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1956 Johnson

J

JDBlack

New member
Hey everyone
I've got a '56 Johnson 30 HP RD-18 that I'm trying to get going. I got it fired up today, and of course found out my water pump/impeller isn't pumping water. I'm new to outboards and I've searched several forums looking for the parts I need. I keep reading that there are kits that you can buy, but the closest thing I've found is just buying the individual parts. Trouble is, I'm not sure what all to purchase to ensure I'm doing it correctly. I'd appreciate any information you guys are willing to share. And I apologize if this is a common post, I really did try to search around before posting.

Thanks again!
 
No problem thats why we ae here,Welcome!!I have personally never worked on a engine that old,but there should be a rubber impeller and a plastic casing with a metal inser inside of it,andmabe some o rings.Thats what every water pump i have replaced has.
 
In most cases the parts to replace are the impeller (page 16 part 4)and plate if it is worn or not flat(page 16 part 5). Check the condition of part 2 which connects the impeller housing to the water tube. Replacement is fairly simple. To remove the lower unit locate the cover on the side of the motor (page 14 number 42) and remove the 2 screws. Inside you will see a brass coupling with 2 bolts. Position the gear shifter to expose the bottom bolt for removal with a 3/8ths socket. You do not need to remove the upper bolt. Remove the 6 bolts (page 16 number 13) from the mid-section to lower unit (7/16ths) and the 9/16ths bolt on the back (page 14 number 4). Lower the assembly. Remove the 3 screws retaining the impeller housing to the lower unit. Remove the drive shaft along with the impeller housing and impeller. Be careful not to lose the pin that positions the impeller on the drive shaft. Installation is reverse of removal. Before you put it all back together you might want to consider putting a seal kit in the lower unit. When you put the bolt back in the brass shift rod connector use caution not to cross thread or over tighten the bolt as the threads are fine. If you drop the bolt it can be found by lowering the unit and checking the cavities. Fractions listed for the bolts are the socket size not the dimension of the bolt. A useful item for removal of the bolts and screws in a handheld impact driver that you strike with a hammer. Reduces the number of broken and rounded bolts and screws. Also helps to have a long nose needle nose pliers to hold and position the shift linkage into the brass coupling. Be sure the water tube seats in the impeller housing grommet. As you remove the old impeller check and note which direction the fins are facing. As long as you have the lower unit off you can put a garden hose up to the water tube to ensure there are no blockages in the water system beyond the pump. You should see water coming from the large hole just above the bolt shown as #4 on page 14. There is no thermostat to worry about so water either flows through the system or there is a blockage. Blockages can be caused by insects that have found their way into the unit or sediments that have built up from use in dirty waters or just sitting unused for years. Another great source for help and info can be found at http://www.aomci.org/.
 
Mnobfan, thanks for taking the time to help me with this. I was curious about what was past the impeller and how to check it. Thanks again
 
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