Help on setting stuffing boxes and water pump trouble

[ScottyC]

I have 2 questions/problems. This is my first experiance with a boat of this size and complexity so bear with me, we have a 1979 300 express with 454's that has been sitting for 5 years, when we (After unknown countless hours of work) put her in the water the stuffing boxes leaked like a sive and I also had a heating issue in the motor so we pulled her right back out. Someone told me they will swell back up and probably stop, I had already tightened them to snug with a wrench. I fixed a pinched radiator hose and put her back in, not a drop through the boxes and my heating problem was still there. We went about 1 mile to a dock, sitting at the dock the boxes are still not dripping after 5 days in the water, I know this is too tight, my question is how do you adjust them? Snug then losen X amount or ? I think they are suppose to drip a little right? Second troubles is the raw water pump. I rebuilt one with a new body/impellor kit. There didn't seem like I could do much wrong in assembling but most of the rubber fin's got chewed off and some damage to the new housing was done. This in a matter of 4-5 minutes running. I was pretty darn sure they were rotating in the right direction for that motor, the only thing I can figure is a piece of the old rubber was towards the suction side and did it or I screwed up putting it together. My question, is there anything like assembly grease or something that I missed out on that may have done the damage or any ideas what may have caused it? Does the rubber theory sound possible? I have 2 new kits coming now for both motors so any advice would sure be helpful before I make more junk out of good parts. Thanks for any help you can come up with, this has been an adventure but I enjoy the working on it and someday will have a Gem, We love the boat.

 

[ScottyC]

:smt100 I didn't think I would get no answers, am I posting this wrong or ? Any help or suggestions of a direction to look would help, Thanks, Scott

 

[Jimmy Buoy]

Were all just busy boating - that's all!

The thing to watch for with you shaft seals is that there is a limit to tightening the nut. Eventually you no longer have packing material between the shaft and fitting and you end up scoring the shaft. It is normal for these to have a drip about every 30 seconds or so when properly tightened.

The shaft should still be able to be turned by hand or it might be too tight.

Not sure what to say about the impellers except that if some vanes had previously broken off they may be downstream of the pump. Back flush the system if you suspect this.

Good luck.

 

[Air O'Nautical]

You would be smart to change all the flax packing in the stuffing boxes.
This is an easy job with some new tools you don't have yet..
You need an assortment of picks along with a packing removal tool (looks like a cork screw on a flexible shaft).
See the old packing to check for size of the new stuff.
Get "GFO" packing or regular wax.
Time, sweat, and 50ish bucks and your new again.
Tighten only hand tight and then 1/4 turn more as necessary to have a slight drip when the shaft is spinning.

The lube for the water pumps is dish soap.
You cant install the wrong way as the vanes will correct direction when it first starts to spin..
Have fun.

 

[ScottyC]

And I sooooo wish I was on the lake, beautiful weekend and 2 broke boats. Steering on the other one, waiting for parts. I am going to the lake now to work on the 300, my new pump parts will be here Monday. I am going to remove all the hoses from the sea cock to the manifold and from each cooler to be sure there clean. Do you know of any lube they put on so they don't start dry? Maybe should they be primed? Any tricks or cautions would be helpful, don't want to wreck 2 more....
Kinda what i was hopeing to hear about the boxes, I'll just slowly back them up until I get that drip drip going. Thanks a lot for your info. I am in North Central North Dakota and it's not noted for Marina's or mechanic's to talk too.:smt009

 

[ScottyC]

Thank you, Thank you both for this info. I wondered what the packing was made of, I pulled the packing out of the rudders and greased them with water resitant grease thinking that would help but wanted more info for the prop shaft boxes. I am not afraid to work on things just sometimes need more knowledge.:smt038

 

[tobnpr]

Rudder posts should not drip at all, ever.
Shaft boxes should drip slightly only when running, and not at all at rest.

 

[ScottyC]

Thanks for that, I didn't know that. I was at the boat yesterday and the rudders are dry and so was the stuffing boxes. I am thinking I should back them off an 1/16 to 1/8 turn when I run it next time in case I'm too tight, then see if it drips and go from there, sound right?? My hoses had more rubber chunks in them and I discovered what I think is another flaw. The port motor comes from the seacock to the pump, the starboard had a oil cooler between the pump and seacock. It seems like someone changed hose and routed it this way but I can't figure it right that you would want to draw through a restriction (cooler) versus push through it with a paddle pump. Any one know if this is wrong? Thanks for the info it has helped me a lot, Scott

 

[Jimmy Buoy]

The oil cooler should be down stream of the pump otherwise I would think it could restrict flow to the suction side of the pump.

If you think that the prop shaft stuffing boxes are too tight, you can always back them off a bit. If they leak, just tighten a bit each time to find the right spot. Like "Air O Nautical" said, a better route to take would be to remove the collar and old packing and repack the box. That way you would ensure that you are not damaging the shaft.

There are various sites describing this proceedure. Sorry, but I no longer have the links since getting a boat with dripless seals.

 

[ScottyC]

Going to the boat tonight with rebuilt pumps. Will be redoing some plumbing and the stuffing boxes when we get it home hopefully after this weekend on the lake if all goes well. Thanks for the help, We still have a lot of work ahead of us on this but what a boat, we love the old style and think it's well worth the efforts. I will let you know how this turned out. Scott

 

[Saverio]

Hi Scott

I bought the same boat in the spring and like learning as i go on!!!!

i changed the impellers in the pumps also. i'm not sure if your aware but the engines spin in different directions. they are also labeled in back of the pump for direction. the cooler should be on the output of the pump.

do your boat have a/c or gen???

thanks Saverio