Cleaning upper intake

[JustAnotherDave]

Hey all, I pulled the upper intake to check on the EGR valve intake and check vacuum lines (baselining a new truck, also failed emissions with high NoX a few weeks ago.) I'm not opposed to having it sit in a bucket of simple green overnight, but I wasnt sure if I should remove the last plastic component on the intake. I think it's called the vacuum filter? Anyway, I dont know how hard they are to get off. It looks like it has some kind of sealant at the threads. What do people normally do with this thing? I've looked around the forum a bunch but couldnt find any answers. Thanks!

Vacuum Filter

• JustAnotherDave
• Feb 8, 2018

 

[scottryana]

Just unbolt it. No reason to risk soaking it.

 

[inkpot]

It’s a 24 mm to unscrew it. I cleaned mine with carb cleaner. I put some Teflon tape on the threads and screwed it back in.

 

[JustAnotherDave]

Thanks for the advice!

 

[rolliges]

Popular little part these days....

 

[gummycarbs]

Anyone know the torque value? I couldn't find it in my PDF FSM.

 

[bigredmachine]

Anyone know the torque value? I couldn't find it in my PDF FSM.

when I pilled mine out it looked like a tapered thread so I just went till it was tight with a little tefelon tape on the threads, so far so good

 

[inkpot]

A little more than finger tight should work. It doesn't need to be very tight with a 24 mm wrench or you will mess it up.

 

[Malleus]

Anyone know the torque value? I couldn't find it in my PDF FSM.

I've looked for this part in every one of mine and it's not there. If someone finds it, please let me know. Most of the thread torque specifications for "X" to Air Intake Chamber are 13-14-lb·ft, FWIW.

Here's where I go when I don't know something:
Pipe Thread Installation Torque Table Chart | Engineers Edge | www.engineersedge.com
If you assume the Gas filter thread is about 1/4NPT, the torque value of 16-lb·ft is about right.

 

[inkpot]

I’m not gunna get out my thread pitch gauge and pull that rascal back off of the intake, but I thought the thread depth on that filter was less than that of standard pipe. With a little Teflon tape on it, it won’t take much torque to seal it and secure it from backing out. No rocket science required?

 

[Malleus]

For sure. It can't be standard pipe, because the Japanese don't use it. I don't have a reference for Japanese metric, parallel or tapered pipe threads (I gave up long ago when trying to plug my 40's smog manifold), so I posted this as a rule of thumb reference. Unlike most things on this truck, I don't think the torque here (beyond tight) matters much. Tapered threads are pretty good about sealing.

 

[gummycarbs]

I cleaned mine just for fun. It passed air just fine, though one side was maybe a little bit restricted. I sprayed some carb cleaner through until it came out clean and put it back in.

When I removed it, the threads were coated with that gray sealant that stays pliable.

 

[Proven]

I cleaned mine just for fun. It passed air just fine, though one side was maybe a little bit restricted. I sprayed some carb cleaner through until it came out clean and put it back in.

When I removed it, the threads were coated with that gray sealant that stays pliable.

was there anything wrong before you cleaned it, and was there anything better after?

 

[gummycarbs]

was there anything wrong before you cleaned it, and was there anything better after?

Nah, I'd already cleaned the intake as thoroughly as possible with it in-place, and my engine's been running great for the better part of a year now. I'd always wondered about that splitter/filter thing, though, so I figured why not.