1993 Mercruiser 7.4L Bravo 454 High Temp - Overheating - Sea Ray Sundancer 1993

[djalexg82]

Hello Everyone,

Most of the info here is very helpful and i know what to check for to figure out if it?s the impeller or just blockage in the hose.
My question is can I remove the salt water pump and the 2 output and supply hoses while the boat is in water?
No one seemed to mention if that is ok to do or not. I am a beginner but a fast learner and would like to give this a shot myself
I live on the water so if I don?t need to tow the boat or drive it to the mechanic I rather not

All the help will be greatly appreciated

Alex

 

[littlebookworm]

Re: 1993 Mercruiser 7.4L Bravo 454 High Temp - Overheating - Sea Ray Sundancer 1993

Welcome to the forum. Make sure you have a service manual handy. You can download an original Mercruiser manual from a few sites; just google it. If you have a thru-hull water pick-up with a seacock valve and strainer, you can close the seacock and remove the hoses and pump with no problem (assuming your seacock doesn't leak). You can then pull off the hoses and pump, gettting only the water than was in the hoses and pump in the boat, something your bilge pump can easily handle. If your water pick-up is in the Bravo drive, as most are, and you pull the feed hose off the water pump (check the service manual for which one is the feed and which is the outflow), water will pour into the boat. If you have a bung plug and clamp ready, you can plug the feed hose and stop the flow. Your bilge pump will take care of any water wihich got in. Be aware that, if you are slow or drop the plug or the plug's the wrong size, you could become overwhelmed by the flow of water. If you run into trouble, just stick the hose back on the pump and clamp it. Take a breather and try again. I have heard of mechanics using a cooling system locking hose pliers (not a hose clamp pliers) to squeeze the feed hose closed before removing it, thus minimizing water flow on removal. The bung plug is then inserted and clamped. It's usually easier to remove the hoses after you remove the pump from the engine. The hoses are wire-reinforced and are stiff and difficult to remove. By the way, before you take apart the water pump, mark a white line across the housing, face, and mounting bracket. That makes it much easier to re-assemble the parts with everything lined up properly. Hope this helps, and good luck. Hy

 

[MarkSee]

Re: 1993 Mercruiser 7.4L Bravo 454 High Temp - Overheating - Sea Ray Sundancer 1993

Assuming you've got a similar setup to my 2001 270 'dancer with the 1-piece hard plastic water pump housing, the lip of that fitting measures 1.28 inches and narrows to 1.22 inches. A 1 1/4 inch wide bolt wrapped with a little teflon tape should plug the 2 water hoses nicely. I would also suggest having someone watching just in case you need an extra hand for something.

On the 270, there is no room to just pull the housing off the pulley; have to pull the housing out some while still attached to the pulley to get access to pull the 2 hoses off. This means having to loosen the pulley from the engine block and in my case, I had to remove the pulley altogether. That meant removing the lower water circulating hose which meant more water exiting the block so having some buckets on hand will help.

As mentioned above, before disconnecting anything make a mark across the pump housing, pulley, bracket to aid in proper alignment for reconnecting.

Use a little dish soap on the housing fittings and inside the hoses to help installation of the hoses a little easier which for me meant installing the hoses onto the pulley/bracket first then securing that assembly back to the engine block; absolutely no way to push those hoses on and properly secure them with the stringer in the way.

You can do it but plan on it taking some time, plan on getting wet and read up and watch any videos to help prepare.

Mark

 

[djalexg82]

Re: 1993 Mercruiser 7.4L Bravo 454 High Temp - Overheating - Sea Ray Sundancer 1993

Wow thank you guys so much - that is very helpful. I also asked a Mechanic over the he could not spend too much time with me on the phone but here is something he wrote, after i sent him some pics

Alex,
Yes the raw water has been diverted thru the hull. So that green blue corroded thing is the strainer. The top can be removed to check flow and clean strainer. Check this first then check output pump. No output w good input equals bad impeller. Close strainer remove pump and bring over I will show you how to break down pump. Mp

Now, the crazy part is that the green corroded thing he is talking about has a hoses running through it like a T but those hoses are not connected to the sea pump at all they are leading someplace else and not even to the engine

Now of the sea pump hoses is leading towards a seacock with a huge yellow lever that?s set in upright position, this seacock is right next to the green blue corroded thing he was talking about

so I just want to make sure i am understanding him correctly why remove the strainer if the hoses are not connected to the sea pump just seems strange to me

by the way I do have all the manuals, the person who sold me the boat kept every single thing from the day he got it brand new, I got very lucky on this buy he had every single receipt for everything that was done to it.

I went through all the manuals and cannot locate that green thing anywhere lol, so either the mechanic is right or wrong

I hope you guys have some idea

The reason why I cannot take it to him is because I don?t want to run the boat in this condition and I don?t want to get it towed until I am certain that I cannot do this myself as the last resort

Thanks again guys

 

[Bondo]

Re: 1993 Mercruiser 7.4L Bravo 454 High Temp - Overheating - Sea Ray Sundancer 1993

Wow thank you guys so much - that is very helpful. I also asked a Mechanic over the he could not spend too much time with me on the phone but here is something he wrote, after i sent him some pics

Alex,
Yes the raw water has been diverted thru the hull. So that green blue corroded thing is the strainer. The top can be removed to check flow and clean strainer. Check this first then check output pump. No output w good input equals bad impeller. Close strainer remove pump and bring over I will show you how to break down pump. Mp

Now, the crazy part is that the green corroded thing he is talking about has a hoses running through it like a T but those hoses are not connected to the sea pump at all they are leading someplace else and not even to the engine

Now of the sea pump hoses is leading towards a seacock with a huge yellow lever that’s set in upright position, this seacock is right next to the green blue corroded thing he was talking about

so I just want to make sure i am understanding him correctly why remove the strainer if the hoses are not connected to the sea pump just seems strange to me

by the way I do have all the manuals, the person who sold me the boat kept every single thing from the day he got it brand new, I got very lucky on this buy he had every single receipt for everything that was done to it.

I went through all the manuals and cannot locate that green thing anywhere lol, so either the mechanic is right or wrong

I hope you guys have some idea

The reason why I cannot take it to him is because I don’t want to run the boat in this condition and I don’t want to get it towed until I am certain that I cannot do this myself as the last resort

Thanks again guys

Ayuh,.... Donno why the strainer is by-passed,....

But,... If ya close that big yellow handled valve, ya should be closin' the seacock, 'n be safe from sinkin'....

Post some pictures if ya can...

 

[djalexg82]

Re: 1993 Mercruiser 7.4L Bravo 454 High Temp - Overheating - Sea Ray Sundancer 1993

Ayuh,.... Donno why the strainer is by-passed,....

But,... If ya close that big yellow handled valve, ya should be closin' the seacock, 'n be safe from sinkin'....

Post some pictures if ya can...

Thanks - see picks - the hose from the pump goes directly to that seacock which is on the left, middle seacock is head flush and to the rite is the green filter thing which he was talking abou

 

[djalexg82]

Re: 1993 Mercruiser 7.4L Bravo 454 High Temp - Overheating - Sea Ray Sundancer 1993

Also, does anyone know what kind of bolts are on the seapump?

thanks