Procedure for disassembling a vnt-15?

[rabbitman]

I think mine needs a rebuild, oil is blowing into the intake .

Does anyone on here rebuild vnt15's? Is it very difficult?

I've never had one apart so I just want to know how bad I can screw things up if I tear into it. Thanks

[rabbitman]

Too late, I don't think I even ruined anything .



What is this in the center, does it need changing? 'Cause I can't figure out how to get it out.

[rabbitman]

I've never pulled apart a VNT-15.  Assuming it's similar to other turbos, that center part is the turbo seal holder.  It will have a metal ring type seal.  Should push right out of the plate.  Considering how fast it can spin I'd recommend getting it balanced afterward.

Andrew

Yeah I used a bit of force and it came out.

Is that the seal that's leaking now? It filled the turbo and started blowing oil up towards the intake mani.

Oh yeah, I marked the wheels before removal so I'll be able to get 'em on the same. Thanks

[rabbitman]

I just blew in into the breather with the filler cap removed and it is perfectly free.

One little thing I wanted to keep a secret from everyone is that a few weeks ago I wanted to lube the turbo so it wouldn't get dry inside. For some weird reason I wanted it to get oil pressure too .
So I dribbled oil into the feed port and blew compressed air in after it to get it thru. The oil came out in a second so to make it get pressure I plugged the drain hole with my finger and then blew air in again. Right away I discovered that wasn't right, I think air came out around the shaft, not sure though.

At the time I thought they were rubber crankshaft type seals and that they might've popped out, I was wrong about that but now they look fine yet it leaks.

Anyways I hope that didn't wreck it.

[rabbitman]

The oil return is a new handmade job by me . I'm pretty sure it's opened, later if I can get my mouth on it I'll see if I can blow through it.

[rabbitman]

I think it's something like 7/16 inch, I used a pipe elbow and brazed it into the oil pan and the smallest part is where the threads go into the pan. It's for sure not down to 3/8. I meant to run a drill through it to open it up but I forgot.

Here is a pic of it:

[rabbitman]

I saw the way arb ran his drain, up around the engine to the vacuum pump return, and figured if that worked this HAD to work.

What is the correct torque for the nut on the turbo shaft? Thanks

[rabbitman]

Well I blew down into the oil return line with my mouth. It is perfectly clear, it did sorta bubble a bit since the oil level is above the return in the pan.

It was by no means plugged though.

[Rabbit TD]

What's the I.D. of the most restrictive part of the return?  The reason I'm asking is that the turbo seals are never a positive seal.  They will always be able to leak if given the opportunity and to prevent oil leakage, the center cartridge depends on oil slinging and good drainage.  If there are any issues with the oil return that prevents the oil from draining faster than it gets pumped into the turbo it will blast out the turbo seals even if they are brand new.

Andrew

Thanks for that answer on the oil seals.  I always wondered how they worked at that speed and with that much heat and now I see why a good fast drain line is needed

[rabbitman]

Well for some reason it doesn't leak oil anymore.

I completely tore it apart, didn't fix anything and put it back together and it works good.