SAAC Forum

The Cars => 1967 Shelby GT350/500 => Topic started by: B Devlin on February 23, 2022, 03:21:24 PM

Title: GT 500 Water Pump Sealing
Post by: B Devlin on February 23, 2022, 03:21:24 PM
Hi all,

Is there a preferred sealant for the lower passenger side water pump bolt?

Related, would it be smart to clean those threads with a die to possibly make a better seal?

For the gaskets, I'm guessing any brand name silicon sealant will work. Ture?

I know these are basic questions, but it's been about 30 years since I've installed a water pump. I'm definitely willing to ask for help.

Thanks,
Bill
Title: Re: GT 500 Water Pump Sealing
Post by: Royce Peterson on February 23, 2022, 04:12:39 PM
I use Permatex #2 on the bolt you are talking about.
Title: Re: GT 500 Water Pump Sealing
Post by: Bob Gaines on February 23, 2022, 04:22:20 PM
Quote from: B Devlin on February 23, 2022, 03:21:24 PM
Hi all,

Is there a preferred sealant for the lower passenger side water pump bolt?

Related, would it be smart to clean those threads with a die to possibly make a better seal?

For the gaskets, I'm guessing any brand name silicon sealant will work. Ture?

I know these are basic questions, but it's been about 30 years since I've installed a water pump. I'm definitely willing to ask for help.

Thanks,
Bill
Bill ,I am not sure if it is relevant to your situation but when using a silicone sealant be sure to wipe off excess that squeeze's out the sides for the best looking job. Also engine paint does not adhere well to silicone if there is excess and you are wanting to touch up.
Title: Re: GT 500 Water Pump Sealing
Post by: vtgt500 on February 23, 2022, 06:09:54 PM
Yes!  I exclusively us Loctite PST for threaded, fluid fittings.  Is a non hardening, PTFE paste.  Works flawless for such applications.  Critical to remove all contaminates form taped holes.
Also, retap threads with a precision, ground thread machinist thread tap.   Never, never use unground hardware store thread taps.
It maybe sacrilegious but I gave up building collector car engines with vintage fasteners.  I exclusively use ARP stainless steel threaded fasteners.  Purchase lengths to yield maximum thread engagement for hole depth.  We have all stared in horror of a broken water pump bolt or seized, FE exhaust manifold bolt.  Never again.
Title: Re: GT 500 Water Pump Sealing
Post by: B Devlin on February 23, 2022, 06:30:33 PM
Thanks, guys. This is too much work to have a leak that can be avoided. To Mr. Gaines, yes, I'll want to do a touch up so thanks for the reminder WRT excess silicone sealant. Not having leaks is important, but looking good also counts.

Bill
Title: Re: GT 500 Water Pump Sealing
Post by: JWH on February 23, 2022, 07:30:39 PM
Hi Bill, Permatex makes a specific sealant for Thermostats and Water Pumps that I have used with very good results over the years. It is available at most any auto parts store. This is to seal the gasket and it is different from the Thread Sealer previously recommended.

https://permatex.com/products/gasketing/speciality-gasket-makers/permatex-water-pump-thermostat-rtv-silicone-gasket-maker-5-oz/

As a side note, I like to take a small amount of liquid dishwashing soap and smear a thin coat inside the ends of the radiator hoses when installing. This helps slide them on easily. The dishwashing soap dries leaving a good seal when the hose is in place. This has worked well on heater hoses also. It also makes it very easy to remove the hoses right away when you realize your forgot to install the band clamps before sliding the hoses in place (ask me how I know). 

Title: Re: GT 500 Water Pump Sealing
Post by: B Devlin on February 24, 2022, 12:40:38 PM
Thanks, JWH. I've used liquid dish soap in the past and it does work well. That Permatex makes a sealant specifically for thermostat housings and water pumps is new to me (and maybe others).

Bill
Title: Re: GT 500 Water Pump Sealing
Post by: tonys_shelby on February 24, 2022, 03:24:39 PM
+1 on Permatex thermostat and water pump sealant