Hydraulic system seals

alan cordeiro alancordeiro at comcast.net
Thu Dec 29 12:04:26 PST 2011 

When I did mine (on two different cars) the first time, I did not know about 
the "drag-link" bit. I found a masonry bit at Home Depot that was 3/4" dia 
in the shape of a cross.
I ground off the tip to the right shape on a bench grinder...and used an 
impact driver.

The shaft seal has no real pressure to speak off...I have never seen one 
leak from there...its always the seals under the cross shaped head bolts. 
There are two other seals that need opening the whole pump for (split it in 
half) , I also did those whenever I did the overhaul. The first time I used 
the Audi kit from Carlsen Audi, the second time from SJM>

Alan
----- Original Message ----- 
From: <PeterBergin at aol.com>
To: <b.benz at charter.net>; <sajanesick at bellsouth.net>
Cc: <200q20v at audifans.com>
Sent: Thursday, December 29, 2011 2:49 PM
Subject: Re: Hydraulic system seals


> When I did it, I ground the corners off a 1 inch drag link socket and put
> it on my hammer type impact, usually they come loose with one or to firm
> strikes.  Very easy!
> Pete
>
>
> In a message dated 12/29/2011 1:17:07 P.M. Central Standard Time,
> b.benz at charter.net writes:
>
> If  coming from underneath is most probably coming from one of the
> cylinder heads. Just replace the  O-ring sealing the leaking  cylinder
> head. Or remove and replace O-rings under all 8, 2 in the  front row
> for the PB and 6 in the second row for the PS. No need to  open the
> pump any further.
>
> These heads are needlessly very  tight if not previously removed.
> Bentley says to use a drag link  socket driver, but easier with a
> small cold chisel tapping around in  the CCW direction to break it loose.
>
> When replacing no need to tighten  any more than with a big screw
> driver, won’t seal any better. ZF  used the wrong O-ring, why all the
> sealing problems. Must seal on  the ID of the housing bore, not on the
> OD of the head. use a generic  2-018 O-ring, available from any
> bearing or seal  shop.
>
> Bernie
>
>
> On Dec 29, 2011, at 9:59 AM, SAJanesick -  Bellsouth wrote:
>
>> Bernie,
>>
>> Thanks for the info on  the Nitrile.
>>
>> The pump has a substantial leak, about a drop a  second while
>> running at idle, from underneath and not from the  hose fittings.  I
>> lose about 3 ounces a day just in  running around town so something
>> must be fixed.  Green  blood is too pricy to waste.
>>
>> I considered rebuilding it  myself, but didn't really have a way to
>> bench test it to 2100  psi.  I figure let someone with more tools
>> and expertise  at it.
>>
>>                 - Steve
>>
>>
>> ----- Original Message ----- From: "Bernie  Benz" <b.benz at charter.net>
>> To:  <PeterBergin at aol.com>
>> Cc: <sajanesick at bellsouth.net>;  <200q20v at audifans.com>
>> Sent: Thursday, December 29, 2011 11:34  AM
>> Subject: Re: Hydraulic system seals
>>
>>
>> Your  nitrile O-ring is just fine.
>> Don’t have your pump rebuilt unless  something is wrong with it. DFWAB!
>> Careful with Audi rebuild kits,  they use the wrong O-ring for the
>> cylinder heads.
>>
>>  Bernie
>>
>> On Dec 29, 2011, at 8:14 AM, PeterBergin at aol.com  wrote:
>>
>>> I have rebuilt my pump on my old 200 twice.   Bought a seal kit
>>> (cheep)
>>> from SJM)  did  not do the shaft seal behind the pulley.  Need to
>>> get a drive
>>> link socket and an impact wrench to get  out the round plugs from
>>> the pump.
>>> Kit is  just a bunch of O-rings and seals. Not a hard job, less
>>> than 2 hours
>>> the first time.
>>>
>>>  Pete
>>>
>>>
>>> In a message dated 12/29/2011  10:01:41 A.M. Central Standard Time,
>>> sajanesick at bellsouth.net  writes:
>>>
>>> I  recently lost a seal where the high  pressure hose attaches to the
>>> hydraulic  pump.   According to the VagCat board drawings, there
>>> appears  to be
>>> different size seals depending on which hose is  attached.  I've
>>> matched the
>>> size,  but I am concerned about the O-Ring composition.  The seal
>>> that blew
>>> out was a reddish orange seal versus the  darker brown seal that
>>> is  used on
>>> the  hose from the hydraulic reservoir.
>>>
>>> Since it was over  the  holidays, I just picked up a generic O-Ring
>>> assortment  from Harbor Freight and  indeed found the right size
>>> that seems to be
>>> sealing with no apparent   leaks.  The O-Rings are black and
>>> package states  that
>>> they are made  of  Nitrile and resistant to oil,  grease, etc.
>>>
>>> Does anyone have  any experience of  using black Nitrile O-Rings
>>> within the
>>>  hydraulic hoses  fittings?  I've been told that Audi often uses  very
>>> specific O-Rings of  different color and material for  different
>>> applications.  I
>>> have not  gone  to the dealer yet, but I could still get by there
>>> today or
>>> tomorrow.  In  the meantime, I  travel with wrenches, O-Ring
>>> assortment,  towels
>>> and as much  Chf11s as I can get my hands on - just in  case.
>>>
>>> Also, I'm looking at  having the hydraulic  pump rebuilt by LARES
>>> http://www.larescorp.com/index.html  up  in Minnesota.  From what
>>> I  can tell, they  look
>>> like they know what  they are doing, but I thought I'd  check to
>>> see  if
>>> anyone has any  prior  experience with them.
>>>
>>>  Thanks,
>>>
>>> - Steve Janesick
>>>  sajanesick at bellsouth.net
>>>  _______________________________________________
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>>
>
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