Vacuum Line replacement


Changing the Vent Hoses

As posted by Bobbo on 8/27/2002 in a post entitled "Changing those pesky vacuum lines", it can prove to be a real nuisance when changing vacuum hoses on our Valks.
If you remove the air box, you will see that 3 vent hoses are connected to the intake manifolds. 2 of these, which are connected to carbs 3 and 4, are fastened via a T Connector (and another small hose) to the pair valve. You can see the pair valve with the T connector, etc. in the middle of the picture. The idea is to disconnect the hoses from carbs 3 and 4, and to tie a string to each of these. You can see these strings on each side of the picture. Disconnect the hose (in the middle) from the pair valve and pull everything upwards.

Note: These strings will enable you to pull the new hoses back into the appropriate places.

The third vent hose, which is used for the petcock valve under the fuel tank, is connected to carb 6.
The vents on carbs 1, 2 and 3 are blocked off by rubber vent caps .

String 'em: Side View

String 'em: Top View

Clone the Vent Hoses

Measure the hoses, cut new hoses of the same length, and connect these to a T fitting (new or existing one). Untie the strings from the old hoses, and tie them to the end of the new hoses. Carefully pull the strings to snake the new hoses back to carbs 3 and 4.

Connect the new hoses to carbs 3 and 4, and to the pair valve.

Note: Carb 6 is easy to do. Use a string in the same fashion as done above for the pair valve vents.

Clone the Bowl Vent Tubes Also

Since the air box was already removed, I decided to also change the small hoses that are connected to the carburators (on the same side as the enrichment valves).


5/32 hose was used instead of 3/16 (no clips required)
1/8 vent caps were used

Hats Off to rr

For patiently answering my numerous questions on the subject.