1978 115 Valve Body Trim leaking

[comet424]

hi i have the 1978 115 chrysler outboard.. i got it with a leaking power trim body.. i have tried tighten the 4 stainless pipes going in it but not luck i even tried teflon tape on the threadings.. and one of them doesnt tigthen up what be causing it to leak and i guess the one is stripped can it be fixed? it leaks out of the lines at the compression nuts... other then that this engine runs great

 

[pnwboat]

The seal is between the tapered face of the nut, and the tapered recess in the valve body. There is no sealing surface on the threads themselves. The threaded nut has to be tight enough to to push the tapered sealing surfaces together hard enough to prevent any leak. If the threads are stripped, then it will not seal.

Only way to fix it is to drill out the stripped threads to a larger size and install a brass male/female adapter that fits the larger size on one end, and also fits the smaller fitting from the stainless steel line.

You could also replace the valve body with one that has good threads. There are some reasonably priced replacement valve bodies but they are made in some foreign country and don't last as long as the US made ones. I'm not aware of any new ones being made in the US any more. You could also try the auction sites for a used US made one.

 

[comet424]

hey i tried tighting this morning and had someone look at it as i raised it lowered it.. seems just the back one is leaking.. i tried tighthen and then it doesnt really tighten.. and i can push on the line and she pops off..

now if i drilled out to a bigger size wouldnt i damage the cone shapped insert? and the adapter would you need a piece of line in there to adapt to the con shape?

i looked on ebay it was selling for 270 american so thats 350 canadian for that little unit.. all due to warn out threads...

how was it possible it got worn out

 

[comet424]

i took the unit off at least cleaned it with brake cleaner.. are they supposed to all have copper rings in there? as the last one is the only one that has one

 

[comet424]

here is video as i couldnt post pictures apparently 1 pic is bigger then the limit

here you can see i have a copper ring in this one the others dont... but the one with copper is the one that leaks and pushes out by finger
so could i safetly tap that and a fitting id need a piece of stainless tubing right i dont wanna damage the insert

https://www.youtube.com/watch?v=-zBF5HflE4Y&feature=youtu.be
video isnt the clearest but hope it helps

 

[pnwboat]

They don't come with copper rings/washers from the factory. Looks like someone has inserted a copper washer, probably in an attempt to stop the leak. The seal is made on the cone shaped fitting in the middle of the hole. When you drill it out, it basically destroys the cone shaped sealing surface. It has to be relatively flat, as the end of the brass fitting is may also be flat. You have to look at the end of what ever brass fitting you select to be sure. Regardless, just remember the seal is made by metal to metal contact of the brass fitting against the valve body. The threads themselves do not form the seal, they just apply the pressure necessary to prevent a leak.

The threads are probably not worn out but most likely got cross threaded when someone did not get the threaded fitting started back into the hole correctly. It's a very common problem. Once you tighten the threaded fitting that hasn't been started correctly, it strips the threads.

 

[comet424]

ah ok.. so ill pull that ring out... so when i tap it to bigger size..do they make a brass fitting adapter with a cone shape in it? so since ill loose the cone shape by drilling do i teflon tape the adapater when i screw it in?...ill have to try a car place for an adapter then...

ah thats too bad they did that pain in butt when you gotta fix this...

ill look tommorow for an adapter

 

[comet424]

oh and the o ring is obsolete that goes back up in housing... is there a substitate size i can get specs etc.. or just try to use old o ring

 

[comet424]

do they make metric to sae adapters? i didnt try to drill hole bigger as it was a 3/8-24 threading but the 7/16 size was too big i felt and i was able to tap the hole without drilling with a M10 x 1.25 tap... and she snug do they make a fitting that i need from metric to sae

 

[pnwboat]

I'm not aware of an "off the shelf" metric to SAE adapter. Let me check around and see what I can come up with.

 

[comet424]

ok i appreciate that

 

[comet424]

any luck? i was tempted to try to drill out to 7/16 but my local car parts store says they dont make or sell a 7/16"
as the metric i have threads in the purple size.. but since its got that extra lip not enough threading goes in.. like the SAE ones as it doesnt have a shoulder on the fitting

 

[pnwboat]

Yes, sent you a PM. (Private Message)