out.

The bottom side is usually quite gunky so the sleeves get stuck


To remove the sleeve with out destroying it is not easy. I'd use 1-2 coat hangers with bent tips so you could pull evenly 180 deg. apart. I might even coat them with a thick grease so any fracturing of the sleeve gets stuck to the hangers and comes out with the sleeve. Sometimes the sleeve is really stuck in there. I had a few I had to hammer out when I rebuilt my engine because they were that stuck. Just make sure you don't scar the wall of the hole with a sharp coat hanger tip. If you did not plan on re-using the sleeve I might glue a dowel rod into the sleeve so I could pull it out the next day.

All clean and ready to go:


I would do the injectors 1st as the sleeve has the sleeve and then the o-ring to prevent leaks. If you still leak after that get to the sleeves.

-Michael

michael,
wow!! as they say a picture is worth a thousand words......... thanks to all the members that responded....comments and photos have answered my questions and i will give it a shot this weekend.
regards to all , ben

[jmitro]

great information; a very timely thread for me. thanks guys.

Originally Posted by VFR750

A quick solution is to apply black rtv to the top of the sleeve/injector and seal it up. I saw this on a club racer, and tried it myself. Worked great! Cold popping stopped.

works great........until you're the one that has to remove all that nasty rtv like i am now. i wouldn't recommend this el cheapo repair. fix it right the first time.

[Walt Fricke]

The "staking" has two functions: 1) to keep the sleeve, and thus the injectors, in place while you are running the engine. It doesn't take much to do this, especially where you have steel injection lines. There aren't any forces trying to eject injectors, at least in a normally aspirated motor.

2) to keep the sleeve in place when you pull the injectors. Injectors are a wear item, and from time to time (long time intervals, to be sure) can stand being checked and cleaned or replaced. The sleeves ought to last through several injector removal cycles without getting pulled out when you try to get an injector out.

Is an automatic center punch, with its rather small sharp end, adequate to accomplish 2)? Or does the Lliputian approach (lots and lots of small punch distortions) do the job?

Walt

[Walt Fricke]

Or are my center punches just too small - I see you just used three of them, and though smaller than the factory's rectangular stake tool, are not just the pin pricks I am used to from my el cheapo punch.

[euro911sc]

Dunno really. I have yet to attempt to pull an injector out! I have been considering it for a while, but the engine runs nicely so I'm not going to mess with it

[VFR750]

No need for "el cheapo"

Track car in question that use rtv is regularly FIC in club racing. 911sc running 1:00 laps at lime rock.

Removing the rtv took a little bit of time, yes. No big deal for me; I had already removed the intake. Obviously, i have new parts, just in case i reinstall.

For a good solid fix, the rtv works. If you are rebuilding, concours, or just want it stock looking, replace the injector sleeve and o-rings. BTW, Bentley manual recommends lubricating the orings with fuel. Not sure why, except, that is what they are exposed to in service.

great information; a very timely thread for me. thanks guys.

Quote de VFR750

A quick solution is to apply black rtv to the top of the sleeve/injector and seal it up. I saw this on a club racer, and tried it myself. Worked great! Cold popping stopped.

works great........until you're the one that has to remove all that nasty rtv like i am now. i wouldn't recommend this el cheapo repair. fix it right the first time.