Broken screw heads on the impeller cover

Jan 7, 2014
254
Beneteau 45F5 51551 Port Jefferson
My perkins 4108 has 6 screws securing the impeller cover to the pump. The screws were heavily corroded and two of the heads just snapped off. I'll need to remove the raw water pump in order to do the surgery needed to remove those broken screws. I've never removed the pump before. Does anyone know if removing the bolts marked with the arrows in the photo would allow me to remove the pump? Will I need a gasket when reinstalling it?
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Oct 22, 2014
16,079
CAL 35 Cruiser moored EVERETT WA
Tim. Check the fit of the cog and spline. You will need to insert the unit back together when finished. Take photos. So you know how they go back together. I believe the work shop manual for the 4.108 speaks to the disassembly and reassembly of the pump.
 
Dec 25, 2000
5,045
Hunter Passage 42 Shelter Bay, WA
A couple of the bronze machine screw heads on the 2GM sea water pump impeller cover sheared. Was able to remove the studs and replaced all with SS marine screws.
 
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Nov 24, 2014
130
Catalina 310 Staten Island
My perkins 4108 has 6 screws securing the impeller cover to the pump. The screws were heavily corroded and two of the heads just snapped off. I'll need to remove the raw water pump in order to do the surgery needed to remove those broken screws. I've never removed the pump before. Does anyone know if removing the bolts marked with the arrows in the photo would allow me to remove the pump? Will I need a gasket when reinstalling it?
View attachment 194347
Maybe it's just my eyes, but those bolts don't appear to be broken. The one on top looks rounded off a bit. For that reason, I use six point sockets and wrenches over 12 point. Like they say, it is better to be tried by six than carried by twelve
 
Jan 7, 2014
254
Beneteau 45F5 51551 Port Jefferson
Maybe it's just my eyes, but those bolts don't appear to be broken. The one on top looks rounded off a bit. For that reason, I use six point sockets and wrenches over 12 point. Like they say, it is better to be tried by six than carried by twelve
the arrows are pointing to the pump bolts- they are fine. the issue is the bronze screws to the impeller flange at far right.
I need to remove the pump to drill out the screws. my original question was are the arrows pointing to the correct bolts to remove the pump. I still have not addressed this. so far no leaks and the impeller is old but still working. I have to do it before I take it on a cruise though.
 
Nov 24, 2014
130
Catalina 310 Staten Island
the arrows are pointing to the pump bolts- they are fine. the issue is the bronze screws to the impeller flange at far right.
I need to remove the pump to drill out the screws. my original question was are the arrows pointing to the correct bolts to remove the pump. I still have not addressed this. so far no leaks and the impeller is old but still working. I have to do it before I take it on a cruise though.
I think I need new reading glass more than you need a new pump. I focused all my attention on the two arrows and ignored the rest of the shot. Speaking as a hobbyist photographer, it would have been helpful to include a shot pointed straight at the pump. The stripped bolts would have been more visible. If you don't have the engine cowling in your way ,and you have a steady hand, you might be able to drill out the bolts while the pump is still attached to the engine, otherwise remove those screws, and take the pump home. Removing the hoses first should make the job easier, and like I said before, six point sockets are preferred to avoid rounding over the bolts If you have access to a drill press, use it. get a set of cobalt drill bits in 1/64" increments, and starting with the smallest size drill out the bolt, being careful to center the bit, and increase the bit size one step at a time. When the thickness of the remaining metal is less than 1/16 of an inch, you should be able to remove the remaining piece. A little PB blaster and heating the surrounding metal should speed up the process a bit. I would avoid heating up a brass or bronze bolt directly, as its melting point is much lower than steel, and you might inadvertently "weld" it to the surrounding metal. I made the same mistake trying to remove a broken brass bolt from my heat exchanger, and posted a thread about it
 
Jan 7, 2014
254
Beneteau 45F5 51551 Port Jefferson
thanks for the advice. I can't really get access to it while it's on the boat. I hope that with enough pentrating oil and luck that the screws will start turning once I start drilling. the back is open so the may go straight through.
 
Nov 24, 2014
130
Catalina 310 Staten Island
thanks for the advice. I can't really get access to it while it's on the boat. I hope that with enough pentrating oil and luck that the screws will start turning once I start drilling. the back is open so the may go straight through.
Could be a blessing in disguise. You might be able to through bolt it.
 
Jan 7, 2011
2,907
Oday 322 East Chicago, IN
The broken screws are to the Right in the photo…the ones with the arrows are the ones the OP holes will allow him to remove the pump (presumably so he can work on the broken screws on a bench or to replace the pump).