2F Carb return line fitting thread size and pitch. (1 Viewer)

[Helimancan]

Anyone happen to know what the return line fitting thread and pitch is ?

I would like to find a suitable plug and don't have access to my carburetor for the next couple weeks.

Thanks !

 

[lcwizard]

isn't the return line on your fuel pump?

 

[lcwizard]

 

[Helimancan]

isn't the return line on your fuel pump?

No it's on my carb

 

[lcwizard]

I've not seen that carb... @65swb45 ? @RAGINGMATT ?

 

[Helimancan]

I've not seen that carb... @65swb45 ? @RAGINGMATT ?

Thank you for the help !

It's a thing.. trust me
Not my carb. Just an online pic..
Still need to determine the diameter and thread to be able to plug the return line.

 

[lcwizard]

I've owned a lot of 40s and 60s and never had a carb with a return. the return was always on the fuel pump. the fuel pressure
regulator is built into the pump in that case. If you do have a return from the carb then there is a pressure regulator built into
that circuit. You could install an adjustable one directly into the retuen line. That's a common practice for Webers, Holleys, etc.

 

[Helimancan]

I've owned a lot of 40s and 60s and never had a carb with a return. the return was always on the fuel pump. the fuel pressure
regulator is built into the pump in that case. If you do have a return from the carb then there is a pressure regulator built into
that circuit. You could install an adjustable one directly into the retuen line. That's a common practice for Webers, Holleys, etc.

Again thank you for the help but that is not accurate.

Older model years did not use a pump with a return.

They had a carb with a return.

I have created this thread to find the diameter and thread pitch of the fuel return line fitting on the carburetor so that I can plug it. If anyone happens to know just holler.

 

[lcwizard]

I wish I could claim to know everything but like Ivan Stewart said "i learn something new everytime I get into the driver's seat".
( out of context).. I'll pass final judge ment to Jim , @FJ40Jim, or Mark , @65swb45

 

[lcwizard]

sorry, I thought you were dealing with a 2F. Which year had a return? I have a 73, 69 and an early single barrel, all without returns

 

[lcwizard]

I see the port you're talking about. It's drilled perpendicular to the feed port and a banjo fitting is placed between the plug and carb.
The banjo fitting is 12mm x 1.25 pitch. I found a '78 carb with that return. The other carbs just have a plug,. They use a copper washer
to seal

 

[Steamer]

Those fittings are compression type fittings. They use a nut, (compression nut) and a brass ferrule that slips onto the 8 mm tubing. 5/16” ferrules work also. The compression nuts are not any standard metric bolt thread. The have a size of their own. I just tried one and it screws onto an M12 x 1.5 but it’s very sloppy and not right. The pitch seems to be 1.5 but the diameter is bigger than M12. I don’t have anything in M13 x 1.5 to try and don’t even know if it exists. You could always make a cap with a nut, ferrule and a short piece of 8mm or 5/16” tube that’s soldered up closed.

 

[lcwizard]

Those fittings are compression type fittings. They use a nut, (compression nut) and a brass ferrule that slips onto the 8 mm tubing. 5/16” ferrules work also. The compression nuts are not any standard metric bolt thread. The have a size of their own. I just tried one and it screws onto an M12 x 1.5 but it’s very sloppy and not right. The pitch seems to be 1.5 but the diameter is bigger than M12. I don’t have anything in M13 x 1.5 to try and don’t even know if it exists. You could always make a cap with a nut, ferrule and a short piece of 8mm or 5/16” tube that’s soldered up closed.

There must be some variations. I pulled one off the '78 carb I have here. It's a banjo bolt, 12mm x 1.25 , with a port drilled up the center of about .05". The feed port is , as you say a compression fitting with ferrules. On the far side of this pic you can see a banjo fitting bolted perpendicular to the feed port. I'm guessing it was the early 2F, before the return was moved to the fuel pump.
The return was routed back rather than forward

 

[65swb45]

I never bothered to research the thread info for that item. On a need to know basis I determined that the cap plug on the 1F was/is 11mm.

 

[lcwizard]

So Mark, What years had return ports on the carb.

 

[73FJ40]

@lcwizard

 

[Steamer]

Wasn't clear on just where you want to plug or cap off at. Are you removing the banjo fitting and replacing the bolt that holds it on?
Or are you looking to cap off the end of the banjo fitting.
A or B ?

 

[73FJ40]

@Helimancan

In any event, the nut and ferrule (olive in Toyota lingo) are still available from a dealer:

Nut Union - Toyota (90402-13041) $6.21 list
Olive - Toyota (96395-71400) $4.22 list

Maybe you could use a short length of 8 mm rod (cut off piece of bolt?) with a new nut and olive to seal the return port?

 

[lcwizard]

@lcwizard
View attachment 2072268

View attachment 2072274

View attachment 2072275

View attachment 2072276

So he'd be looking for the 121811 in the third pic down. That one is the 12mm .125 pitch.
Any indication of the years on these or was it based on the market?

 

[73FJ40]

So he'd be looking for the 121811 in the third pic down. That one is the 12mm .125 pitch.
Any indication of the years on these or was it based on the market?

Um, the year, month and market are identified in the top left corner of most of the pics.

7602 = Feb 1976
CND = Canada
USA = well, I suppose you get it.

All of these fiche captures are from a North American parts list.

All of the parts are NLA.