1996 5.7l EFI with Bravo 1 overheating immediately.

[thumpar]

Re: 1996 5.7l EFI with Bravo 1 overheating immediately.

I was just inspecting the old parts to see if I could figure out why it failed so quickly. I found that the plastic piece that is in between the 2 out ports had broken off. It left about 1/4" still on the housing. I am guessing that the impeller caught on that as it was spinning and ripped apart. It is a pretty sharp edge.

 

[HT32BSX115]

Re: 1996 5.7l EFI with Bravo 1 overheating immediately.

I was just inspecting the old parts to see if I could figure out why it failed so quickly. I found that the plastic piece that is in between the 2 out ports had broken off. It left about 1/4" still on the housing. I am guessing that the impeller caught on that as it was spinning and ripped apart. It is a pretty sharp edge.

My (plastic) housing cracked after only a few years of use (I think I included my thread on teh problem)

That's why I went to the Hardin Marine stainless steel housing. That'll never happen again......

Do you run your boat in Roosevelt Lake??

 

[thumpar]

Re: 1996 5.7l EFI with Bravo 1 overheating immediately.

Normally we run on Long Lake that is part of the Spokane river and it feeds into Roosevelt. I would like to get to Roosevelt next year now that we have a boat big enough for those waters. When the problem happened we were on on the Snake.

 

[HT32BSX115]

Re: 1996 5.7l EFI with Bravo 1 overheating immediately.

I still don't really have a good reason why my housing cracked.

It was an after market housing/pump kit I installed in 2006. It worked flawlessly for all those years, I replaced the impeller twice in those years. I spent about 10 days at Lake Shasta in July and it worked fine until the last day.

Actually the last few min, when I motored over the launch ramp and noticed water coming out of the bilge pump discharge. When I looked back under the hood, I saw water spewing out of the pump via a big crack in the side of the housing.........

Cracks and broken pieces are probably a disadvantage of using plastic.........Ain't gonna happen now ! :thumb:

 

[thumpar]

Re: 1996 5.7l EFI with Bravo 1 overheating immediately.

I just went with the plastic replacement for now because it was in stock local. We are running out of time for boating and wanted to get it up and running again. I still want the stainless pump housing. Next time I change the impeller I will just order that kit. I noticed that the fittings from the hoses are just tapped and need fittings. Hardin wanted $25 each for them. Did you use theirs or source them somewhere else?

 

[HT32BSX115]

Re: 1996 5.7l EFI with Bravo 1 overheating immediately.

Hardin wanted $25 each for them. Did you use theirs or source them somewhere else?

Yeah,

I didn't think I'd want to buy theirs either. I just used a couple of brass hose-bibs and a 90 degree brass pipe "ELL" & nipple from McClendon hardware. those are 1" NPT fittings......... even brass is pretty expensive.

There is a problem with standard brass fittings though. They BARELY fit even after I cut and re-threaded the fittings a bit. the fit is VERY tight with the engine mounts. (I don't know how much room you have there with the 5.7l engine)

I also thought about using PVC. They're pretty rugged and probably would be adequate.........I might worry about them breaking though.....


The Hardin Marine elbow might be the best choice because it's a rather "close-in" "ELL" and shouldn't even come close to the engine mount.


Also, if you have a hose that runs under the engine (you have cool fuel?) from the pump discharge (like my 454) , consider putting a plastic TEE in the line that is at the lowest point of the hose.

I got a heavy plastic TEE with hose bibs on each end and a (1.5" pipe) threaded middle so I could put a plastic plug in it to easily remove. That way you can unscrew the plug and drain any water that might be in the hose at the lowest point.

I even considered putting a plastic (PVC) ball valve at the TEE (instead of a plug) so I could reach in and open the valve for draining, but the plug works well if you just put some (2-4-C etc) grease on the threads and don't tighten it too tight.

 

[Slide]

Re: 1996 5.7l EFI with Bravo 1 overheating immediately.

It drives me crazy how such a critical piece like the water pump can fail so easily. If those impellers run dry at all they pretty much destroy themselves. I was recommended to try a Globe "indestructible impeller" after some impeller adventures of my own:

https://www.gcsmarine.com/store/index.asp?show=pdet&pid=198

Pricey but they seem well reviewed, and I am going to order one next time I replace my pump. This plus the stainless steel assembly should result in a bulletproof cooling system.

 

[thumpar]

Re: 1996 5.7l EFI with Bravo 1 overheating immediately.

It drives me crazy how such a critical piece like the water pump can fail so easily. If those impellers run dry at all they pretty much destroy themselves. I was recommended to try a Globe "indestructible impeller" after some impeller adventures of my own:

https://www.gcsmarine.com/store/index.asp?show=pdet&pid=198

Pricey but they seem well reviewed, and I am going to order one next time I replace my pump. This plus the stainless steel assembly should result in a bulletproof cooling system.

Interesting find. PPT has it for under $50 so it really isn't too much. With that and the metal housing it should be very reliable. I have never understood why they use such weak parts on something so important.

 

[skydiveD30571]

Re: 1996 5.7l EFI with Bravo 1 overheating immediately.

I guess that don't see a point in reinventing the wheel when a rubber impeller works great for what it's designed for...which includes being wet. Who knows, maybe these other "run-dry" impellers will become the next big thing; but honestly I think they will just create a false sense of security for most people. Replace a normal impeller on regular intervals like suggested and chances are you won't have problems.

By the way, in regards to your question upthread about which way to seat the impeller vanes. They will automatically set themselves correctly once it starts spinning. Congrats on fixing the problem!

 

[HT32BSX115]

Re: 1996 5.7l EFI with Bravo 1 overheating immediately.

Interesting find. PPT has it for under $50 so it really isn't too much. With that and the metal housing it should be very reliable. I have never understood why they use such weak parts on something so important.

Yeah, I have seen those too. I don't run mine "dry" laugh so I have never had a failure due to that...........................but having said that, I will probably still get one of those

 

[Slide]

Re: 1996 5.7l EFI with Bravo 1 overheating immediately.

I guess that don't see a point in reinventing the wheel when a rubber impeller works great for what it's designed for...which includes being wet. Who knows, maybe these other "run-dry" impellers will become the next big thing; but honestly I think they will just create a false sense of security for most people. Replace a normal impeller on regular intervals like suggested and chances are you won't have problems.

By the way, in regards to your question upthread about which way to seat the impeller vanes. They will automatically set themselves correctly once it starts spinning. Congrats on fixing the problem!

The main problem is that the rubber impellers are not fail-safe at all, they fail violently and unexpectedly without warning. Even a partial flow blockage can unwet the impeller enough to destroy itself. For such a critical engine component I want something way more robust. A run-dry impeller won't change my inspection schedule but it will assure me that I have a robust part driving my cooling system.

Also beware, the impeller will generally correct itself but if it's installed really cattywampus it won't be able to correct and will destroy itself too. I usually disconnect the drive belt and turn the pulley by hand once everything is back together to ensure it's rotating correctly.

 

[thumpar]

Re: 1996 5.7l EFI with Bravo 1 overheating immediately.

I don't think it is really meant to be run dry. It more of a way to show the durability of it. Any little edge I can get I will do. Mine was one of those that failed violently without warning. you an see from the pictures it just blew itself up. All of the pieces where right at the pump in the hose so it wasn't like it was slowly failing. And when installing the new one I might as well put it in the way it is supposed to spin. It doesn't take anymore time to do it right.