Manifold removal and exhaust q's (1 Viewer)

[WGermer]

1977 fj40
2f no headers
Rebuilt carb 14 months ago

So I'm trying to track down a vacuum leak/exhaust leak etc. long story short, truck was running good, next day had to pull the choke to keep it running. Replaced engine fuse which helped a little (blown but couldn't see it with the naked eye). Replaced idle cut solenoid to rule that out. Testing with carb cleaner had small engine revs under the middle under the carb heat shield. Also sounded like at the base of the carb would slightly rev. The weird thing is what looked like smoke or exhaust that would come out from underneath the front and back of the manifold. And.... I could see exhaust seeping out between the coupled where the main exhaust pipe drops down.

My vacuum is around 12-13". Low right? I'm at 4000ft roughly.

So I decide to pull off the carb and manifold.

The rear bolt looked like a nightmare, but it was only on finger tight I swear. So I pull the whole thing out. Gasket doesn't look super bad. Looks to be some kind of metallic type.

Question 1 - is the front part of the manifold, supposed to be free turning? Does it need to be sealed better somehow? I'll try and post up a picture.

Question 2 - seems like when I put it back together with new manifold gasket, I could use the high temp gasket stuff along the block side. Does this sound alright?

Seems like I need to have the manifold side machined to a flat surface as well.

I also wanted to use the high temp liquid gasket to go I in-between the carb riser, and the carb, And in between the exhaust pipe that exits down.

Any other ideas or thoughts?

Thanks

Wyatt

 

[Bear]

The joints between the main body and the ends of the exhaust manifold each have two metal rings in them to allow rotation of the end pieces. There is a corrugated metal spring ring which is covered by a smooth circular metal ring in a groove cut into each end of the main exhaust manifold body. These are often destroyed or in pieces--a possible leak point.

Suggested is the Remflex brand manifold gasket with no other sealant used. Yes your surfaces should be flat and clean first. Using the thick Remflex gasket can help avoid expensive machining to precisely align the intake manifold with the exhaust manifold, if the two are first aligned on a flat surface and then bolted together before attaching the entire assembly to the engine.

You can read up here about this stuff. Good luck.

 

[shelfboy1]

usually all those bolts need is tightend they come loose and should be included in a maintenance schedule .if they leak for a while though they ruin the gasket and ya gotta replace it good luck

 

[WGermer]

Thanks for the feedback. Gonna order the gaskets for this.

Here's the after shot. I feel bad, I see other engine pics and they're so clean. Mine looks like its got leaks everywhere. It looks like I need the valve cover gasket. Can I put on the valve cover gasket, then take it off again to do the valve adjustment? or is it a one-time thing and when you take it off you replace it?


Thanks

Wyatt

 

[sggoat]

If the valve cover gasket is treated carefully., it should be able to be reused-maybe a couple of times,--It's not like you have as lot of splashing or oil pressurization going on under there.(more of a seeping/weeping type of oiling for the rocker)\

 

[Bear]

The Toyota valve cover gasket is "rubber" and should be okay to reuse if you don't mangle it. It is a one-piece affair and fits up inside a groove in the aluminum valve cover.

Sorry to say it, but you need to spend some time doing a good cleaning before reattaching anything. If you do have any type of leakage it will be much easier to notice it on a clean engine.

 

[WGermer]

Thanks guys. Yeah, this 40 was an impulse buy. I say impulse but I had watched for one for 3 years, but when I went and saw it, I just couldn't say no. I've owned it for 3 years now. Its got its fair share of rust, and the engine although stock and complete, is pretty neglected. I've been taking on little projects that I can handle as I go. This one is probably my biggest yet. I have to pick my battles carefully, because I don't want to end up with a torn apart 40, that ends up being too daunting of a project to put back together. I've seen way to many "projects" in various classified sections. I'd like to keep this one running and intact where I can.

 

[Bear]

Understood. But every time you take something off, degrease it, paint it if it needs done, and put it back on a clean spot. Eventually you get the whole thing done.

 

[65swb45]

Understood. But every time you take something off, degrease it, paint it if it needs done, and put it back on a clean spot. Eventually you get the whole thing done.

So true Michael. When I got into this thirty years ago, my family questioned how much time I was spending just pulling things apart to deal with 17 years of deferred maintenance. My answer was:" it's a machine, it has a finite number of parts. Eventually it will be done." After two years in purgatory, taking a ridiculous amount of tools with me wherever I went while I waited to see 'what happens next,' i finally returned Ruftoys to the state of reliability Mr. Toyota intended.

 

[Bear]

Phew. When I just saw you "quoted me" I thought: now what did I say incorrectly.

I too am realizing that completely taking these trucks apart to do a good job, while admirable, leaves you without the fun of actually using them over the long haul of restoring them. It's just that I hate greasy, filthy machinery even if it's a part that's just lying around.

So thanks Mark for not chewing me out.

 

[WGermer]

All good advice.

So on the rotating ends of the exhaust sections, do those pull out to change out the seals inside?

Here's a video of what looks like exhaust leak before I started pulling apart the manifold. I can only guess that it was coming from either end where the sections can twist. This was right after startup, so I think thats why the exhaust is so visible, later on when it gets more warmed up the exhaust isn't so "white".

https://www.dropbox.com/s/61lcocdakr1f47c/exhaust leak.MOV?dl=0

It seemed like manifold was snugged up really well (except the rear bolt that was not that tight).

I'm soaking the bolts holding the exhaust and intake together. then i'll pull them apart.

 

[roma042987]

redo them both and be done with it. here is what I did on a 75 and on my 87 fj60
https://forum.ih8mud.com/threads/tucker-and-romas-75-fj40-restore.729307/page-6

 

[WGermer]

Wow roma, your 40 looks amazing. Nice work. Thanks for the link.

 

[roma042987]

Wow roma, your 40 looks amazing. Nice work. Thanks for the link.

thanks! that 40 technically isn't mine. I sold it to the gent and then he asked me to spiff it up hence the build thread. my 40 is in my signature. I hope those pictures helped to see how the exhaust horns work and if your pulling it apart what to expect. On my 87 fj60 the bolts that bolt the intake to the exhaust manifold broke so I drilled them out installed a timesert and loctited some long studs into the exhaust manifold and then lowered the intake onto the studs and secured with nuts.

 

[WGermer]

So I've got a few more questions. Here's my progress so far.

I got the intake separated from the exhaust, but one of the short bolts sheared off. I tried cutting a slot in the protruding stud, and turn it out, but it wouldn't budge. I then drilled it out, going from a small drill bit to larger. I started to tap it, and finally got the tap in and out, but the threads just don't look that great. In fact they look bad to me. On the side where the bolt came out, I re-tapped it to clean it out, but even that didn't feel great. And it almost looks worse than the other.

Am I too worried about this? or should I just run the tap through both of them again and hope the new bolts hold? Or do I need to try and tap a bigger size? This is the m10 x 1.25 now.

1st pic is the bolts as they came out. You can see the threads look kind of mangled as they came out.

2nd pic is the hole the short bolt came out of. Re-tapped, but threads look weak.

3rd pic is the hole I drilled out, and tapped. Again. thread quality?

 

[antFJ]

does the bolt tighten? i think then you will have your answer

 

[WGermer]

does the bolt tighten? i think then you will have your answer

I think new bolts would hold... but to what torque? Gotta think on that.

 

[antFJ]

all i'm saying is test the desired torque.. if it fails then you have your answer... only option then is to source a new one or helicoil/timesert

 

[WGermer]

all i'm saying is test the desired torque.. if it fails then you have your answer... only option then is to source a new one or helicoil/timesert

Got it. Thanks antFJ.

 

[WGermer]

I've ordered new seals, but I'm unsure on what to do on the exhaust horns. The right side horn will not budge. I can't get it to twist, or come out. Its like its cemented in. The left side horn twisted easily and came off no problem. I've seen the prices on the rings, and they're pricey! It looks like you need 2 rings and 1 spring per side. Does the spring sit behind the horn as you slide it in? How do the rings help seal it? Are they supposed to expand outward to fill the gap? I'm attaching a picture of my left horn that came out.

Any ideas on what to do on the horn that won't come out? I've tried hitting it with a rubber mallet, and even some gentler hits with a hammer.

Any help is appreciated.

thanks