TR2/3/3A Dist vacuum pipe to carb.....

[karls59tr]

Anyone know anything about there being two different pipe attachment methods at the SU carb end?

 

[karls59tr]

I found out there are 4 different assemblies for the vacuum pipe. See the Moss catalogue.

 

[Snowkilts]

There may have been different carb bodies too. I discovered mine was leaking and found that the threads were bottoming out before the fitting seated. I ended up having to file off some of the boss on the carb which solved the problem.

Either that or somebody put a non-standard fitting on the line at some point. The threads fit perfectly though. I would suggest testing both ends with a vacuum pump. Put the pump on the carb end and make sure that the advance activates and holds until you release pressure. Then put the pump on the distributor end and put your finger over the hole in the carb body (air cleaner off, obviously). Make sure it hold vacuum until you take your finger off.

 

[karls59tr]

Thanks for the response. I posted this because a guy I know who is restoring his Tr3 phoned me the other day asking about why the threaded fitting would not go into the carb? I think he said the vacuum line was new? I recall when I did this on my 3 I had to play around with the fitting before it would screw in straight. Also I believe the Tr4 Su's are supposed to have a different setup there Maybe he has TR4 Su's on his 3 or a poorly made aftermarket part?

 

[mrv8q]

I just encountered this a couple of weeks ago, replacing the old vacuum line with a new one from MOSS. The threaded carb fitting looked like the original but wouldn’t screw in. I wound up using the old fittings and olives.

 

[TRopic6]

Here's how it attaches to the underside of the front carb in my mid-TR3A. Earlier cars had a brass union in the carb and the line has a screw-on fitting like is used on the vacuum advance. Maybe that was for the TR2 - I have one and will add a picture when I find it.