Help bad seals on AGP Dual Ball Bearing Turbo

[jeremylee_7]

The Diagnosis:
Hello, i did a boost leak test the other night at the turbo and had a boost leak at the crank case. I then bolted the tester up to the throttle body elbow and poof no boost leak, so from everything i have read it sounds like bad turbo seals.

The Question:
Now i have searched around a little bit and most everything i have read says i need to replace the whole cartridge for like 800-1000 bux.
Does anyone know if they have rebuild kits for these turbos, I really cant afford to replace it at this time.

Thanks for any help/info.

 

[JusMX141]

Ball bearing turbos cannot be rebuilt.


Sorry; you've now learned the #1 reason why I won't use a ball bearing turbo on a daily driver. Sure the bearing cartridge is durable as hell, but every time there's a problem it costs more to repair the turbo than what you could purchase a new (rebuildable) journal bearing turbo for.

 

[romeen]

Your turbo might not necessarily be bad. My understanding is that the turbo seals need oil pressure to seal properly. So it is not uncommon to have some air get past the seals during a boost leak test. I'm not sure if this applies to all types of turbos so maybe the BB ones are different.

If your not getting any blueish smoke out the exhaust and the turbo is working well with no shaft play then you might be ok.

Justin, can you confirm (or correct) this.

 

[JusMX141]

The turbo's seals definitely work on a pressure basis....much like piston rings are sealed to the cylinder wall by the pressure of combustion.

A ball bearing turbo uses a dynamic-type seal on the compressor side, much like the newer journal-bearing Garretts. Older journal-bearing Garretts used a carbon seal capsule which sealed in either direction....pressure or vacuum. If you're installing a turbo on a carbureted application, I believe you must use a turbo with a carbon-type seal on the compressor side or the engine's vacuum will draw oil past the turbo on the compressor side.

As romeen stated above, if you're not seeing smoke or leaking oil, there's nothing to get excited about....however, if you're blowing oil past the seals, the center housing needs replaced.

You should be feeding the turbo from the head with a .030"-.035" restrictor.

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[JDR7919]

I have a Agp Lr3 that I believe is dieing. Its not smoking but making a grinding sound like maybe bad bears. There is also black residue on the back of the housing. I know BB turbos cant be rebuilt but I was wondering if it could be made into a standard chra turbo?