Water Pump/Timing Cover Plate Gaskets Dry or Wet?

[cjkeeliii]

OK, I know what the TM says, but I'm asking for real-world experience or opinions. I would like to go dry on both gaskets as it has worked well for the coolant crossover pipe and the rear coolant block-off plates. I'm using the Felpro gasket kit not the gaskets that came with the pump.

 

[scottladdy]

I recently replaced a water pump (January) and used the Fel-Pro gasket kit as well. For the timing cover plate to housing I went with the gasket dry. There is no real pressure and an oil/oil vapor environment. This is where GM specifies anaerobic sealant.

For the water pump to plate I used Permatex water pump and thermostat sealant on both sides of the water pump gasket. This is essentially a gray RTV. I did this because there was a little erosion on the plate and I wanted to ensure a solid seal. A 1/8" bead and all is well.

I plan on doing the exact same thing when I replace the pump on my other truck when it gets a tad warmer around here.

I hope this helps.

 

[timarr]

I used anaerobic sealant with gaskets, Purchased at advance auto. The stuff is not cheap but worth if it doesnt leak.

 

[MilChevyguy]

Great advice...my mechanic hasn't done the pump for my M1010 yet (free favor) as the weather warms I may have to do this my self.
Looked over the TM's....some Utube vids and it doesn't seem that hard.
I really like when members document and report as the go on the repair, if I end up doing this myself I will try to give back to SS for all the help so far.

BTW...is green coolant fine for the CUCV's? I assume there was no orange Dexcool back in the 80's?

 

[scottladdy]

Coolant Technologies

BTW...is green coolant fine for the CUCV's? I assume there was no orange Dexcool back in the 80's?

Standard ethylene glycol coolant should be fine. Any high quality product should work well for you.

Now that I answered the question, here is some additional information regarding the orange stuff.

In regards to Dex-Cool: You will see a lot of opinions regarding it's use. Some will say don't use it, others say it is fine.

My personal opinion and experience. Dex-Cool is one of the first large scale uses of OAT, Organic Acid Technology, coolant in the market. As any new technology is introduced there are likely to be issues, either real or perceived with the change of technologies.

Based on my research, the issues with Dex-Cool were two-fold.

1. The use of certain polymers in intake manifold gaskets which appeared to be attacked by a plasticizer used as a corrosion inhibitor. This appeared to be limited to a certain set of GM engines. Based on my research, it appears that the issue was more related to the engine design vs. the coolant itself.
2. Clogging of coolant passages. This was highly researched and was determined to be caused by poor cooling system maintenance. In addition, people would switch to Dex-Cool (or other OAT products) and would keep the "old school" open vented radiator caps originally designed for non-overflow open systems. You must use a cap that has a spring loaded valve for the coolant return to the radiator. If your valve dangles freely, change it if you want to use an OAT based product.

Dex-Cool and other OAT products (most extended life coolants) have been around for a very long time now. Improvements have been made. I have used Dex-Cool successfully for the past 14 years without issue. I use one other OAT based product, Honda AF/Coolant, in my Honda's only because I know the engineering behind that product and it is specified for these engines. I would use the Honda over the Dex-Cool in my trucks if it weren't for the fact that it is twice the price of Dex-Cool. While I feel I need a barrel full of coolant to fill up these Detroit Diesels, the Honda's have a relatively tiny cooling system capacity.

Why do I use it and the Honda Coolant? Three reasons:

• Extended life of the corrosion inhibitor "package". I change my coolant every 2 - 3 years regardless. The OAT provides a greater margin of protection "just in case".
• The OAT products do not contain silicates. These compounds can attack seal polymers used in newer engines. The OAT products are known to extend the life of things like water pump seals.
• Better management of electrolysis. Every cooling system is essentially a battery made up of dissimilar metals submersed in an electrolyte of sorts. The OAT products by design do a much better job of reducing the affects of this.

I recommend spending an hour or two researching the product choices on the internet before deciding.

So, if you choose to use the orange stuff, make sure you thoroughly flush your cooling system. I perform a final rinse with several gallons of distilled water before adding the coolant. I only mix with distilled water, never tap water. And, change your radiator pressure cap to a self sealing non-vented style. Caps are cheap. I replace mine with every coolant change, along with the thermostat.

This is my opinion and experience. Your mileage may vary

 

[Dave Kay]

OMG---- DON'T, I repeat, don't use Dexcool in your CUCV unless you've completely rebuild your engine and your doing a totally clean, first-time re-install with brand new radiator, hoses, water pump, thermostats, cap and ANYTHING even remotely involved with the cooling system. Because if Dexcool is just the least bit contaminated, or comes in contact with the green stuff or residue left over in your block, radiator, pump, whatever--- it will turn your cooling system into a muddy-orange, sludge-caked headache in less than a year. From personal experience I speak: Been there, done that! As Scottladdy advised--- do a search on use of Dexcool in older vehicles that previously used the green stuff, it's an eye-opener! Good luck!