Throttle body shaft vac leak?

[iwannadie]

I have noticed a pretty good size vacuum leak at the throttle body butter fly shaft. Its just pouring out, I've been searching and can't seem to find much?

Are there service kits to replace the bushing or bearing? One site suggested just repacking the bearings with grease?

Or, is the best fix a new throttle body?

 

[Agreen]

If you're crafty, you may be able to fix it yourself with some plumbing solder. I did this to a 1964 Johnson outboard carb. The throttle shaft didn't have seals on the shaft, and the bushings were worn badly. I drilled them out as little a necessary to get them round again, then built the shaft up with solder. I chucked it up in a drill press and filed it down until it was the same diameter. Then I polished the shaft, gave it about a 0.0015" clearance between it and the bushing.

It's not difficult, but the tools may be out of one people's reach, and I understand that. That's why I used a drill press and not a lathe!

 

[Ecomike]

I would probably go with a used spare TB. But metal filled epoxy might work. I wonder if greasing the shaft itself would keep the epoxy from sticking to the shaft, and yet stick to the TB? Eliminate any drilling. Are you sure the leak is even a real problem????

 

[Saudade]

How did you determine the leak around the shaft?

 

[Tim_MN]

Is the leak, (which is technically an intake leak, right ?) actually an issue that needs addressing ?

The simple fix is a good used TB.

 

[iwannadie]

Smoke machince show smokes just pouring out. I assume it's a problem since it would be a massive vacuum leak no? It would be the same as a vac leak anywhere else sucking in air? If it was on the intake side of thr TB then no big deal it's just sucking unfilteted air. Being it can suck in air while the TB is closed is bad, I figure.

Maybe I will hook up the vac gauge and see where I am at and try putting a rubbr glove or soemthint over the leak and see if it makes an imact.

Buying a used TB seems to have the risk of putting another leaking one in, how would you test for it without installing it. New TB's are pricey too.

 

[Tim_MN]

The butterfly shaft is on the intake side and vacuum is generated inside the intake manifold, and not at the throttle body. Is the leak a idling/driving/stalling issue ? A used throttle body is less than $25 around here.

 

[Ecomike]

Smoke machince show smokes just pouring out. I assume it's a problem since it would be a massive vacuum leak no? It would be the same as a vac leak anywhere else sucking in air? If it was on the intake side of thr TB then no big deal it's just sucking unfilteted air. Being it can suck in air while the TB is closed is bad, I figure.

Maybe I will hook up the vac gauge and see where I am at and try putting a rubbr glove or soemthint over the leak and see if it makes an imact.

Buying a used TB seems to have the risk of putting another leaking one in, how would you test for it without installing it. New TB's are pricey too.

IMHO, these are not the Droids you are looking for. If the leak rate there was bad enough to be a problem, the shaft would also wobble side to side, which could be an issue at that point. Is the shaft able to wobble side to side? Does pushing it side to side disturb the idle? BY side to side I mean pushing the shaft sideways perpendicular to the hole in the throttle body that acts as a bearing surface. Some leakage there is IMHO probably normal.

 

[ehall]

My old GM TBI has bushing kits available on ebay. Drill out the hole, tap in the little brass bushings, there you go. Kind of a pain actually. I would probably just replace the throttle body since you would have to remove and disassemble for the bushing work anyway. Easier and faster to just put another unit on

 

[kelso1]

You can buy a rebuilt or bored TB for around $130 That would be a easy option and some hp too!

 

[8Mud]

If you don't have a high idle I don't see an issue. If you have to have a vacuum leak this is a good spot.

 

[cruiser54]

You can buy a rebuilt or bored TB for around $130 That would be a easy option and some hp too!

Yes www.strokedjeep.com