Replace O-rings in vacuum pump. What size? Need spare to measure. Anyone can help? CT

[aviator79]

So I would rather replace the o-rings in the vacuum pump if that would fix the leaking. Seeing the o-ring set for sale on ebay by RKX it seems a simple solution is to replace the o-rings with viton o-ringds from McMaster Carr or other company if we knew the sizes. Has anyone bought one these o-ring kits? Over 200 have sold from this auction alone so would think someone on here had bought one.

https://www.ebay.com/itm/232205692818

I have seen a few people of posted a link to them on here. I know @Dondgb rebuilt his with this kit.
http://www.audizine.com/forum/showth...1#post12844599

Have they worked? Seems to me they would work fine but overpriced at $30.

Does anymore have a spare vacuum pump that can accurately measure the size o-rings needed? I mainly need to measure the back but also the check valve.

The front is (IDK if this is OD or ID so will assume ID)

2mm X 53mm (for original pump)
https://www.europaparts.com/vacuum-p...06d145117.html
"To be used for 06D145100E pump only."
McMaster carr (does not sell 53mm ID):
Chemical-Resistant Super-Resilient Viton® Fluoroelastomer O-Rings
ID52 56 Durometer 75A (Medium) ASTM D2000, SAE J200 -15° to 400° Black 5 1295N266 $6.56
Chemical-Resistant Viton® Fluoroelastomer O-Rings
ID 52 OD 56 Width 2mm Durometer 75A (Medium) ASTM D2000, SAE J200 0° to 400° Black QT1 PART number 9263K667 $3.09

inch parts are cheaper if would fit
2mm = 0.0787402in
53mm = 2.08661
These would probably fit but IDK
Wd.: 1/16 Fractional (0.070" Actual)
033 ID 2 OD 2 1/8 ID 1.989" OD 2.129" Durometer 75A (Medium) ASTM D2000, SAE AS568, SAE J200 0° to 400° Black QT25 9464K331 $9.02
Thats $0.36/each vs $3.09 each but these are not the super resiant

Chemical-Resistant Super-Resilient Viton® Fluoroelastomer O-Rings
Wd.: 3/32 Fractional (0.103" Actual)
136 2 2 3/16 1.987" 2.193" Durometer 75A (Medium) ASTM D2000, SAE AS568, SAE J200 -15° to 400° Black 5 1288N231 $5.16
137 2 1/16 2 1/4 2.050" 2.256" Durometer 75A (Medium) ASTM D2000, SAE AS568, SAE J200 -15° to 400° Black 5 1288N232 $5.27
$1 each...

or
http://www.theoringstore.com/index.p...ducts_id=41307


2.5mm X 56mm (for revised pump)
https://www.europaparts.com/vacuum-p...6d145117a.html
"To be used for 06D145100F and 06D145100G pump" and I assume H, site needs update.
McMaster carr:
Chemical-Resistant Super-Resilient Viton® Fluoroelastomer O-Rings
ID 56 OD61 Durometer 75A (Medium) ASTM D2000, SAE J200 -15° to 400° Black QT2 1295N482 $5.11
closest they have in inch size
2.5mm = 0.0984252in
56mm = 2.20472in
Wd.: 3/32 Fractional (0.103" Actual) (0.103 minus 0.0984252 = 0.0045748)
Chemical-Resistant Viton® Fluoroelastomer O-Rings
139 ID 2 3/16 OD 2 3/8 ID 2.175" OD 2.381" Durometer 75A (Medium) ASTM D2000, SAE AS568, SAE J200 0° to 400° Black QT10 9464K139 $6.35
140 ID 2 1/4 OD 2 7/16 ID 2.237" OD 2.443" Durometer 75A (Medium) ASTM D2000, SAE AS568, SAE J200 0° to 400° Black QT10 9464K151 $6.40

or
http://www.theoringstore.com/index.p...4cb3b3e1c76d56



Anyone nearby in CT/MA that has an old pump I can borrow to measure back slot for o-ring size?
I am assuming rear is 2.5mm so would probably go with 3/32 as think it would fit but need to measure and 2.5-3" ID I am thinking.

[Hugh@EuropaParts]

Usually doesn't leak from the o ring... everyone who has purchased an o-ring from us eventually buys the pump.

[aviator79]

Usually doesn't leak from the o ring... everyone who has purchased an o-ring from us eventually buys the pump.

I know doesn't leak from front o-ring on vacuum pump that seals to cam chain housing, but from the backside of pump cover which because an OEM seal is not sold everyone just buys new pumps thinking that sense the slot is not round an o-ring will not work.


Which is why i need to measure what size o-ring to buy for the back cover as i posted in OP.

I was only listing the front (toward front of car) o-ring as they might as well be replaced at same time.

I will just remove mine and measure myself as need to replace coolant flange. I had just hoped to do everything at once but taking pump back off to fix later is no big deal. Will update post once i get info.

[hemantpd1]

I had tried re-sealing the leaking backplate, but after few months it started leaking again. Ended up buying the updated vacuum pump.

[KJack]

I had tried re-sealing the leaking backplate, but after few months it started leaking again. Ended up buying the updated vacuum pump.

Yeah, I’ve never heard of anyone successfully stopping the leak with new o-rings or sealant. If mine starts to leak I plan to just replace the pump to avoid a long term headache.

[aviator79]

Yeah, I’ve never heard of anyone successfully stopping the leak with new o-rings or sealant. If mine starts to leak I plan to just replace the pump to avoid a long term headache.

Im sure sealant wont work. Seems silly to replace whole pump if a $5 o-ring will fix it. Only post I found on here where someone replaced the rear backing plate o-ring is from Dondgb where he bought the kit I posted and AFAIK it worked. Anyone else tried replacing o-ring?

I bought a new pump but would much rather find a cheap fix for me and other which is why I made this post. I think a good replacement o-ring will fix leak but who knows.

I am about to do rear coolant flange, cam chain and tensioner, intake cam, cam housing gasket, valve cover gasket...etc. We will see how it goes.

[aviator79]

Edit, of course I forgot to buy the camshaft adjuster N205 06F109257C as I see that is leaking at connector but at least seams will be easy to replace after...just another $160

[4rings5stars]

I, too, tried sealing the pump with the sealant normally used for cam girdles. Worked for about a year.

If the leak bothers you that much, I'd just replace the pump. IIRC, the problem is that the cover warps.

[blauslc92]

I had eyeballed this kit (https://www.rkxtech.com/products/rkx...acuum-pump-kit). I was in a time crunch (as usual), and I didn't want to risk having to rework and fiddle with it, so in the end I opted to buy the new revision pump as mine had the original.
I'm not sure if anyone here has tried it.

[aviator79]

I, too, tried sealing the pump with the sealant normally used for cam girdles. Worked for about a year.

If the leak bothers you that much, I'd just replace the pump. IIRC, the problem is that the cover warps.

Ya if the rear cover warps and o-ring probably wont fix it. I will definitely check to see if mine is flat but dont have a good straight edge to do it accurate. If it does in fact warp a new thicker rear cover should have been designed and sold IMO. It may be that an o-ring replacement will only work on the new pump if it fails.

I had eyeballed this kit (https://www.rkxtech.com/products/rkx...acuum-pump-kit). I was in a time crunch (as usual), and I didn't want to risk having to rework and fiddle with it, so in the end I opted to buy the new revision pump as mine had the original.
I'm not sure if anyone here has tried it.

Well the link I posted is same place, RKX, and shows 200+ have sold so people seem to be buying them; they must not be on here. Reading one review it is a mechanic saying he buys them to offer rebuild vs replacement. I think it would work. I think what happens is the o-ring degrades due to fuel contamination in oil which all DI have. Viton o-rings should stand up to fuel better than what audi probably used originally.

[ahotboy15]

what about used pump, would that be okay or replace with oem new?

[aviator79]

what about used pump, would that be okay or replace with oem new?

OEM new if doing it unless a good rev2 I guess...you decide.


Is it my settings or can you not view post count on this forum?

Car already has revised cam so that saves me some time and money. Did eat thru a cam follower last year and had to replace pump but cam was ok. New follower looks OK but will replace now and every 20kish.

May just use new pump but still want to try replacing o-ring...just dont have time to play and does not seem anyone here cares to find out if there is a cheaper solution to replacing pump. It took me too long to get it off and dont have time to do it again.

I will measure O-ring needed and buy one but to test fit and post up size for other to try if they want.

[ahotboy15]

im sure u can view post count, not sure what you mean but im sure its possible

[blauslc92]

Well the link I posted is same place, RKX, and shows 200+ have sold so people seem to be buying them; they must not be on here. Reading one review it is a mechanic saying he buys them to offer rebuild vs replacement. I think it would work. I think what happens is the o-ring degrades due to fuel contamination in oil which all DI have. Viton o-rings should stand up to fuel better than what audi probably used originally.

Oops sorry for some reason your original link/image didn’t load the first time for me and I misread that you already were asking about the seal kit.
I agree,the kit should work so long as the cover is not warped.
The material, I really wonder. I agree Viton has superior chemical resistance but Buna/Nitrile is just fine with fuel and oils.
Viton supposedly gets hard at low temps, maybe the cycling of temperature is what degrades that seal and/or warps the cover...



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[zzzz05725]

Usually doesn't leak from the o ring... everyone who has purchased an o-ring from us eventually buys the pump.

Hugh, is it possible for oil to contaminate our clutches when this leak occurs? I bought an updated pump as soon as I caught this leak, but there was oil covering my transmission and my clutch started slipping at WOT within a matter of days. I only have driven about 500 miles with my stage 2 tune, but I'm not ruling the tune out as the cause by any means.

[4rings5stars]

Hugh, is it possible for oil to contaminate our clutches when this leak occurs? I bought an updated pump as soon as I caught this leak, but there was oil covering my transmission and my clutch started slipping at WOT within a matter of days. I only have driven about 500 miles with my stage 2 tune, but I'm not ruling the tune out as the cause by any means.

I don't believe it does. At least not in my experience. I have at least this pump leaking on my tranny currently with no slipping on an OEM clutch with 160k.

[Hugh@EuropaParts]

Hugh, is it possible for oil to contaminate our clutches when this leak occurs? I bought an updated pump as soon as I caught this leak, but there was oil covering my transmission and my clutch started slipping at WOT within a matter of days. I only have driven about 500 miles with my stage 2 tune, but I'm not ruling the tune out as the cause by any means.

Hey! The leak shouldn't have anything to do with a slipping clutch.

[Theiceman]

I applaud aviator for his efforts and I agree with the proper replacement parts this should not be an issue . I used some very expensive sealent I used for my Porsche rebuild and its holding well so far on year two ( Loctite 574 I believe ) . I replaced both the vacuum pump o ring and the sealing ring against the head.
The problem is the very back oring was difficult to get a read on as it has deformed over the years. I think best bet might be to measure and get one a couple sizes under and a couple a couple sizes over to nail it on the first try.
I get mine at oringsandmore

[zzzz05725]

Thank you guys for the responses

[alexcruncha]

Hi Guys,

I too saw the kit for sale on ebay and Amazon from RKX i think. As I am in Europe it would have cost me around 40 GBP to buy it and get it shipped so i decided to do the rebuild myself and source the o-rings from a specialist o-ring supplier.

I understood the RKX kit is essentially 4 o-rings. 2 of the orings are standard o-rings available from Audi that bolt the E version and F,G and H versions to the head. The other 2 are for the backplate and also for the plastic port, both of which are not available via official channels and as far as I can tell the sizes arent posted online anywhere.

So, I proceeded to order a second hand G version pump and disassembled it in order to try and gauge the sizes required.

Its important to understand at this point that the pump can leak from the following 3 locations:
1. Pump to head o-ring (the one that comes in 2 sizes depending on version and readily available from Audi; which have Audi part numbers 06D145117A and 06D145117 respectively)
2. Backplate o-ring (the one unavailable)
3. Plastic port (also unavailable)

Most people that are looking into this might think it only leaks from the backplate but after close examination I tend to believe all 3 seals need to be replaced in order to provide a fix. This would explain why people have recurring issues (especially if people didnt realise the port comes off by depressing the 2 plastic clips, which is a bugger to remove btw).

When I dismantled the G version pump I noticed all o-rings were completely flattened and I saw evidence that oil could have been leaking from all 3 o-rings (due to dirt build up in certain areas). So that means I was probably sold a leaking unit on ebay so good job I decided to rebuild it.

I found the backplate o-ring very tricky to measure as it is not fitted into a round slot so had warped. The others not so bad. Nevertheless, I printed out several potential sizes on a sheet of A4 paper and was able to gauge the sizes quite well. Here is what I found:

ID = Inside Diameter and CS = Cross Section

Backplate size is 94mm ID x 3mm CS (I order one, it arrived and it fitted perfectly so I was lucky)
Plastic port size is 19mm ID x 2mm CS (I discovered this after ordering one with 20mm ID and it was loose - the 19mm ID is on order and not yet tested but I am 95% sure it will be correct)
Pump to head on F,G,H pumps is 56mm ID x 2.5mm CS (as published in many places online under the Audi P/N: 06D145117A... I actually found this size was a tight fit and left 0.5mm space on the outside of the oring in the o-ring slot but I believe this is how its meant to be looking at photos)
Pump to head on E version pumps is 53mm ID x 2mm CS (as published in many places online under the Audi P/N 06D145117)

Important that VITON / FKM material o-rings are purchased as other o-ring material will not last since this part is exposed to high temperature and hot engine oil. I believe o-rings made from Nitrile and other standard rubbers will fail prematurely.

Once I have finished the rebuild and got it in the car I will confirm all is working well and the above sizes are correct. Until then purchase at your own risk.

[Joshlc1988]

I bought the rkx kit on amazon and it’s doing well. I rebuilt the pump in March and no leaks yet. I did however ensure the pump flange and cover were flat. My cover was warped a bit. I put valve lapping dye on the rear cover and flange and ran it on over a 600 grit belt sander until square. So far so good!

[aviator79]

...

ID = Inside Diameter and CS = Cross Section

Backplate size is 94mm ID x 3mm CS (I order one, it arrived and it fitted perfectly so I was lucky)
Plastic port size is 19mm ID x 2mm CS (I discovered this after ordering one with 20mm ID and it was loose - the 19mm ID is on order and not yet tested but I am 95% sure it will be correct)
Pump to head on F,G,H pumps is 56mm ID x 2.5mm CS (as published in many places online under the Audi P/N: 06D145117A... I actually found this size was a tight fit and left 0.5mm space on the outside of the oring in the o-ring slot but I believe this is how its meant to be looking at photos)
Pump to head on E version pumps is 53mm ID x 2mm CS (as published in many places online under the Audi P/N 06D145117)

Important that VITON / FKM material o-rings are purchased as other o-ring material will not last since this part is exposed to high temperature and hot engine oil. I believe o-rings made from Nitrile and other standard rubbers will fail prematurely.

Once I have finished the rebuild and got it in the car I will confirm all is working well and the above sizes are correct. Until then purchase at your own risk.

GOOD JOB! Thanks for posting this info I failed to come up with. Unfortunately not seeing 94mm ID x 3mm Viton o-ring on McMaster-Carr. A made to order is $20 so IDK if others can come up with other options or ideally a vendor starts selling kits but doubt would cost less than ebay kit so still stuck with the $30 kit from from RKX ($25 or less now).

[Theiceman]

we just need someone to buy the kit and measure it before they put it in , but this seems an impossible task as those who get them never seem to do this.

[B7TitaniumA4]

I bought the RKX kit too and have had it installed for 5-7k miles so far no noticeable leaks, I also did the cam chain cover seal at the same time. Everything in the kit looked and felt quality and installed perfectly with the help of their video. I have also purchased the PCV blockoff plate from them and it is also of great quality. 👌🏻👍🏻
Glad there is a company out there making repair components instead of having to replace entire “expensive” parts.

[alexcruncha]

GOOD JOB! Thanks for posting this info I failed to come up with. Unfortunately not seeing 94mm ID x 3mm Viton o-ring on McMaster-Carr. A made to order is $20 so IDK if others can come up with other options or ideally a vendor starts selling kits but doubt would cost less than ebay kit so still stuck with the $30 kit from from RKX ($25 or less now).

I live in UK and there are quite a lot of specialist o-ring companies (some of them primarily deal with bearings) that sell all sizes in all materials. Also all sizes and materials are available on eBay uk. 94x3 in Viton and all other mentioned sizes are off the shelf items. I paid less than 5 GBP for the 94 one and around 3 each for the others (in single quantity) but in quantity the price drops drastically. I can get them for around 1 GBP each in all sizes if I buy minimum qty 10 of each size.

Sent from my ONEPLUS A5000 using Tapatalk

[wding2000]

GOOD JOB! Thanks for posting this info I failed to come up with. Unfortunately not seeing 94mm ID x 3mm Viton o-ring on McMaster-Carr. A made to order is $20 so IDK if others can come up with other options or ideally a vendor starts selling kits but doubt would cost less than ebay kit so still stuck with the $30 kit from from RKX ($25 or less now).

Check this
http://www.oringsandmore.com/

I have RKX installed and wish I knew this - not complaining, happy with RKX kit.

[alexcruncha]

Pls ignore post

[b7a408]

Working on this today. Got the pump off but the backplate o-ring I bought in a kit on ebay ended up being too big. Just ordered this one from oringsandmore on ebay.

[alexcruncha]

Working on this today. Got the pump off but the backplate o-ring I bought in a kit from ebay ended up being too big. Just ordered this one from oringsandmore on ebay.

The update with your ebay link should be exactly the correct one according to my experience. Please let us know how you get on with it.

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[Theiceman]

Check this
http://www.oringsandmore.com/

I have RKX installed and wish I knew this - not complaining, happy with RKX kit.

that's my go to orings place too .. just waiting on confirmation of the size on that back cover, let us know if it fits ,,,, , cant wait as its my next project along with oil filter housing ( well, my sons next project, i have a B8.5 engine on a stand )

[b7a408]

Finally finished this job. Here is a summary:

1. A bit ratchet that can fit behind the vacuum pump helps a lot.

https://imgur.com/XTRlNjI

2. Probably best to buy the RKX kit, I got something similar from ebay.

https://imgur.com/hJkJxN3

3. Took some work but I finally got the pump off, replaced the two o-rings, and then put everything back together.

https://imgur.com/OUJjsro

4. This is where the frustration set it. I turned the car on and the brake was as hard as a rock. I poked around and the pump seemed fine, no leaks, check valve looked OK. I disconnected the check valve from the vacuum pump and blew into it, no air passed. I pulled air out of it and it worked. I was ready to take the whole pump off again thinking I did something wrong but decided to put the check valve back on the pump and tighten the hose clamp (replaced the original ear clamp) to a point of breaking. Turned the car on and voilà! break assist is back!

https://imgur.com/U5HSgVS

Let's see how long these new o-rings will work.

[Theiceman]

I think you will know within a couple of weeks for that oring


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[alexcruncha]

Finally finished this job. Here is a summary:

1. A bit ratchet that can fit behind the vacuum pump helps a lot.

https://imgur.com/XTRlNjI

2. Probably best to buy the RKX kit, I got something similar from ebay.

https://imgur.com/hJkJxN3

3. Took some work but I finally got the pump off, replaced the two o-rings, and then put everything back together.

https://imgur.com/OUJjsro

4. This is where the frustration set it. I turned the car on and the brake was as hard as a rock. I poked around and the pump seemed fine, no leaks, check valve looked OK. I disconnected the check valve from the vacuum pump and blew into it, no air passed. I pulled air out of it and it worked. I was ready to take the whole pump off again thinking I did something wrong but decided to put the check valve back on the pump and tighten the hose clamp (replaced the original ear clamp) to a point of breaking. Turned the car on and voilà! break assist is back!

https://imgur.com/U5HSgVS

Let's see how long these new o-rings will work.

I see in a previous post you ordered an individual 94mm x 3mm VITON oring. Did you receive it and did it fit fine?

[Theiceman]

I see in a previous post you ordered an individual 94mm x 3mm VITON oring. Did you receive it and did it fit fine?

That's what I want to know too ,, the fit and function of that last oring seems to be evading us !!

[b7a408]

I ordered it from oringsandmore on ebay and they didn't provide a tracking number for a few days. I contacted them and they said that it was out of stock and would let me know when it arrives and is ready for shipping. I decided to cancel the order. Yesterday I noticed that my brake booster wasn't working 100% again. Today I took the pump off, left the new 56 mm o-ring on, and put back my old, original, backplate o-ring. My brakes are working fine again. I ordered a new pump just in case this solution doesn't work. I'll monitor the back of the engine to see if oil leaks.

[alexcruncha]

I ordered it from oringsandmore on ebay and they didn't provide a tracking number for a few days. I contacted them and they said that it was out of stock and would let me know when it arrives and is ready for shipping. I decided to cancel the order. Yesterday I noticed that my brake booster wasn't working 100% again. Today I took the pump off, left the new 56 mm o-ring on, and put back my old, original, backplate o-ring. My brakes are working fine again. I ordered a new pump just in case this solution doesn't work. I'll monitor the back of the engine to see if oil leaks.

I see, so you ended up working with o-rings bought on ebay that were sold specifically for this purpose (but not RKX ones). You then found the brakes werent boosting properly so removed the pump and put back the original seal on the back plate and all is now OK. Hmm I see so you didnt have luck then.

Well, I have just installed the 94mm x 3mm VITON seal for the backplate and the 19mm x 2mm VITON seal for the port. Seem to be a perfect fit although I found the port oring a little tight to insert but I got it in easily by pushing the pump down on the port while it was on the floor.

Since I rebuilt a unit I purchased from ebay my original pump is still on the car. I just attempted to remove the original pump and put this rebuilt one on but I gave up as on my Audi A4 B7 cab I didnt have enough room to undo the torx bolts and it seems I need to remove a bracket held on by a spline bolt (M bolt) to get to one of the torx bolts and I dont have one of those... so I gave up for the day. Looks like i will need to get the correct spline/M bit and also a smaller wrench similar to the one in the photos you posted.

Once I do get it installed I will post my results although may be a little while as I am busy the next couple of weeks.

[b7a408]

The ebay o-ring for the backplate was too thick. The backplate wouldn't fit flush against the pump with the ebay o-ring. Here is the link for the set I bought on ebay that will help you with the bolts. I recommend this ratchet to help you access the back of the pump.

[alexcruncha]

The ebay o-ring for the backplate was too thick. The backplate wouldn't fit flush against the pump with the ebay o-ring. Here is the link for the set I bought on ebay that will help you with the bolts. I recommend this ratchet to help you access the back of the pump.

Thanks very much for the links. Yes exactly what I need I will get them ordered.
Thankfully I didnt have an issue with the thickness of the o-ring i used for the backplate. I will update you.

[Theiceman]

so what happened here are we going with the 94mm by 3mm or is it too thick and causing binding ?

I decided to do some of my own experimenting ...

This is what I ordered..

Viton®/FKM O-ring 94.92 x 2.62mm Price for 1 pc

1
$1.05
$1.05
Viton®/FKM O-ring 94 x 3mm Price for 1 pc

1
$4.90
$4.90

Will update you guys on what comes of it.... as it would be nice to put a nail in this coffin once and for all

[Theiceman]

Thanks very much for the links. Yes exactly what I need I will get them ordered.
Thankfully I didnt have an issue with the thickness of the o-ring i used for the backplate. I will update you.

well unless you have put it in the car and tested it you don't really know this , and if I read it correctly you have not put it in the car yet. The vacuum pump are machine tolerances as it is trying to create a vacuum , if even a small piece of that rubber squeezes out into the sweeper area for the pump you will get b7a408's symptoms.

If you have put it in the car and all is well please report back. Torquing down of that back cover in the correct sequence is also important, to evenly push down the oring... I would personally use syl glide to make sure it moves into position easily and does not distort on torqueing.