Impeller Replacement for Cummins 370B in 32+2

[Bob_Lee]

To reach the pump I remover the throttle bracket and cable. I removed the inlet and outlet hoses from the raw water pump. Removed the cover plate and pried out the old impeller with immense difficulty. Caught the key before it fell into the bilge. Removed the fuel cooler pipe and hoses from the aftercooler and tranny cooler backflushed the system to remove the nasty impeller bits. Found some in the feed hose too. Now the reassembly.
Lube up the new impeller, twist counter clockwise as per manual and GOOD GRIEF. I spent an hour on my belly getting sore at arms length trying to fit that slimy bugger into the housing. There is no way to get the leverage to push and twist with the fuel tank where it is.
Has anyone found an effective way to replace the impeller in the 32+2 with the 370B Cummins. My dock buddy's Fortier has the water pump in plain view and he can change his impeller in ten minutes. What was Albin thinking with this setup? I have no clue how I would do an emergency repair at sea with this arrangement.

I have a bruise on my chest from the project too.

[Pitou]

I also have the 370B in my 28 TE. PITA to get to water pump. I understand. I have been able to become a pretzel and access the pump and just remove the cover plate to remove the impellar. My pump is a Sherwood and they make a key/wrench that screws into the impellar that makes removal alot easier. I ordered my first impellar from Cummin's and glad I did as they convinced me I needed the wrench. If you don't have one get one. Preventative maintainance dictates replacing every other year. The toughest part working on boats seems to always be how to get yourself configured to do the job. I always have someone on hand to pull me out if necessart / 5ft 9 in 180 lbs / not too big, but not too small!

[Bob_Lee]

Does the Cummins impeller wrench compress the vanes? Is there a generic brand available? Are there local sources like parts stores for such a tool?
Forget tattoos and body piercings. I think a good boater's body alteration should be a second elbow in each arm.

[Mariner]

Good evidence for why it's recommended that the impeller be replaced yearly.

[Pitou]

The wrench is actually made by Sherwood as well. It is basically a bolt with a t-handle. It turns clockwise and when tightened on the impeller it gives great leverage to pull the impellar out. My impeller is a Sherwood 1700PK and the tool is a Sherwood Impeller Removal Tool 23631. Here is a photo. It made all the difference in my world. A third hand and extra joints would be good Good Luck!

[img][img]http://i149.photobucket.com/albums/s52/ ... 3/tool.jpg[/img][/img]

[Tuxedo]

What do you suppose the difference between the Sherwood wrench and a bolt of the same size turned with a rachet is?

Also, anyone tried compressing the impeller blades (in the proper direction) with a wire tie, inserting the impeller part way, cutting the tie and twisting the rest in?

[Bob_Lee]

Great success!
I used a large hose clamp to squash the impeller vanes about 3/4" from the end. I made sure they were all laying as if I had done a counter clockwise twist. Then I seated the impeller and removed the clamp. I liberally applied several squirts of dish soap. I was able to then twist the impeller to catch the keyway. Then it took a large wrench handle levered against a bolt head on the engine to push against a hammer handle that was pressing against the center of the impeller. In she slid. Wow that was easy. NOT.
Left Warren River about 3:30 on a test run. Pumping good, no leaks.
Test run results for 32+2 with Cummins 370B and 240 gal. fuel, 25 gal. water, 2 people on board:
Best speed ever. Bottom was freshly cleaned and covered with new ablative paint. Prop cleaned and painted with ablative paint.
Ran a tad over 3000 RPM at wide open. 24.1 Kts.
(This was about 100 RPM higher than last fall. I just backflushed the aftercooler, and there were a few barnacles found on my prop at haulout).
2400 RPM was 17 Kts.
(80% is highest recommended continuous cruise speed at Boatdiesel).
2200 RPM was 14.2 Kts.
2000 RPM was 12 Kts.
1900 RPM was 11.1 Kts.
1800 RPM was 10.2 Kts.
At this point the test was stopped due to bird activity and I caught and released 3 striped bass in the calm afternoon sunshine.
About 5 PM, the wind picked up a pretty stiff chop and that was a day.
I am sure glad I dressed all the electrical fittings on the bow thruster. The starboard connection had some corrosion and had developed an intermittent connection. There is a LOT of current going thru that connection, and things can get dangerously hot or inoperative when needed. I disassembled and wirebrushed all the connections and assembled tightly with WD40. It was needed gear with the incoming tide and stiff southeasterly breeze. Singlehanded boating needs reliable gear.
How do these performance figures compare to others?

[Pitou]

The T-Bar on the Sherwood wrench sure makes for a great pull / the threads grip the impeller. Using a bolt and ratchet does not give you anything to pull with. Inserting the new impeller I use Vaseline Petroleum Jelly. Slippery stuff!

[jleonard]

What do you suppose the difference between the Sherwood wrench and a bolt of the same size turned with a rachet is

My last boat had a Cummins 270 with the same pump...I bought 2 bolts (because of clearance issues) and the impeller came right out using the bolts and a open end wrench.
Installation was easy without compressing the blades...a little spray "pam" and some palm pressure while a helper jogged the engine one rev (with connector to the fuel solenoid removed).