HELP!!! Blown gasket question from long time lurker first time owner

Joined
Sep 6, 2017
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76
Location
Connecticut
Hi guys,

First time posting, happy to be part of the hang now as I just purchased a 1973 FJ40.
My girlfriend and I are about to start a 2,000 mile roadtrip and we just found there was an air leak coming from the manifold gasket.
We are supposed to leave in a few hours because of our schedule and our mechanic is giving us 3 options to install the new OEM gasket.
1- Use Permatex red or gold High Rate Silicon , problem is it'll take 24 hours to cure and we don't have the time.
2 Use Aviation gasket fluid that will apparently cure in no time, but he's not 100% sure it'll last for our roadtrip
3 Use no gasket fluid/silicon as Toyota recommends.

We are able to get to a shop after 1 week (2,000 miles) and do this right but we need to know what our best option is at this moment.

Any suggestions or input would be greatly appreciated.

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Joined
Dec 19, 2015
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We used to use gold sealant when I worked in a dealership, we only used to wait 3 hours. We used to use it to seal sumps mostly or gearbox. Not sure if it is the same type, but remember that by the time you have torqued the manifold up, the layer of sealant is very thin so the drying time wouldn't be as long as if applied thick. If you have a gasket then I would never apply sealant to it as the gasket alone should do its job.
 

BMThiker

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You posted in the FJC forum...moving to the 40-55 forum.
 
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On Mud you'll get several recommendation on what gasket to use. I frankly don't care what gasket you use, but I do care how you apply that gasket:
1. Do not use a silicone based adhesive, it melts then runs out like water once it gets hot.
2. Use Coppercoat, it is a lacquer based adhesive that bakes-on when it gets hot, then would hold fairly well even if the mounting nuts loosen.
3. Do not use "spray-on" coppercoat, it has been watered down to get out the spray nozzle. Use paint-on coppercoat, paint all four surfaces
(head, header, both sides of the gasket).
4. Don't hesitate over-tightening the mounting nuts (well beyond Toyota spec).

Then when doing #1 through #4 above, you can drive immediately and let the manifolds start baking-on immediately.
 
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4. Don't hesitate over-tightening the mounting nuts (well beyond Toyota spec).

Amen - and I used threadlocker on mine, after they kept coming loose!
 
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FYI, for headers you may need 1/2 washers to shim the headers to be the same thickness as the intake. It does vary depending on the header manufacturer.

P.S. don't sheer off any studs while you're torquing beyond 'specs'
 
Joined
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I can't answer to the thickness of other Headers, but when Downey built Headers our flange thickness was so close to the stock intake manifold thickness that merely over-tightening the nuts sealed very well without use of 1/2 washers- - -but that was back in the day using a thick asbestos gasket that compressed real well. Toyota mounting nuts are suppose to be softer metal than the studs (intentionally) so that you would strip a nut before you would snap a stud in the head- - -but sure as heck if I told you that you would snap off a stud ???
 

Mace

rock scientist..
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Mic the mounting surfaces and see how much different they are.

then start making decisions..
 
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Awesome, advice from an experienced knowledgeable person above move.


Now where's the thread of you documenting your adventure with your 40 series
 
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