Gaskets or RTV or Both.. What Do You Use??

[Lakeroadster]

I've always used gaskets and RTV. My old '27 roadster keeps spitting out water pump gaskets and some fellas are saying I should not even use a gasket, just use RTV?

The engine is a 5.0 HO Ford.. I know it's off topic, but I am a Chevy guy with a Ford motor in one of my hot rods and I am looking for some advice from ya'll. I've considered a SBC swap, but that seems drastic when the only issue is a water pump gasket.

The gasket that keeps failing is the one that is between the sheet metal backing plate and the water pump housing. Here is a photo, you can see the pesky gasket failure at the bottom of the photo.

 

[ccharr]

By chance have you tried a different water pump? Reason I say that is on the 01 Roush I had they changed two different water pumps before they were able to stop the little leak it had. Just a thought.

 

[vwnate1]

Gasketing

Maybe get some Gaska-Chinch shellac and coat both sides of the paper gasket and allow to tack up a bit before installing ? .

I use this excellent product on a regular basis on fuel pumps etc. that don't suffer much heat .

 

[Lakeroadster]

Thanks for the advice fellas.

I reassembled the Water Pump to the Engine yesterday.

I modified a Fel-Pro 35380 Pump to Cover Plate Gasket to give a bit more width in hopes that will help prevent another gasket failure. I also made some stainless studs to plug the two tapped holes that are not used in the timing cover.

Pump to Pump Rear Cover Plate Gaskets: P/N 35214 shown on left, P/N 35380 on the right:


This photo shows the P/N 35214 on top of the modified P/N 35380. Notice this results in a little wider gasket in the area that has failed twice on my '83 5.0 Motor:


The stainless studs I made to go into the two tapped holes:


The location of the unused tapped holes. I coated the studs with RTV and installed them into these holes.:


I used Permatex #765-3017 Water Pump Housing RTV on the gaskets and the stainless stud plugs. This grade of Permatex is stated to have Superior Water-Glycol Resistance.



And lastly I modified a 1/2" combination wrench to allow snugging up those two lower back cover bolts.



Getting the wrench into location is tricky, but it works.


Wish me luck fellas...

 

[vwnate1]

Looking Good !

I'm not clear as to why you couldn't tighten those rear bolts before mounting the water pump.....

I sure hope you wire brushed the inner sealing surface shown in pic # 3 ~ .

That cavity looks like it was full of rusty water a while before you began working on this rig .

I assume a Customer's rig ? .

 

[Lakeroadster]

I'm not clear as to why you couldn't tighten those rear bolts before mounting the water pump.....

The Permatex Water Pump RTV states to assembly while RTV is still wet and hand tighten, then tighten with a wrench after an hour. Thus the bolts have to be tightened before assembly and after assembly.
​

I sure hope you wire brushed the inner sealing surface shown in pic # 3 ~ .

All steel mating surfaces were wire brushed, all aluminum mating surfaces were hand scotchbrite cleaned, then all surfaces were wiped down with acetone.​

That cavity looks like it was full of rusty water a while before you began working on this rig .

On a 5.0 Ford that cavity only sees antifreeze when a gasket lets loose. It even has a little slot cut in the bottom to let the water drain out. Not sure why that was so rusty?​

I assume a Customer's rig ? .

Not a customer's rig, it's my '27 Ford Roadster that I built about a decade ago..​