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RTV Question

Hossbaby50

Hossbaby50

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I need to replace my water pump this weekend. What color RTV should I use on it? I have copper, blue, and black. I used black on my thermostat, and it leaked. So I went to copper and it has held sofar. Should I use the copper or is there a specific color I should use. thanks

Harley
 
Gaskets are usually better. I just install them after I clean the block up real nice at the mating surfaces.

But I'll second blue or copper RTV.

John /forums/images/graemlins/usaflag.gif
 
It does have the gaskets. If I don't have to run RTV, thats even better though. Then I don't have to wait for it to dry.
 
Yeah, if you've got the gaskets, just clean up the two surfaces good (scrape off junk with scraper, maybe light sanding too) and then just use the gaskets by themselves. Only tricky part is getting the waterpump mounted without the gaskets falling through to the ground a couple times. /forums/images/graemlins/smirk.gif
 
This is a serious question...you don't use RTV with gaskets? I just bought both...haven't done anything yet...but it would be nice to know for sure.
 
[ QUOTE ]
Only tricky part is getting the waterpump mounted without the gaskets falling through to the ground a couple times. /forums/images/graemlins/smirk.gif

[/ QUOTE ]

Use a short length of sewing string, or some real light fishing line. It will allow the bolt to go through but hold the gaskets on until you can get the bolt started. Then, as soon as its started, just break the string and you're good to go.

John /forums/images/graemlins/usaflag.gif
 
[ QUOTE ]
NEVER USE BLUE RTV

[/ QUOTE ]

Ok I'll bite, why? /forums/images/graemlins/confused.gif /forums/images/graemlins/smile.gif

I usually use copper, but what's the difference?

Thanks,
John /forums/images/graemlins/usaflag.gif
 
Nope, I don't use RTV on the gaskets if I've got 'em. Some people do, but not me. That's what gaskets are for; if you had to smear each one up with RTV before installing it (on both sides) think of all the extra work and money a factory would need in putting and engine together. It just doesn't happen.
(Go ahead "gasket experts" flame on /forums/images/graemlins/smirk.gif)
 
As far as RTV goes, all I ever use is the black stuff. I use it whenever I use RTV, like on diff covers. As far as using it with a gasket, I wouldn't. Use one or the other, just not both.
/forums/images/graemlins/burb.gif /forums/images/graemlins/thumb.gif
 
Blue and clear RTV are a real slick compound. They allow oil and coolant to pass right by. The only time I have ever seen blue seal was on a front axle, and thats because gear oil is real thick when its not hot. Black, grey, or copper are the best to use when putting things together. I use copper on water pump gaskets, and on edges of valve cover gaskets(keeps them from slipping when istalling). I normally use black or grey for oil pan gaskets when they are multi poece gaskets. As for intakes, the grey works awsome to seal the front and back. Grey is intended to do things like that. Most newer chyslers and imprts dont use oil pan gaskets, and they recomend the grey silicone. Its the only one that doesnt leak.

Dan
 
The trick to getting stuff to not leak with RTV is you have to apply a real thin, even coat all the way around. It is best to do so around places with thin gaskets, like timing chain covers. The RTV will fill in any imperfections in the cover or the block. I always smear the RTV with my fingers to get an even coat. It is messy though.

Dan
 
[ QUOTE ]
Only tricky part is getting the waterpump mounted without the gaskets falling through to the ground a couple times.

[/ QUOTE ]
The trick lies in that rattle can of red spratack, that [censored] hold gaskets in place like a charm.
I would personally go with Fel-Pro w/p gaskets, but the replacement ones are ok too. I'd definately use the Blue gasket snot. Nothing else is quite as good for water related uses.

/forums/images/graemlins/usaflag.gif
 
Silicones are all similar with the main difference being the temp range. Blue, black, red, then copper as far as temp resistance from lowest to highest ratings. I now use the copper on everything..... stay away from the generic stuff & buy Permatex brand. I have found this to be the best stuff going. Silicone is good for sealing thick gaps... Oil pan, valve covers, intake manifold rails etc. Most silicone is not good around gasoline. Silicone will also make gaskets slide out of place (I've seen waterpump gaskets blow out from using silicone on them) The best advice said above was to use "high tack" or gasket shellac on the water pump gaskets. Coat, install on block, let dry & install the pump without fear of them sliding out of place.
 
I gave up using RTV on gaskets (unless at mounting surfaces between gaskets like the intake... this is an "as instructed" application).

My conclusion is that it makes the gaskets slip out of place easy (especially on the old 4 bolt SBC valve covers) and with any amount of uneven application it doesnt seal well (one area up leaves a loose area).

All gaskets using RTV only for the joints and coating bolts threads (especially water pump bolts). Be careful about use on bolts in torque sensitive areas (especially newer intake gaskets)... it can mess up your reading.

And to answer the question, I use black. Machinest scolded me on blue and, after using black, I'll never go back. Seems to have a longer shelf life and a better seal.
 
the only time i usually don't use RTV is if the paper with the gasket says not to use it or if it says to use something else or on rubber gaskets. when i do use it i use black,and never had any problems. i used it on my water pump 2 years ago and it's still holding strong. /forums/images/graemlins/thumb.gif
 
I will use RTV, or the gaskets...
NEVER will I use both, that's just asking for a problem.
If gaskets didn't work so well, engines would have been assembled with RTV to start.....

/forums/images/graemlins/usaflag.gif
 
Thanks for the explanation. Now I feel like I need to go back and replace the blue stuff I've used in the past.

I didn't buy the cheap blue stuff, the blue I bought was actually more expensive then the copper stuff. And its a light blue color, not the typical blue.. I dont know if it will hold or not, but I do know one thing, I will never use blue again.

Thanks,
John /forums/images/graemlins/usaflag.gif
 
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