Opelotus

Did a smoke test on the '84 today, found leaks @ oil fill cap, brake booster vacuum hose, and the idle adjustment screw. Fixed the first two, not sure how to fix the idle screw leak. What seals the threads of the idle screw into the throttle housing?

Opelotus

no ideas?

LGL

It has to be free to turn so sealing permanently wouldn't be a good idea. You might try something like a blob of liquid gasket maker that would seal it until you needed to adjust again.

Opelotus

So there isn't any form of o-ring or seal that is supposed to seal it off? Would teflon tape be safe?

LGL

I would not use teflon tape. It could end up inside.

blown 87

I would use Locktite pipe sealer with teflon, comes in a little tube.
It will not harden.

hacker-pschorr

Yup - great stuff.

In a pinch you can find this at Home Depot:
http://www.homedepot.com/h_d1/N-5yc1...atalogId=10053

User liberally, you don't need a lot.

Imo000

How bad is the leak?

tailpipe

On outboard motors I would use cotton string soaked in non hardening formagasket and wrap it tightly around the threads then thread it back in the hole worked fine for me. OR you could wax up the screw clean out the hole nice then fill the hole with JB weld and put the screw back in till it seats the wax will keep the JB weld from sticking to the screw

WallyP

A small spring to fit the exposed part of the screw, a small washer that is a slightly loose fit on the screw, and a small O-ring that is a snug fit threaded on the screw, pressed to the housing by the spring and washer, might cut the leak to nearly nothing.

Tampa 928s

The question should be how much leakage is acceptable!

Opelotus

Everyone brings up good points - the leak is large enough where smoke from the machine is clearly visible - the leakage scale showed it to be a bit larger than a 0.040" leak. Is this screw supposed to be sealed 100% to begin with, or is there some wiggle room?

Wally - the screw already has a spring on it, if I try the o-ring method would I need another spring?

WallyP

Not if the spring will still work if a thin washer and small O-ring are added.

blown 87

They had to be designed to have some amount of total leakage, from various places, but I would think that any leakage more than what the IAC could compensate for (close) would be the limit.
I have no idea what that would be in CFM.

Maleficio

What's this smoke machine?