Impeller Tricks

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Ty-wraps, also known as cable ties or zip ties, can simplify an impeller replacement.

Ty-wraps, also known as cable ties or zip ties, can simplify an impeller replacement.

At Soundings we know that our readers are boat savvy and well-versed in the magic ways of boat maintenance. One of them, David J. Mahler, e-mailed us a great tip that will easily get an impeller back into its housing:

I read and enjoyed Tom Neele’s article “Down And Dirty In The Engine Room” and can thoroughly empathize with every aspect, from screwdriver drops to contorted one-handed grabs for unseen parts.
One tidbit that I wanted to offer for readers hoping to do their own repairs, whether maintenance or emergency, would be:
When attempting to re-install a rubber impeller, say, into a sea water pump, the easy trick would be to compress the vanes in the spin direction, and hold them down using a series of nylon Ty-wraps.


Just zip the first one over the leading edge of the impeller, about a 1/2 inch from the end. This should suffice to compress the vanes adequately to allow the (already pre-lubricated with Teflon-based lube) impeller to slide into the (already pre-lubricated with Teflon-based lube) pump housing.With the larger impellers like the ones here in our Caterpillar C-12’s I typically run a set of 4 Ty-Raps along the body of the impeller.

As you slide the compressed impeller into the pump body, just carefully snip the inner most Ty-Rap, and be sure to remove the entire wrap, and continue the process until the impeller bottoms out on the wear plate.


Once in, check for tolerance, insert either the (already pre-lubricated “O” ring, or gasket - depending on pump design) and install the (already pre-lubricated with Teflon-based lube) end cover, and screw in with bolts that have been lubricated with non-seize compound. We use the paste copper-based product available from Cat.

I hope this helps — it’s made a world of difference in keeping my engine maintained. Now, excuse me, as I need to have lunch.... in my engine room! Yes, it’s clean.


Thanks again, keep writing the good stuff, and we will keep reading it.


Captain David J. Mahler
USCG Licensed Master
TCS Marine Services Corp.
Bellmore, New York

This letter to the editor was published in the July 2018 issue of Soundings