Engine component reassembly - water pump, crossover, heat exchanger

[R-and-R]

Hello all,

Today I embarked on the project to replace the coolant circulating pump on my 8.1L mercruiser (port side). It's in a 2002 340 Sundancer.

Of course, to remove the pump, I had to remove the coolant crossover and the heat exchanger. Now that I have easy access, I'm thinking I might as well replace hoses too.

I'm wondering what your thoughts are on various goop uses for reassembly.
Bolts - thread locker? anti-seize? nothing?
Hoses - silicone? nothing?
Gaskets - sealant (type)? nothing?
New temp sensors (teflon tape?) while I'm here?

Any advice greatly appreciated.

Rob

 

[Bt Doctur]

Being this is for a circ pump assembly
Depending on the application of the bolt , never-seize, PermaTex Aviation sealant, grease
hoses usually get installed dry
gaskets , PermaTex Aviation sealant
PermaTex Aviation , can`t use any type of tape sealant because the threads need to make contact for the senders/sensors

 

[LG111]

Hello all,

Today I embarked on the project to replace the coolant circulating pump on my 8.1L mercruiser (port side). It's in a 2002 340 Sundancer.

Of course, to remove the pum7p, I had to remove the coolant crossover and the heat exchanger. Now that I have easy access, I'm thinking I might as well replace hoses too.

I'm wondering what your thoughts are on various goop uses for reassembly.
Bolts - thread locker? anti-seize? nothing?
Hoses - silicone? nothing?
Gaskets - sealant (type)? nothing?
New temp sensors (teflon tape?) while I'm here?

Any advice greatly appreciated.

Rob

What went wrong with the coolant pump?

 

[R-and-R]

Being this is for a circ pump assembly
Depending on the application of the bolt , never-seize, PermaTex Aviation sealant, grease
hoses usually get installed dry
gaskets , PermaTex Aviation sealant
PermaTex Aviation , can`t use any type of tape sealant because the threads need to make contact for the senders/sensors

Thanks Bt. The main bolts that I'm concerned about are the crossover-to-head bolts and the pump-to-block bolts. I'm thinking maybe some never seize on the threads, and try to make a collar of sealant around the shank at the head of the bolts.
For hoses, I'd seen some guys talk about silicone to make installation and future remove easier, but still not sure about that one.
No tape on the sensors makes sense.

Thank you!

 

[R-and-R]

What went wrong with the coolant pump?

See the pics attached.
And the bearing was getting noisy.

 

[Lazy Daze]

Whatever never-seize you use, make sure it doesn't have metals in it (can cause corrosion). Hoses come off easily with the right tool (large cotter pin puller), but sure, you could put something on it. Aviation sealant is good stuff. Merc makes a product called Perfect Seal that is fantastic - you could use it on all of those areas. I recently used it at the beginning of last season on a large mooring shackle that stays in the water for the season (salt). At the end of season, the goop was still there and made removal way easier than normal.

 

[R-and-R]

Whatever never-seize you use, make sure it doesn't have metals in it (can cause corrosion). Hoses come off easily with the right tool (large cotter pin puller), but sure, you could put something on it. Aviation sealant is good stuff. Merc makes a product called Perfect Seal that is fantastic - you could use it on all of those areas. I recently used it at the beginning of last season on a large mooring shackle that stays in the water for the season (salt). At the end of season, the goop was still there and made removal way easier than normal.

Thanks for the tips!
Heading to Amazon to get Perfect Seal and non-metal anti-seize. I had some plain old Permatex Anti-sieze, but I looked up the description and it's loaded with metals.

I have some good tools for hose removal, but some of the hoses were seriously stuck to their fittings. To the point that removal caused some damage. This is a new-to-me boat and I'm doubtful that the PO has ever replaced any hoses, so I'm replacing them all now.

Thanks again!

Rob

 

[Lazy Daze]

You are welcome!

You may/may not find the Mercury/Mercruiser labelled Perfect Seal available outside of Merc dealers. But you can also get it under Merc's Quicksilver brand - same stuff, but labelled for sale outside of Merc dealers.

For your tools... if you haven't already, file the tips down a slight bit so they are more rounded. That should help - although sometimes it is what it is.

This is the one I have that I use 99% of the time - a little more reach, but same idea. I do have another that is somewhat similar to the one in your picture at the top - for those hose ends that are facing away from you, buried under the engine, like a fuel or oil cooler.

 

[LG111]

See the pics attached.
And the bearing was getting noisy.
View attachment 62786 View attachment 62787 View attachment 62788

Wow, that looks like it went to war! Good thing it's an easy fix. Save some $$$

 

[R-and-R]

Wow, that looks like it went to war! Good thing it's an easy fix. Save some $$$

I *suspect* that somewhere in history there was an exhaust hose leak resulting in saltwater spray around the port side of the ER. This pump is kinda buried below the heat exchanger and coolant crossover, so a less than thorough cleanup might've contributed to this. Cost of the pump plus several hoses, seals and sensors that I currently have access to will be about $500. I'd bet double or triple that if I handed it to a mechanic.

 

[JVM225]

Whatever never-seize you use, make sure it doesn't have metals in it (can cause corrosion). Hoses come off easily with the right tool (large cotter pin puller), but sure, you could put something on it. Aviation sealant is good stuff. Merc makes a product called Perfect Seal that is fantastic - you could use it on all of those areas. I recently used it at the beginning of last season on a large mooring shackle that stays in the water for the season (salt). At the end of season, the goop was still there and made removal way easier than normal.

I agree.
Perfect Seal is great stuff.

 

[Soulshine]

No need for anti seize compound when using Perfect Seal.

Merc P/S is a sealant and also acts as an anti seize compound on threads too.

Excellent stuff.

 

[Handsome Transom]

Thanks for the tips!
Heading to Amazon to get Perfect Seal and non-metal anti-seize. I had some plain old Permatex Anti-sieze, but I looked up the description and it's loaded with metals.

I have some good tools for hose removal, but some of the hoses were seriously stuck to their fittings. To the point that removal caused some damage. This is a new-to-me boat and I'm doubtful that the PO has ever replaced any hoses, so I'm replacing them all now.

Thanks again!

Rob

Wise to replace all the hoses you can while u have access and time