1968-1969 Ford and Mercury - VACUUM SCHEMATIC FOR 69 428CJ R CODE

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VACUUM SCHEMATIC FOR 69 428CJ R CODE

Printed From: The Ford Torino Page
Category: Model Specific Forum
Forum Name: 1968-1969 Ford and Mercury
Forum Description: Technical discussion for 1968-1969 Ford and Mercury
URL: https://forum.grantorinosport.org/forum_posts.asp?TID=21502
Printed Date: 26-March-2026 at 5:42PM
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Topic: VACUUM SCHEMATIC FOR 69 428CJ R CODE

Posted By: ELT
Subject: VACUUM SCHEMATIC FOR 69 428CJ R CODE
Date Posted: 19-December-2024 at 5:45AM

Hi all, I am in the process to get all the vacuum lines correct on my 69 428CJ R CODE automatic C6 with factory air and original Holley carb. In the manual, volume 2, page 09-01-18 has the schematic(bottom one). Two questions...

1. Where is the air bypass valve? I don't find it in my engine compartment. The pic shows what looks like 3 hose connections on the valve along with a vacuum connection. I have three hose connections on my water valve along with 2 vacuum connections but the vacuum connections are for the lines coming through the firewall.

2. The schematic shows the yellow stripe line going to the carb. Does it go to the front diaphragm port on the passenger side?

Clarification on this would be much appreciated. Thank you!!

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Thanks,Ed

Replies:

Posted By: schufitz
Date Posted: 19-December-2024 at 8:33AM

Do you still have the smog pump and associated belt/hoses/air injectors at the exhaust manifold? The air bypass was part of that system, and those components were usually removed back then as it was a drag on performance, and they are not cheap to replace these days.

See the Hot Rod article in the link below. Note section 14. It goes into details about the system.

https://www.motortrend.com/how-to/1803-428-cobra-jet-engine-detailing-part-2/" rel="nofollow - 428 Cobra Jet Engine Detailing, Part 2

Great document:

https://anghelrestorations.com/wp-content/uploads/2021/09/cobrajet_engine_detail_v1.3.pdf" rel="nofollow - cobrajet_engine_detail_v1.3.pdf

If you google the Ford thermactor system, there are lots of good articles/pics/explanations.

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Dave
1969 Torino GT/351W 2V/FMX/Vinyl Top/Black Jade/Gold Stripes/Nugget Gold Buckets/Console/Racing Mirrors/AC/PS/PDB

Posted By: ELT
Date Posted: 19-December-2024 at 9:53AM

Wasn't the smog pump for California cars? My car was delivered to Texas and spent it's life there until I bought it. Are you saying that the air bypass valve is only for thermactor emission cars?

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Thanks,Ed

Posted By: ELT
Date Posted: 19-December-2024 at 10:17AM

I just read on one of your great links that all US cars had the smog system. Thank you for that. Still learning! As much as I want to bring things back to original, I will do so without replacing that system. So, does the yellow line go to the vacuum port on the passenger side in front of the choke on the carb?

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Thanks,Ed

Posted By: ELT
Date Posted: 19-December-2024 at 3:32PM

Took a good look at the original carb. It's the only vacuum port so that must be where the yellow striped hose attaches.

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Thanks,Ed