Impeller pieces - Backflushing??
 

I have a bunch of missing impeller pieces missing in action. I took off the hoses to the sea water pump and only one came out, now I need to do some back flushing... Which order should I back flush them or doesn't it matter???


On a side note: Merc engineers have got to come up with a better pump system... Volvo looks so simple mounted on the front pulley.. with twins, these merc pumps are a pain in the ass to remove... at least the starboard!!!!

Thanks for your thoughts!

Re: Impeller pieces - Backflushing??
 

I disconnected the water feed hose from the exit side of the oil cooler and hose flushed it watching the water come out the hose that normally connects to the exit side of the raw water pump, not a thing came out and water seems to be backflushing through the oil cooler ok. I notice on the exit side that I am hosing water in, there is like a ristrictor plate with holes in it, is there a restrictor plate on the input side of the oil cooler as well? I can get to the input side of the oil cooler to get the hose off to check for rubber pieces.... any other ideas on what I should take apart to find these pieces.... I don't feel good about putting this back together with these pieces missing..

Thanks!

Re: Impeller pieces - Backflushing??
 

I dont think it's a restrictor. I think you're looking at the tubes the water flows through. The oil is cooled on the outside of those tubes.
I wouls suggest removing the hose between the pump and cooler. Reach in the cooler and see if the impeller pieces are lying in the inlet. I use a long hemostats to pick them out. Not much will make it past the oil cooler, and if pieces do, they will most likely flow out the engine and exhaust.

Re: Impeller pieces - Backflushing??
 

OK, so all the little holes I'm seeing on the exit side of the oil cooler are water tubes so on the input side of the oil cooler, it would look the same. Again, I can't get to the hose connection on the input side of the oil cooler and I'm back flushing a lot of water through the oil coor and it's flowing out the hose at the raw water pump just fine. This has got me baffled, there were a lot of pieces missing from the water pump impeller and I only got one of the broken fins out so far, there are several other large chunks still missing....

Is it possible that even though I'm backflushing the oil cooler, they could still be caught up on the input side of the oil cooler? Argh..... In need of mechanic one foot tall with 6' long arms!!! hehhehehehehheee

Re: Impeller pieces - Backflushing??
 

Yep, been there. They can just sit at the bottom of the cooler inlet with water flowing over them whe backflushing. But when normal flow starts bouncing them around, they can restrict the flow through the cooler.

Re: Impeller pieces - Backflushing??
 

Dammmmmm........ not sure how to get at the back of the oil cooler... welp, here it goes.... send help if I don't check back in!!!!! eeeeeek!

Re: Impeller pieces - Backflushing??
 

OK..... got the dammed hose off the back of the oil cooler and their they were just stuffed in there.... well most of them anyway.... I'm missing two small chunks about 1/2" each yet..... I back flushed the oil cooler again in hopes that the two little pieces would show themselves but nothing. I can't feel anything else in the backside of the oil cooler, is it possilbe they are lodged in there furthur? How far in does the opening go into the oil cooler from the back? Should I get a hanger or something to poke through the water tubes from the front of the cooler???

Re: Impeller pieces - Backflushing??
 

It's about 3" from the end of the cooler to where the cooling tubes start. Keep looking and maybe try backflushing again without the hose on.
The pieces have to be smaller than the tubes to get past the cooler.
Gary

Re: Impeller pieces - Backflushing??
 

Thanks Gary!!! I really appreciate your support through this!!!! I got every last missing piece.... I finally had to use a hanger to dislodge the last ones and they came out with a backflush.... And I thought working on a single engine was bad.... yikes!!! I always keep a loaded spare housing with me.... replacing the pump isn't bad, but getting the pieces out.... I'm going to buy an extra along with my spare and do that port motor right away before it blows!!!!

Thanks again and have a great one!!!!