Replacing the broken impeller on our Perkins 4-108- oh my - 2010

We were about to leave the (Loews Coronado) Loews Coronado Bay Resort & Spa at about 1:00 pm in San Diego while on a "Baycation". 

The arrow shows a broken off flapper stuck. 

We noticed our engine exhaust did not have any water. Bummer. We started the motor a few more times hoping it would by some miracle make water and we would be on our way. No go.

We have a Perkins 4-108 engine.

We then took a break and decided what to do. We had until 5:00 pm to get going to our next destination or commit to another nights stay. Our next destination (Coronado keys Yacht Club) was a free stay.

So we dug in trying to fix the problem guessing it was the impeller we searched for another one. Being organized a bit but not a lot because the boat is under construction we did find the spare impeller in the engine parts. No gasket though. Thought I once saw it but who knows.

We got the impeller cover off (I had unscrewed it a few months back to make sure it would come off if need be) and put it aside.

Old impeller

Wire tie on impeller.

We then removed the impeller. It was missing all 12 flippers. Also the key fell out and into the sea water tube. We had to fish it out with tweezers. That took a while.

We then went on the hunt for the 12 missing flippers so they would not clog up the heat exchanger. We found a couple in the intake to the impeller tube. We had to flush water through the hose that is attached to the tube by way of sea strainer to get them to a position we could remove them with tweezers. The hunt went on. After disconnecting the out hose from the impeller housing which is a pre-formed hose (elbow) we found some more. Some were just ground up rubber. We think we got most of them.

By now it was getting time to make a decision on to stay or not. We decided that we were not going to make the 5:00 pm deadline so we committed to another night at the five star resort. Not a bad place to be stuck but it is a bit $$ for working on the boat.

We then replaced the impeller with the new one. Not an easy task. We first tried a house clamp to hold the flippers in place making the impeller small enough to fit into the hole. No go. We then used a wire tie. Worked great.
Have lots on hand.

We had called a dock mate to get the impeller rotation right. Remember there was not any blades on the old one to go by. He said the flippers follow the shaft. We hit the starter a couple times to see which way the shaft was moving (clock wise) and that showed us which way the flippers should go, following the shaft.

We then hit the starter a couple times to get the key in the shaft in the top position. Then we installed the impeller. After about six tries it went in. The key kept slipping out and getting stuck in the back of the impeller stopping it from going in when it was almost all the way in. Damn it.

The impeller cover with silicone on outside edge and grease on the inside center

So any way the impeller was installed.

We put the cover on with the parts of the gasket we had left and some silicone.
Started the engine up and no water. !!!###
Ok try again tomorrow.

We went to the business center at the hotel and paid for some internet access. We searched the web but no step by step impeller install and tips for the Perkins 4-108! I would have thought there would have been plenty but there was none. Just some ramblings about how dumb the stupid difficulty of it. No help there.

We searched FOGGers but no help there. Then we posted a message hoping for words of wisdom. We need some tech tips.

The next day early we started work on the water problem again. Figuring it must be a through hole clog we removed the house to the through hole valve. It is a steel re-enforced house. Had to cut it off. Opened the through hole and the water poured in. No clog there! We checked the house to the sea strainer and it was clear. Hmmmm.

So we removed the impeller cover. We poured water through the sea strainer to the impeller housing. It came rushing out. No clogging there!

Ok then lets see if the impeller is moving. It should. We turned over the engine and no movement by the impeller!!

We re-installed the houses and then removed the impeller. The key on the shaft had slipped out and got lodged inside the flippers! So the impeller went into the housing all the way but the key had slipped out so it did not spin!!!

Ok lesson learned. Check to see if impeller turns before putting on cover.

So now to re-install the impeller. Well we re-installed the impeller about half dozen more times and the key kept coming out. It was frustrating and we are on vacation and our vacation is supposed to be from boat work!

We decided to call for some help. We thought about using epoxy to hold the key but it would take 12 hours to dry enough to set the key. We did not have any quick dry epoxy. We are on a schedule!

We called Admiralty Marine in San Diego.

They suggested we ding the key on the side and put in place with a pair of pliers. So we put the key on a cutting board and dinged it with a nail punch being careful not to lose it. Then we placed it in the slot and used the pliers to force it in. After a little adjustment the impeller went in and the key stayed in place! We used a wire to check to feel the key was in place.

Now we had no gasket left so we used some silicone in its place. We could have made an emergency one with a paper bag but we were needing to get going.

We check for water and wow did we have water!! Better than ever before. Is that telling us something?

We were getting some leaking from the impeller cover but not enough to worry about. It also was seeping harmlessly into the bilge. The water was not hitting the fan belt or pulley.

We will get Chris at Admiralty Marine a gift card and a thank you for the help. We now will need to get a new impeller and gaskets and a spare key for next time!

After impeller install - Lower left is temp