Jump to content
Rob Y

Injector O ring change

Recommended Posts

Hi everyone - just a quick piece of advice please from anyone who has done this, it may seem like a simple question and I am probably looking for reassurance as much as anything but here goes. I am planning on changing the internal (and external) O-rings on the injectors on my 6 and have read the previous threads on this so I am pretty confident about what I am doing. The injectors weep a bit of fuel when I take them out and there is movement there that suggests this is the right thing to be doing - the way the car starts also adds to this conviction.

The instructions are "remove the cir-clip or C ring at the end of the injector and then push the inner part out through the body towards the injector inlet. I can see this very small C clip that is mentioned - what is the best method to remove this C ring please? I can see a risk of it springing off and getting lost. What about replacing it after changing the o-rings - is there also a tried and tested method for this please.

 

Thanks to all contributors on this so far that has given me the confidence to try this - I have bought the Viton O rings according to the information gleaned from these pages already.

 

I look forward to hearing your comments.

 

Cheers

 

Rob

Share this post


Link to post
Share on other sites

Rob,

 

I removed my C clips with a small sharp screwdriver. Placed injector and screwdriver inside a sealable, clear plastic bag. Sealed bag and held screwdriver from outside bag and popped off.

 

Obviously easier without a bag but then I didn't have any spare clips.

 

 

Alan

Share this post


Link to post
Share on other sites

Hi everyone - just a quick piece of advice please from anyone who has done this, it may seem like a simple question and I am probably looking for reassurance as much as anything but here goes. I am planning on changing the internal (and external) O-rings on the injectors on my 6 and have read the previous threads on this so I am pretty confident about what I am doing. The injectors weep a bit of fuel when I take them out and there is movement there that suggests this is the right thing to be doing - the way the car starts also adds to this conviction.

The instructions are "remove the cir-clip or C ring at the end of the injector and then push the inner part out through the body towards the injector inlet. I can see this very small C clip that is mentioned - what is the best method to remove this C ring please? I can see a risk of it springing off and getting lost. What about replacing it after changing the o-rings - is there also a tried and tested method for this please.

 

Thanks to all contributors on this so far that has given me the confidence to try this - I have bought the Viton O rings according to the information gleaned from these pages already.

 

I look forward to hearing your comments.

 

Cheers

 

Rob

Hi Rob

 

The viton 'O' rings must be made out of viton B grade and not viton A as current fuel will still attack A type!

 

Bruce.

Share this post


Link to post
Share on other sites

Rob,

 

I removed my C clips with a small sharp screwdriver. Placed injector and screwdriver inside a sealable, clear plastic bag. Sealed bag and held screwdriver from outside bag and popped off.

 

Obviously easier without a bag but then I didn't have any spare clips.

 

 

Alan

Hi Alan,

That sounds great - pretty much what I was thinking. I have been nervous about doing this as it is new for me but from the general comments I have read and looking at it I am reasonably cofident in doing this. Once mastered it will be useful for the future too.

Cheers

 

Rob

Share this post


Link to post
Share on other sites

Hi Rob

 

The viton 'O' rings must be made out of viton B grade and not viton A as current fuel will still attack A type!

 

Bruce.

Hi Bruce,

I have ordered Viton A. From what I can see this should be ok - only marginal difference between A and B for this application I would think. I even read that Nitrile is ok - tested on motorbikes but same fuel.. If I can do the job as easily as I hope then I can change the O-rings each year which should avoid any major issues I would think. I had to order a minimum quantity of o-rings so I will have plenty of stock, I might soak one in petrol and see what happens over time.

 

Rob

Share this post


Link to post
Share on other sites

I have to say that in 20 years I have never had a problem with injectors apart from once having a bit of chaff stuck in one once that prevented it from closing properly.

Oops should I have said that I haven't had problems? 😱

Share this post


Link to post
Share on other sites

Before changing the seals make sure the valve seats are not the problem

Clever comment..... and certainly one of the key parameter not to forget for a consistent result (Valve effect and the diffusion)

Share this post


Link to post
Share on other sites

Clever comment..... and certainly one of the key parameter not to forget for a consistent result (Valve effect and the diffusion)

True but its so easy to change the o-rings and see if this fixes the problem - so why not do that first? Current o-rings are old and there is movement there so worth changing even if there are other issues. Problems are not so bad either so I am pretty confident the o-ring change will make things better. If after this there are still problems then the valve seats are the next place to look.

Share this post


Link to post
Share on other sites

True but its so easy to change the o-rings and see if this fixes the problem - so why not do that first? Current o-rings are old and there is movement there so worth changing even if there are other issues. Problems are not so bad either so I am pretty confident the o-ring change will make things better. If after this there are still problems then the valve seats are the next place to look.

Hello Rob Y,

 

Correct and pragmatic approach, I follow your step by step process.

 

My point was just to mention (as K_raven_smith), the change of the O ring is not a magic button and other aspects (Valve seat, spring..) are other key parameters and at a certain level the injector must be restored end to end by an experienced expert with parts following all specifications.

 

Best regards

Share this post


Link to post
Share on other sites

Well I changed the o rings today. As mentioned very easy job. Nice tip about taking the c ring off in a bag but they didn't fly off in fact. Old o rings were hard, cracked and square and everything was lose. With the new o rings fitted it's all much tighter. Starts beautifully now and runs smoothly on all cylinders at all speeds, very pleased with the result. Definitely a job not to be scared of. Thanks to this forum for info on the o ring sizes.

Share this post


Link to post
Share on other sites

Well I changed the o rings today. As mentioned very easy job. Nice tip about taking the c ring off in a bag but they didn't fly off in fact. Old o rings were hard, cracked and square and everything was lose. With the new o rings fitted it's all much tighter. Starts beautifully now and runs smoothly on all cylinders at all speeds, very pleased with the result. Definitely a job not to be scared of. Thanks to this forum for info on the o ring sizes.

How did you adjust/test the opening pressure on the injector?

Share this post


Link to post
Share on other sites

How did you adjust/test the opening pressure on the injector?

I didn't adjust anything, just changed the o rings, left the opening pressure as it was. Comments on the forum have suggested it's rare that this needs adjusting.

Share this post


Link to post
Share on other sites

I didn't adjust anything, just changed the o rings, left the opening pressure as it was. Comments on the forum have suggested it's rare that this needs adjusting.

Thanks.

Share this post


Link to post
Share on other sites

Where did you get the viton b seals?

I didn't use Viton B I used Viton A. According to the o ring suppliers this is fine for unleaded petrol. Even if it degrades it would take some time and as they are so easy to change it's not a problem. I suspect the ones I took out were the originals so I don't think it will be a problem. There are loads of o ring suppliers on line, I used one called Polymax. They have a minimum order value of £10 so I bought 30 of the inner ones and 40 of the outer, so should last me a while.

Share this post


Link to post
Share on other sites

Just a note on the phrase "Suitable for unleaded petrol" :

This is used by suppliers, but it does NOT mean this is also suitable for E10 or E15 fuel, containing 10 resp. 15% ethanol.

I bought some fuel hose from James Paddock, which was "suitable for unleaded fuel".

This is entirely correct, the hose was according SAEJ30R6, so as long as fuel without ethanol is used, an acceptable hose.

Did not know then what I know now:

Hoses per SAEJ30 R6 allows a 40 times higher loss due to permeation than the hoses suitable for E10, per SAEJ30 R14).

Waldi

Share this post


Link to post
Share on other sites

Just a note on the phrase "Suitable for unleaded petrol" :

This is used by suppliers, but it does NOT mean this is also suitable for E10 or E15 fuel, containing 10 resp. 15% ethanol.

I bought some fuel hose from James Paddock, which was "suitable for unleaded fuel".

This is entirely correct, the hose was according SAEJ30R6, so as long as fuel without ethanol is used, an acceptable hose.

Did not know then what I know now:

Hoses per SAEJ30 R6 allows a 40 times higher loss due to permeation than the hoses suitable for E10, per SAEJ30 R14).

Waldi

So Waldi even R9 is not up to the job?

Share this post


Link to post
Share on other sites

Waldi as you too are on a crusade here too😜

What tank are you using?

Did you see also see that aluminum may not resist?

Edited by Rem18

Share this post


Link to post
Share on other sites

Just a note on the phrase "Suitable for unleaded petrol" :

This is used by suppliers, but it does NOT mean this is also suitable for E10 or E15 fuel, containing 10 resp. 15% ethanol.

I bought some fuel hose from James Paddock, which was "suitable for unleaded fuel".

This is entirely correct, the hose was according SAEJ30R6, so as long as fuel without ethanol is used, an acceptable hose.

Did not know then what I know now:

Hoses per SAEJ30 R6 allows a 40 times higher loss due to permeation than the hoses suitable for E10, per SAEJ30 R14).

Waldi

There is a big difference to the application though. Fuel hose in constant contact with the fuel and the resultant effect being fuel permeability, compared to these o rings which are not in constant contact with the fuel and then the only effect is that they might swell slightly, so would not cause any issues. I have seen reports on tests done on o rings in modern unleaded fuels and even nitrile worked fine, so I am not worried about the marginal difference between the 2 Viton grades for this application. I am pretty sure the ones I took out were original and probably nitrile, so after 40 years you start to see an effect and even then it's not actually critical.

Share this post


Link to post
Share on other sites

There is a big difference to the application though. Fuel hose in constant contact with the fuel and the resultant effect being fuel permeability, compared to these o rings which are not in constant contact with the fuel and then the only effect is that they might swell slightly, so would not cause any issues. I have seen reports on tests done on o rings in modern unleaded fuels and even nitrile worked fine, so I am not worried about the marginal difference between the 2 Viton grades for this application. I am pretty sure the ones I took out were original and probably nitrile, so after 40 years you start to see an effect and even then it's not actually critical.

Yes originals have held up quite well.

The problem here is if one is going to upgrade stuff, it would be good to upgrade the lot from tank to pipes to metering system seals.

It's a bit if a nightmare really.😱

Edited by Rem18

Share this post


Link to post
Share on other sites

Rob,

I'm with you, for an internal O-ring permeation is not an issue at all.

Compatibility with E10 may be, but even Viton A is better than the original O-ring and probably last for a longer time.

 

Rem,

No, not on a crusade:)

I did read an article about aluminum tanks and ethanol containing fuel, but my tank is steel, so did not look/dig to deep.

 

R9 spec hose is tested with a non-ethanol test-fuel and has a low allowable permeation of 15 g/m2/day which is very good but.... the spec indicates the permeation may be "significantly higher when exposed to ethanol containing fuel like E10", see par. 4.5 of the spec.

R14 is the only type of hose tested with fuel containing 10% ethanol, and still has a low permeation of 15 g/m2/day.

 

The above about permeation is based on the 2008 edition of SAEJ30, I do not have a copy of the latest (2012) edition.

 

Regards,

Waldi

Share this post


Link to post
Share on other sites

Rob,

I'm with you, for an internal O-ring permeation is not an issue at all.

Compatibility with E10 may be, but even Viton A is better than the original O-ring and probably last for a longer time.

 

Rem,

No, not on a crusade:)

I did read an article about aluminum tanks and ethanol containing fuel, but my tank is steel, so did not look/dig to deep.

 

R9 spec hose is tested with a non-ethanol test-fuel and has a low allowable permeation of 15 g/m2/day which is very good but.... the spec indicates the permeation may be "significantly higher when exposed to ethanol containing fuel like E10", see par. 4.5 of the spec.

R14 is the only type of hose tested with fuel containing 10% ethanol, and still has a low permeation of 15 g/m2/day.

 

The above about permeation is based on the 2008 edition of SAEJ30, I do not have a copy of the latest (2012) edition.

 

Regards,

Waldi

Heh Waldi

I am on a crusade with you 😜

There are so many rubber parts from tank to cylinder it's becoming a minefield...

Is your tank just steel?

I sloshed my original with liner 18 years ago but now it's time to upgrade that too.

Is the Gates SAEJ30 R14?

 

Tony

Edited by Rem18

Share this post


Link to post
Share on other sites

Hi Tony,

As long as you are on a crusade WITH me I'm happy:)

It is a bit disappointing that most of our suppliers do not anticipate on E10 or E15 in material selection.

To their defense, many other suppliers (non-TR) don't either.

It is the 8 bars fuel pressure inside the car that makes me want to dig a bit deeper, and the desire to get it right first time, which is not always possible as we know.

 

To answer your questions:

My tank is bare steel currently, no internal coating yet, and it is not severely corroded internally, but I plan to apply an internal coating before installation, but want to increase the outlet diameter first. I had a flake of rust in the tank outlet when I dismantled it, non sure where it came from, so a coating may be a good pre-caution.

I also plan a decent size fuel filter between tank and pump, so this will catch most of the particles that could still be released.

 

The Gates type 4219 BF hose for the our high pressure applications (pump discharge and inlet MU) meets SAEJ30 R14T2, except for kink.

For the low pressure applications (the rest) I plan to use Gates 4219BG Barricade hose, which meets SAEJ30R14T1.

Indexes T1 and T2 are aging-at-temperature related, both would be ok for our applications (T2 having slightly higher allowables).

 

Note: i have no connections with Gates, Cohline and others may have suitable hoses also, I simply did not investigate these.

 

Regards,

Waldi

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...

×
×
  • Create New...

Important Information

Please familiarise yourself with our Terms and Conditions. By using this site, you agree to the following: Terms of Use.