Manifold leak

[otis71]

I’m fighting with a leaky manifold seal on a ULH and can’t get it fixed. First I tried annealing the brass seals and got the rear to seal and slight leakage on the front. I bought name brand PEEK seals, followed directions and both leaked. Tried the brass again with same results as the first time when I used brass. Ordered new brass but haven’t got them yet. I’ve cleaned and inspected everything. Tried never-seize as well as grease. Nuts, nipples and manifold look true and fit squarely. There is a small gap (1/6”-3/32”) between the manifold and nipple when fitted but the seal should compensate for it. The manifold does have a slight wear spot on the front and rear where the seal goes but the seals are tight.. Can that be the problem? Any help that I haven’t tried is appreciated.
Pictures are of the front spigot.

[Jerry Wieland]

I’m fighting with a leaky manifold seal on a ULH and can’t get it fixed. First I tried annealing the brass seals and got the rear to seal and slight leakage on the front. I bought name brand PEEK seals, followed directions and both leaked. Tried the brass again with same results as the first time when I used brass. Ordered new brass but haven’t got them yet. I’ve cleaned and inspected everything. Tried never-seize as well as grease. Nuts, nipples and manifold look true and fit squarely. There is a small gap (1/6”-3/32”) between the manifold and nipple when fitted but the seal should compensate for it. The manifold does have a slight wear spot on the front and rear where the seal goes but the seals are tight.. Can that be the problem? Any help that I haven’t tried is appreciated.
Pictures are of the front spigot.

Throw the brass seals and use PEEK and never look back. Jerry

[T. Cotten]

Please look at the wear ring from the brass on your spigots, Otis!

Mass-produced PEEK seals would never fit correctly, as they should fit NOS manifolds.

And if you have modern aftermarket nuts, all bets are off on the internal bevel.

Worn manifolds should have the spigots re-cut, and PEEK seals custom-cut to a squeeze-on fit, mated to the nuts.

....Cotten

[otis71]

Who does custom seals? I suspect the nuts are colony because they look brand new.

[otis71]

With no meets near me for 6 weeks is there any acceptable aftermarket nuts?

[T. Cotten]

I pioneered the use of PEEK for manifolds, Otis.

Here is a manifold on the lathe showing the first pass did not clean up the wear..

SPGTCUT.jpg


Note also that I cut seals fatter than the mass-produced seals (on the right), which use brass dimensions:

SEALWDTH.jpgSEaLWDTH2.jpg

Brass had to be thin to arch and compress upon the spigot, but PEEK seals by compliance.

Please feel free to email me direct at Liberty@npoint.net...

....Cotten
PS: I must measure all nuts because the variety, and COLONY's can be as much as six degrees different from OEM!