TRNW-2: VW O9G mysterious leak

[Steve Everett]

 This one is bolted on to the top of the bellhousing , round, attaching
bolt through the middle, two coolant hoses

   Steve

On Tue, Dec 16, 2025 at 3:27 PM pat schulte <zzyzxpat at gmail.com> wrote:

> The usual difference is whether the cooler is remote or bolted on as I
> recall.
>
> On Tue, Dec 16, 2025 at 12:12 PM Steve Everett via trnw2 <trnw2 at trnw.net>
> wrote:
>
>>  We put dye in the fluid and finally verified where its leaking from, the
>> crease where the arrow points,  there apparently is a crack there , can't
>> see it with your naked eye, but the dye was seeping from that crack, same
>> place the other bellhousing was apparently leaking from,  we're going to
>> see if we can get it tig welded by a machine shop locally
>>
>>     there is a pressure passageway on the other side of that crease,
>> that is fed by a passageway on the pump body , I've since discovered the
>> valvebody was replaced when it was originally built, there is more than one
>> valvebody for these units,  I don't know if there is a difference in
>> pressures or variations that might explain this ?  I know there are a
>> couple of holes different between VB's relating to lube supply ?
>>
>>    Steve
>>
>> On Tue, Dec 16, 2025 at 2:48 PM Donald Day <trnsmaster at verizon.net>
>> wrote:
>>
>>> If bell is porous clean good then coat with epoxy
>>>
>>>
>>> Sent from the all new AOL app for iOS
>>> <https://aolapp.onelink.me/eG2g?pid=NativePlacement&c=US_Acquisition_YMktg_320_EmailSignature_AttributionDL&af_sub1=Acquisition&af_sub2=US_YMktg&af_sub3=&af_sub4=100002473&af_sub5=SentFromNewAOLApp__Interstitial_&af_ios_store_cpp=ce85ce34-ad0f-4811-a92b-a172743b064e&af_android_url=https%3A%2F%2Fplay.google.com%2Fstore%2Fapps%2Fdetails%3Fid%3Dcom.aol.mobile.aolapp%26listing%3Demail_signature_attribution>
>>>
>>> On Tuesday, December 16, 2025, 10:24 AM, Steve Everett via trnw2 <
>>> trnw2 at trnw.net> wrote:
>>>
>>>   I have an 09 Jetta with a O9G , originally built at another shop, 2
>>> months after being built it had a small leak from inside the bellhousing,
>>> small enough that sitting running after 5 minutes there will be one drop at
>>> the inspection hole at the bottom of the bellhousing,  when you look up
>>> inside that hole the fluid seems to be seeping from the right side up
>>> inside the bell,  we pulled the unit, and fluid appeared to be coming from
>>> around the uppermost bolt on the right side,  (red dot in picture
>>> attached)  I removed the bellhousing, cleaned everything, resealed the bell
>>> and used silicone on all the bolts,  reinstalled unit and still had the
>>> leak,  pulled again,  this time I thought maybe the case was porous in the
>>> are above and to the left of the bolt, as fluid appeared to be in that
>>> area,  I cleaned everything with brake clean, coated that area with JB
>>> weld, resealed the same bolt again, installed a different converter,,,
>>> installed unit,    same leak again,
>>>        took a week or so for us to find another unit,  removed
>>> bellhousing from core unit, cleaned and resealed everything related to the
>>> different bellhousing,   reinstalled,   still have same leak,
>>>
>>>   Different bellhousing, changed attaching bolts the last time around,
>>> using ultra grey silicone to seal everything,  plenty of silicone on all
>>> the bolts, changed converters once, ( fluid is not all over inside of
>>> bellhousing , only on right side, so I don't believe its converter related)
>>>
>>>   only explanation would be two different bellhousing being porous in
>>> same area ?    in the picture attached the fluid originates in the area
>>> where the red dot is
>>>
>>>  Anyone ever seen something like this ?
>>>
>>>    Steve
>>> This message was sent from the TRNW Technical Discussion Forum (trnw2).
>>> You were sent this message because you have subscribed to our mailing list.
>>> If you don't want to receive these emails from TRNW in the future, please
>>> unsubscribe here:
>>> https://www.trnw.net/unsubscribe.php?forum=2
>>> TRNW Inc., 2825 Walnut Terrace, Modesto, CA 95355
>>>
>>> This message was sent from the TRNW Technical Discussion Forum (trnw2).
>> You were sent this message because you have subscribed to our mailing list.
>> If you don't want to receive these emails from TRNW in the future, please
>> unsubscribe here:
>> https://www.trnw.net/unsubscribe.php?forum=2
>> TRNW Inc., 2825 Walnut Terrace, Modesto, CA 95355
>
>
>
> --
> Pat Schulte
> AAMCO Transmissions
> Temecula, Ca.
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.trnw.net/pipermail/trnw2/attachments/20251216/606acaeb/attachment.html>