RTV Sealant ?

[TboneMan]

Stupid question:



I've read the threads on changing the fluid on my 6 speed (NV5600) and they mention RTV sealant.



Is this like a liquid gasket or something?



Do I just go into an NAPA and ask for RTV sealant?

 

[illflem]

It's a common auto parts item in your choice of colors and regular or high temp.

RTV= Room Temperature Vulcanizing

I use Permatex Anaerobic Flange Sealant

 

[TboneMan]

I assume that I would want high temperature for the PTO cover.

 

[Ncostello]

Ever used bathroom caulk or silicon caulking? Its about like that. For transmission and diff seals I like the Permatex Brand Ultra Grey RTV. Recently I also started using the Cummins Triple Bond Grey. Its about double the cost if not more but I really like its characteristics and workability.



The key with this stuff is knowing how much to use. Too little and it leaks. Too much and it makes a mess and can ooze off the parts and get into the internal parts.



Take a differential cover for example. The sealing surface is about 3/4" wide... . what a gasket would normally look like. But a 1/8" wide "bead" in the middle of this surface all the way around would flatten out and cover the whole surface. Make sure you apply the bead all the way around holes too. Once covers etc are tightened down, the gap left between the parts is filled with the RTV stuff and it cures to form a nice seal. But that gap is very thin which is why too much is not a good thing. It just gets squeezed out and goes somewhere else. Good Luck.



I used to hate this stuff but I'm getting more used to it over the years of using it.

 

[BV]

RTV Sealant

Pick the right one for the job from the Permatex web site.

 

[jmtandem]

RTV number 3

Ncostello,



Do you think RTV number 2 (the black stuff) can be safely used on the threads of the fuel pressure gauge sending unit where the hose attaches to the sending unit? (Not where the sending unit hose attaches to the test port. ) I am not a fan of teflon tape and wonder if the tape is compatable with diesel fuel. I have a little weeping at the connection between the hose and the sending unit. (I am as tight as I dare go on the connection, it is not loose. ) The TDR magazine that described the fuel pressure gauge installation procedure talks about using teflon tape starting two threads down. I would hate for any of the tape to get into the line and have to be trapped by the fuel filter; maybe that is impossible, I am just concerned. Any ideas?

 

[DavidC]

I used #2 on my fuel pressure sending unit snugged it down and no leaks. Stay away from tape if at all possible, it has it's place and this is not one of them.



Dave

 

[JohnE]

thread sealant

Use Loctite PST or ... . I cannot remember the Permatex equivalent. Both products are a white paste containing teflon and other sealants, work very well to seal and don't have the leavings of tape. The only trick is to drive it deep into the threads to make sure you get it buttered into the mating area.



I'm with illbay.

Anerobics are great products. I do strongly recommend using accelerators with them for home use. Most anerobics are designed for OEMS where you usually have several days between building the assembly and filling it with lube on the final line. It usually takes at least an hour of cure (at ideal temperatures) to cure an anerobic enough for fill.

 

[Ncostello]

The permatex thread sealant (white stuff) is good and can be purchased in small tubes. I use it on air brake fittings too. Works great there. Works great on fuel fittings. Just dont goop it on. Treat any work involving fuel fittings with great caution and perfection. Dont slop anything into the fitting ends... just keep it on the threads... I like using a small painters brush for that.



I've heard others use never-seize on fuel fittings. Claims it works good too.



I love that orange stuff that OEM's put on threaded fittings. Dries kinda hard but still flexible. I just don't know what it is. Usually find it on air brake parts (valves) where the fittings are pre-installed. Anyone know what it is?

 

[RustyJC]

Originally posted by Ncostello

I love that orange stuff that OEM's put on threaded fittings. Dries kinda hard but still flexible. I just don't know what it is. Usually find it on air brake parts (valves) where the fittings are pre-installed. Anyone know what it is?

Probably something like this:



Loctite 569 Thread Sealant



Rusty

 

[JohnE]

<blockquote>...

I love that orange stuff that OEM's put on threaded fittings. Dries kinda hard but still flexible. I just don't know what it is. Usually find it on air brake parts (valves) where the fittings are pre-installed. Anyone know what it is?</blockquote>

You're referring to Vibra-Seal. It is a Loctite product. It is OK if the OEMs apply enough. The great thing is that PST can be applied over the top.