1990 4.3/OMC Water Pump Issue

[justinh03]

This is my first post and I need help! I am totally stumped on this one and any advice is good advice. I will try to give you a general idea of where I am at and what I have already tried.<br /><br />We just replaced the water pump (housing and impeller) as well as the gimbal bearing in my OMC outdrive. So, we submerged the outdrive in a water tank and run the motor but it doesn't seem to be picking up water. We added muffs to try to force water up so we can run the boat and it won't force water up either. We removed the impeller from the housing and try again with the muffs, nothing. We remove the water pump housing completely and can back flush the water passage (run water through the system backwards from the hose that goes into the power steering cooler back out to the water passage at the water pump). We try spraying water directly into the water passage on the outdrive (w/pump removed) and sometimes it will come out up at the power steering cooler and sometimes it won't. Any ideas? I can't understand why we can sometimes get water going up and always get water if we "back flush." Is there a check valve or something somewhere?<br /><br />Thanks

 

[Bondo]

Re: 1990 4.3/OMC Water Pump Issue

Nope,..... No Check Valves,..... Not that I've ever Heard of anyways.......<br /><br />Sounds like there's Left-over broken pieces of an Old Impeller, or other Debris Stuck in there Somewhere,....<br />Have you Looked at the In-coming End of the P/S Cooler,.??..

 

[Bt Doctur]

Re: 1990 4.3/OMC Water Pump Issue

could the power steering cooler be plugged with debris?platic/seaweed,etc.

 

[justinh03]

Re: 1990 4.3/OMC Water Pump Issue

That was my original thought but, we can't consistently get water to come out of the hose feeding the power steering cooler, it is hit or miss there as well. That means that our problem is between the waterpump and there. Does anyone know where to find an exploded view or diagram of the transom mount where the hose flows through the outdrive? Also, the old impeller was in tact, the housing was cracked but we went ahead and did the whole thing while we were there.

 

[pra100]

Re: 1990 4.3/OMC Water Pump Issue

Don't know if this well help or not.The water comes in thru 18&19.18 is a pvc type nipple with threads on one side and barbs on the other.Mine got clogged up there once.I ended up breaking it into getting it off.<br /><br /><br />

 

[justinh03]

Re: 1990 4.3/OMC Water Pump Issue

So is 18 reachable without removing the outdrive again? If I am looking at that right it seems like I should be able to trim the outdrive all the way up and remove it.

 

[pra100]

Re: 1990 4.3/OMC Water Pump Issue

No.It isn't.If you look at stud bolts 82,which there are 6 of,3 on eitherside.That is what holds drive on,with gasket 100.Inside this is nut 19,which is also pvc.You have to remove drive to turn nut.<br />Now I'm not saying that is your problem.It was just a problem I had.<br />This gust gives you a view of the way the water flows through the transom.<br /><br />One other thought.Did you hook up the little hose on the water pump housing?<br /><br />Also have you tried pushing water back through the hose that connects to thermostate housing and goes back to transom?

 

[justinh03]

Re: 1990 4.3/OMC Water Pump Issue

Originally posted by Philip A.:<br /> No.It isn't.If you look at stud bolts 82,which there are 6 of,3 on eitherside.That is what holds drive on,with gasket 100.Inside this is nut 19,which is also pvc.You have to remove drive to turn nut.<br />Now I'm not saying that is your problem.It was just a problem I had.<br />This gust gives you a view of the way the water flows through the transom.<br /><br />One other thought.Did you hook up the little hose on the water pump housing?<br /><br />Also have you tried pushing water back through the hose that connects to thermostate housing and goes back to transom?

Thanks for the help! I just put the outdrive back on Saturday, I wish I had known that was there to check, but I didn't even know about this problem until after I put it back on. I have hooked water up at the thermostat housing and pre-powersteering cooler, it ALWAYS comes back out. We only have the problem intermittently getting it to go up. That is what is so confusing about this, it seems like if it was clogged we would have problems in both directions, instead, we only get it sometimes in one direction.

 

[Donald Terrell]

Re: 1990 4.3/OMC Water Pump Issue

justin, I had my power steering cooler bust open, I supose I had left water in it and it froze. My son and I started the engine with the muffs on and he said"Daddy I see water leaking" he was 5 years old at the time. Sure enough water was pouring from behind the engine, that is when I found out I had the fluid cooler. It was a b*@#h to get to, had to remove exhaust down tube. It was mounted to the rear of the engine 4.3 V6 cobra. As I was removing it, I found these two pieces of rubber, first thought they were somehow inplace behind the bolt holding the cooler on. I was able to take my cooler to a local radiator repair shop for 25.00 had it repaired. Then I decided to change my impeller and it was missing two blades. Okay, that is what those pieces of rubber were, they were blown out of the busted cooler. I know you said that your impeller had all its fins, but if one were in there from a prior incident it could explain why you can sometimes get water to flow up if there is something in the cooler or lines that could flex or move. My skills or knowledge couldn't compare to Btdoctur's or Bondo's but my experience was their first ideas. Welcome to Iboats Forum! Donwon