Side Plate bracket bolt drip need temporary fix

[ArtJ]

I have isolated a root cause of leaking antifreeze,posted previously.

It is due to a drip coming from the retapped side plate bolt which
holds the alternator bracket. This was snapped off when installing
a new arm the the indigo alternator and ratapped.

I did not notice the leak until now.

The engine has always 20 years at least, probably from begining when new
been fresh water cooled.

At Don's suggestion, I have ordered the replacement side plate with
welded on bracket. But I don't want to mess with this until after haulout,
Because I have trips coming up starting next week
I need a one season temporary fix.
especially since the one I did retap is dripping.

Don suggested using aviation permatex on the bolt and using a solid
bronze washer, not a split lock washer. He also mentioned letting
the aviation thicken over night.

Since the aviation permatex I have had been previously opened, I tried
it yesterday with 10 min air cure. It did not stop the dripping.

The order which I tired was : bronze washer, bracket and bolt.

I had coated the bolt very generously first.

There is antifreeze present at the bracket bolt hole

Any suggestions appreciated

Thanks

Art

[ArtJ]

One suggestion I have already received is to put a neophene o ring
under the flat washer in addition to the permatex.
At present, I plan to liberally coat the bolt and leave it set up overnight
before installing, the installation order would be: o ring, flat washer,
bracket, permatex coated bolt.

[Al Schober]

Rather than the o-ring, I think I'd make a gasket out of a piece of rubber (such as a piece of inner tube). I'd put this between the side plate and the bracket. I'm not sure I'd use the washer unless the hole in the bracket is grossly oversize. I think I'd try to get a seal between the bolt head and the bracket using sealant. Also, my sealant of choice for water systems is the blue rtv (also made by the Permatex folks). I'd put a good dollop of this under the bolt head and let the bolt force it into the hole in the bracket. Then the coolant would have to force this out between the bolt head and the bracket before it could leak. Good luck.

Al

[Concord]

Thread Repair

If there is enough bite on the thread to compress the side plate gasket I would try cleaning both surfaces then apply a thin coat of JB weld to the threads of the bolt and the threads in the block and carefully turn the bolt in until it is snugged tight enough to compress the side plate gasket.

If that does not do it the metal around the threads may have cracks allowing the leak.

Having gone through a similar problem earlier this year I would consider ordering the stud kit and changing the side plate. When I did it the whole job only took a few hours and was perfect. See "Spring Fun" for details on our repair.

[Dave Neptune]

Gooooh

Art, listen to Don, he knows what he is talking about. The Av-grade will stick to oily and anti freeze surfaces if you just get them dry. You don't have to get them totally "clean" and oil free as you would with the RTV. The RTV is good when things are fresh but it just lays there and doesn't really seal if not!! Be sure to drain the block down below the level of the offending stud and you should heve no problem if it is just the stud leaking. If the gasket is comprimised there isn't much you can do other than R&R the whole thing. If you do the whole thing use the Av-grade it is far superior.
You can also try making sure that you relieve any preassure build up in the coolant by venting the cap and it will not force the coolant out with preassure just good ole' gravity.

Dave Neptune

[Mark Millbauer]

Follow Don's advice for sure and I suggest you drain the coolant below the level of the bolt, clean the threads in the bolt hole and the threads on the bolt and use either the AV sealer as a thread sealant or the Loctite thread sealer that still allows the bolt to be removable.

If the plate gasket is good, the coolant is leaking through the threads.

Mark
C27
"Solution"

[ArtJ]

Thanks Guys, The gasket is good, because it was never removed.
I may have just tapped the hole a little off center.

I have picked up neoprene flat washers as well as o rings. I can force
either on the bolt. I am going to try the flat neoprene washer backed
up by a metal flat washer with the bolt coated with Aviation overnight,
then assemble.
Thanks guys

Art

[ArtJ]

By the way, the bolt can be drawn up tightlly

[ArtJ]

Problem solved

I fixed the side plate leak today by doing the following:

1. I removed a burr left over from the original bolt (oops) , probably
the root cause of the inability to seal.. Shame on me for not noticing
this, but it is in a dfficult place to see with alternator installed

2. I added a flat neoprene plumbing washer,approx the size of a nickel, which
I reamed out a little with a jackknife and forced over the 1/4 inch
bolt.

3. I used a pice of small diameter tubing left over from plastic bottle installation and siphoned a little antiffreeze (don't drink }from the side plate bolt hole to lower antifreeze level below the hole.

4. I used thickened aviation permatex which i liberally spread over the bolt,
washer and the inside of the bolt hole.

5 No leaks

[Dave Neptune]

Nice

Art, good to hear you stoped the leak. The Av grade is great and keep some in your ditty box on the boat. It sticks to oily parts and stays stuck.

Dave Neptune