96-99 CPI Truck throttle body INLET gasket

[el torro]

Hello all. I'm a long-time lurker here.

Background, my son bought a 98 c3500 2WD 5.7 last year (after I told him it was a money pit ) and I have come here extensively for knowledge to fix things. The last time owned one of these trucks was 2004 when I traded my 96 extended cab 1500 for a 2002 Sierra 2500. So it's been a loooong time since I've turned a wrench on a GMT400. Thank you to all who have posted how-to guides and other information.

A problem I ran into recently is the gasket on the clean air side of the throttle body that seals it to the plastic intake was trashed causing enough of a vacuum leak to throw a MAF code. And of course, GM doesn't sell the part anymore and no one in the aftermarket has stepped up to make it. As a temporary fix, one of the dozens of previous owners used RTV to seal it. The problem there is if you take the intake ducting on and off diagnosing problems the RTV is no good after the first time, and it looks like garbage.

I found a thread somewhere that someone used a stack of square-cut o-rings glued together and said it worked. I wasn't able to find the right size o-rings locally for that. So I turned to my 3D printer.

I made a simple design in Fusion 360 and printed it out of flexible TPU filament. TPU is gasoline-resistant and has a melting point of 225° Celsius (437° Fahrenheit). The part has been performing exactly as it should for the last month.

If anyone is interested in the 3mf file I'll post it. I'm considering putting these in my Etsy shop as well, if I do sell them I'll still offer the file for free. As far a a color selection it might be what I can get my hands on the cheapest to keep the cost down since this is not a visible part. The pics I'm uploading are a semitransparent red color because that was what I had the most of lying around.

 

[L31MaxExpress]

Hello all. I'm a long-time lurker here.

Background, my son bought a 98 c3500 2WD 5.7 last year (after I told him it was a money pit ) and I have come here extensively for knowledge to fix things. The last time owned one of these trucks was 2004 when I traded my 96 extended cab 1500 for a 2002 Sierra 2500. So it's been a loooong time since I've turned a wrench on a GMT400. Thank you to all who have posted how-to guides and other information.

A problem I ran into recently is the gasket on the clean air side of the throttle body that seals it to the plastic intake was trashed causing enough of a vacuum leak to throw a MAF code. And of course, GM doesn't sell the part anymore and no one in the aftermarket has stepped up to make it. As a temporary fix, one of the dozens of previous owners used RTV to seal it. The problem there is if you take the intake ducting on and off diagnosing problems the RTV is no good after the first time, and it looks like garbage.

I found a thread somewhere that someone used a stack of square-cut o-rings glued together and said it worked. I wasn't able to find the right size o-rings locally for that. So I turned to my 3D printer.

I made a simple design in Fusion 360 and printed it out of flexible TPU filament. TPU is gasoline-resistant and has a melting point of 225° Celsius (437° Fahrenheit). The part has been performing exactly as it should for the last month.

If anyone is interested in the 3mf file I'll post it. I'm considering putting these in my Etsy shop as well, if I do sell them I'll still offer the file for free. As far a a color selection it might be what I can get my hands on the cheapest to keep the cost down since this is not a visible part. The pics I'm uploading are a semitransparent red color because that was what I had the most of lying around.

I bet you would end up printing a bunch of them if you offered them. EVERYTHING with that style of air intake uses the same unit. In addition to the GMT400 trucks the S10s, Astro vans, Fullsize vans through 2002 with the V8 and 2013 with the V6, the V6 and 350 V8 GMT800s all use the same sealing ring. I looked in the cataloging for all of them trying to find one for my 1997 Express prior to buying a new adapter hat from GM for the 2013 V6 van while they were still available.

 

[Caman96]

Agreed^^^I want one! I’m now “Watching” this thread.

 

[L31MaxExpress]

Also meant to throw out there, who cares what color it is printed out of as long as it corrects the un-metered air leak and holds up for years to come. Depending on the cost, I would probably buy like 5 of them just to have them in my toolbox and make the shipping cost worth it.

 

[el torro]

I didn’t think this would get as much interest as it is. Thanks guys. I’m thinking about pricing them at $5 for two plus shipping. So around $10 total. I can always do more than 2 and make a price break because shipping is going to be about $5 no matter how many I jam into a padded envelope.

 

[evilunclegrimace]

I didn’t think this would get as much interest as it is. Thanks guys. I’m thinking about pricing them at $5 for two plus shipping. So around $10 total. I can always do more than 2 and make a price break because shipping is going to be about $5 no matter how many I jam into a padded envelope.

When you get everything worked out let me know, I will gladly buy a few for spares.

 

[caw_86]

Interested as well

 

[df2x4]

I'd be in for a few spares as well.

EDIT - And I actually like the red color, sporty!

 

[el torro]

Quick update. I'm printing gaskets right now. I should have some ready to ship by next Monday as long as my printer behaves. Unfortunately, I won't have time to get anything packaged and dropped off at the post office before next Monday afternoon. I won't send a PayPal link before I'm sure I can get your items in the mail within 24 hours of getting paid. If you are interested in buying a few of these send me a DM with your PayPal contact info, your mailing address, and how many you want.

I'm honoring my original price of $5 for two gaskets and $5 shipped for a total of $10. If you want more than 2 gaskets I'll discount each additional gasket 50 cents up to 8 additional gaskets. So if you order 10 total gaskets your total cost with shipping would be $26 to your front door. 10 gaskets are what I am estimating I can fit in a reused Amazon bubble envelope before the shipping cost goes up.

I'm setting a cut-off date of September 6, 2024, for orders here. I'll re-open my Etsy store on September 9, 2024, and the price will go up to $5 each. The shipping cost will be a $5.50 flat rate for up to 10 gaskets for all US and US Territory orders. I'm still working on an international shipping price.

As far as colors, they are all going to be red until I use up the rolls of red filament on hand. After that there is no telling what color they will be, but most likely it will be black or orange depending on what is available and keeps the cost in check.

 

[Caman96]

Hello all. I'm a long-time lurker here.

Background, my son bought a 98 c3500 2WD 5.7 last year (after I told him it was a money pit ) and I have come here extensively for knowledge to fix things. The last time owned one of these trucks was 2004 when I traded my 96 extended cab 1500 for a 2002 Sierra 2500. So it's been a loooong time since I've turned a wrench on a GMT400. Thank you to all who have posted how-to guides and other information.

A problem I ran into recently is the gasket on the clean air side of the throttle body that seals it to the plastic intake was trashed causing enough of a vacuum leak to throw a MAF code. And of course, GM doesn't sell the part anymore and no one in the aftermarket has stepped up to make it. As a temporary fix, one of the dozens of previous owners used RTV to seal it. The problem there is if you take the intake ducting on and off diagnosing problems the RTV is no good after the first time, and it looks like garbage.

I found a thread somewhere that someone used a stack of square-cut o-rings glued together and said it worked. I wasn't able to find the right size o-rings locally for that. So I turned to my 3D printer.

I made a simple design in Fusion 360 and printed it out of flexible TPU filament. TPU is gasoline-resistant and has a melting point of 225° Celsius (437° Fahrenheit). The part has been performing exactly as it should for the last month.

If anyone is interested in the 3mf file I'll post it. I'm considering putting these in my Etsy shop as well, if I do sell them I'll still offer the file for free. As far a a color selection it might be what I can get my hands on the cheapest to keep the cost down since this is not a visible part. The pics I'm uploading are a semitransparent red color because that was what I had the most of lying around.

Is the material you used the TPU 90A?

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Either would probably be fine.