I was doing a 5psi boost leak test on my 88 GTA tpi
And I found a big vacume leak on my stock 230km tb driver side seal
Does anyone know if it's hard to rebuild it myself and I need a rebuild kit
Or does anyone know a used one
I should have a bbk 58mm one
Ty

It held the 5psi all day
Minus that leak

I had a similar problem. I have a new gasket coming soon.

A leak at the throttle shaft would mean it needs to be rebushed, just like a throttle body on a carb. Not too difficult but can get just a bit complicated. I've never seen a leak at the gaskets concerning vacuum, they tend to seal well. Coolant on the other hand is a problem, but solved easily through bypassing the throttle body.

Bringing this one back up. I am doing a leak test on my Accel 58mm throttle body and can't get more than 7 pounds during my leak test. You can hear lots of air from the driver's side throttle body bolt/spring area. Anybody seal this up successfully? If so, what did you use?

Reamer, bushing, second reamer, assemble. Frequently repair only involves the outboard (left) bushing as the others don't wear much at all.

It's been covered numerous times.

I may be uninformed, but do stock TPI throttle bodies (TB) have seals on the shafts? I don't believe that they do.

I do know that the GM turbo Buick/TTA blow thorough applications do have shaft seals. This is to prevent the loss of boost pressure.

RBob.

Consider vacuum grease. If that seems inadequate, disassemble the TB, counterbore the left side 5/8 x 5/32" deep, and slide on a CR3060 seal. I'd resist the temptation to undercut the throttle shaft to fit an O ring or quad ring, since that could create a weak point.

I just looked this vacuum grease up and have never heard of it. I am assuming I would take the outer bolt off the throttle shaft, pull the spring off and then put this grease between the shaft opening in the body and the shaft right? The reviews say it is sticky, so maybe this may seal similar to permatex #2 non hardening sealant?