Silicone Gasket On Carb??

4lowNgo

 
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Three months ago I had a brand new carburetor installed on my FJ60. Since then, the manifold has warped and I'm in the process of having a new one installed.

When they removed the carb to access the mainfold, they discovered that the shop that installed the carb used silicone to create the "gasket"s for the carb. They have since fabbed gaskets with gasket material (is this O.K.?)

It's really frustrating trying to find a reputable, competent shop. The one that did the carb had my confidence, until they screwed up bigtime last year on another manifold issue, and the truck really never has run right. They're the ones that recommended replacing the carburetor. I had a two+ year relationship with them and felt like they had it together.
This new shop gives me the same impression...the are the Lotus, Rolls, Jag, Porche, Mercedes, etc. experts and are doing a detailed, conscientious install with this manifold..... but we'll see.

I don't have the knowledge, tools or buddy backup to tackle stuff like this myself, or I would.

Anyway, slight rant there.... but what about that silicone-for-gasket trick???
 

FJ40Jim

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Here comes the RANT.

NO. no , no!
Silicon RTV is not acceptable for fuel contact. It turns into gelatinous snot and eventually gets sucked into the engine. RTFM and RTF package :frown:

Furthermore, there is NO separate carb base gasket on 2F engines. The plastic insulator block has a very nice gasket permanently bonded to the top & bottom of the block. The block can be reused many times over without hurting the gasket material. If somebody has F*%^ed up the insulator block gasket, the proper fix is a new insulator block. They can be obtained overnight from any toyota dealer.

I see this sh1t everyday and it really gets me that other so-called "professionals" are often the culprit. :mad:

Rant off. Y'all can go home, there's nothing to see here...
 

Landpimp

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new insulator is about $80-90 from the dealer, I replaced mine.........well just because I was replacing everything else ;)
 

4lowNgo

 
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From what I was told, the insulator block was fine. I was told there was another gasket, that's what they fabbed. I'll check again when I pick it up today.

P.S. What is RTV, RTF, RTFM??
 

FJ40Jim

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RTV= Room Temperature Vulcanizing. A type of liquid rubber that will chemically vulcanize itself when exposed to atmosphere. AKA silicone gasket sealer.
RTFM= Read the freakin manual.
RTF package= Read the freakin package.
 
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There was no other gasket. FJ40Jim is the man, you should have sent your old carb to him for a rebuild instead of buying a new one.

No Gasket besides the one on the insulator block.....

You would probably be best served by buying some tools and the FSM. What you learn will turn out to be priceless.
 

4lowNgo

 
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I plan on getting the FSM very soon. I know I need to just dive in and try it. I think the gaskets they were replacing are the ones that Kevin references above.

They can't hurt, can they??

FJ40Jim: what do you charge to rebuild a carb? (I have two extras) PM Me.
 

GLTHFJ60

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Is the insulator block mounted between the carb and the intake manifold? It is also called a heat shroud, right?

:beer:
 
Last edited:

Landpimp

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AFAIK, replacing the carb would have had no effect on the warped manifold(s) so I would blame the shop for that.

You can plane the manifold or get a new set from Toyota, $500-600, me i bought a new pair, to me it was worth it.

John

4lowNgo said:
Three months ago I had a brand new carburetor installed on my FJ60. Since then, the manifold has warped and I'm in the process of having a new one installed.

When they removed the carb to access the mainfold, they discovered that the shop that installed the carb used silicone to create the "gasket"s for the carb. They have since fabbed gaskets with gasket material (is this O.K.?)

It's really frustrating trying to find a reputable, competent shop. The one that did the carb had my confidence, until they screwed up bigtime last year on another manifold issue, and the truck really never has run right. They're the ones that recommended replacing the carburetor. I had a two+ year relationship with them and felt like they had it together.
This new shop gives me the same impression...the are the Lotus, Rolls, Jag, Porche, Mercedes, etc. experts and are doing a detailed, conscientious install with this manifold..... but we'll see.

I don't have the knowledge, tools or buddy backup to tackle stuff like this myself, or I would.

Anyway, slight rant there.... but what about that silicone-for-gasket trick???
 

chitown40

 
 
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cruzerfetish said:
There was no other gasket. FJ40Jim is the man, you should have sent your old carb to him for a rebuild instead of buying a new one.

No Gasket besides the one on the insulator block.....

You would probably be best served by buying some tools and the FSM. What you learn will turn out to be priceless.
Not to discredit anyone here, but according to SOR there is a carb base gasket as well as a carb plenum gasket. See below link, scroll down to 1/75-8/87 pics. #90 and #91.

http://www.sor.com/sor/cat042.tam?xax=11611&page.ctx=cat042.tam

I also purchased a 'head rebuild' gasket set from SOR came with a base gasket for the carb. I believe it goes on top of the insulator between the carb.
 

FJ40Jim

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There is no gasket available from toyota and none shown in the FSM or fiche. There is a gasket pictured in the SOR photo. That is not a genuine Toyota gasket and should not be used. The only gasket that belongs there is the one that is bonded to the heat insulator. There are carb base gaskets packed in some aftermarket engine gasket kits and aftermarket carb rebuild kits. They should be discarded and the proper reapair done.
 

FJ40Jim

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OKay, I just looked at the SOR photo. As you can hopefully (if the pic uploaded OK) see there is a light colored gasket bonded to the insulator in the photo. There are some loose gaskets (dark colored) shown there also, but they don't belong because as can plainly be seen, there is already a gasket bonded to the block.
042-01H.jpeg
 

FJ40Jim

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4lowNgo said:
I plan on getting the FSM very soon. I know I need to just dive in and try it. I think the gaskets they were replacing are the ones that Kevin references above.

They can't hurt, can they??
Yes, they can hurt. These engines are known to be sensitive to and prone to manifold vacuum leaks. Piling on more gaskets does not create a better seal. It merely creates more opportunity for failure.

"Friends don't let friends stack gaskets!"
 

65swb45

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Jim and I agree about a great many things when it comes to carbs, and to LCs in general, but I would not be so hard line on the gasket situation. I would ABSOLUTELY agree with him about staying away from the silicone and RTV.

I evaluate each situation on its individual merits. If I clean up a customer's intake manifold, lay their insulator on it and it feels wobbly, I'll go grab a fresh insulator off the shelf and try it. If it still feels wobbly, then I'll call the customer to tell them they've prolly got a manifold issue.

They'll usually ask what I recommend and I suggest pulling the carb studs to check the deck with a straight edge and find out how bad it is. If it doesn't seem too bad, I'll recommend trying ONE insulator gasket as a cheaper alternative to the expense of pulling the manifold.

The insulator gaskets I offer do not come as part of any kit I sell: I purchase them separately just for this type of use. They are not made of the same material as the ones bonded to the factory insulator, or of the material SOR uses for their gaskets. These gaskets have a little more 'give' to them which really helps in this situation.

That said, I will also admit there have been times where I have installed the gasket and it has not 'felt' right [I can't explain what that means, I just know when it happens] and I will pull the gasket back out and take it back off of the customer's bill. So I am not 100% sold on them. I just like having them as an option.
 
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Hmmm, interesting information here. The intent of a gasket is to fill voids in machined faces that may not be flat or parallel to the mating surface. I am in complete agreement with regards to RTV usage, major no-no. However, a person might employ the same tactic used on certain gaskets, two coats of KopperKote. This is done many times on motorcycles which are air cooled and subject to uneven expansion/contraction through the steel studs tying everything together. Of course there is no liquid gasoline present so I'm not sure this is a good issue or if there is a breakdown issue involved with the KopperKote. For gasket making there are many better alternatives than RTV.
 

65swb45

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Hmmm, interesting information here. The intent of a gasket is to fill voids in machined faces that may not be flat or parallel to the mating surface. I am in complete agreement with regards to RTV usage, major no-no. However, a person might employ the same tactic used on certain gaskets, two coats of KopperKote. This is done many times on motorcycles which are air cooled and subject to uneven expansion/contraction through the steel studs tying everything together. Of course there is no liquid gasoline present so I'm not sure this is a good issue or if there is a breakdown issue involved with the KopperKote. For gasket making there are many better alternatives than RTV.
It must be karma that YOU chose to revive THIS old thread Lenny. I took the carb apart today that you had sent to me. The carb was definitely rebuilt...at some point, but run, and run poorly after that. The air horn is quite warped and, guess what, the shop installed TWO GASKETS between the air horn and the fuel bowl to try and deal with the warpage. The dirt you saw in the pics was evidence the dual gasket setup did not work.:rolleyes:

I will try and snap a 'before' picture tomorrow...BEFORE I straighten the air horn.;)
 
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what is a good sealant i can use for the carb insulator so that it wont seize up when i have to take it apart again later?
 
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