vacuum advance question
Thread Starter
Racer
Joined: Sep 2011
Posts: 414
Likes: 55
From: Humboldt county Ca
vacuum advance question
Yesterday I found that the advance weights on the 75, 350 were stuck. Lubed them and got them functioning again but found it possible to move the advance vacuum collar only a tiny bit. Unplugged the advance line and sucked on it----can hear the diaphragm clicking but no movement in the advance rod at all. Started engine and unplugged the advance line---no change in engine. Plugged the carb vacuum port----engine idles down slightly.
Does it sound like the vacuum advance is screwing up or is this the way these things work?
Since I collapsed my brain pan sucking on the vacuum line I'm now not able to think right and I need some help with this!
Thanks, Stump
Does it sound like the vacuum advance is screwing up or is this the way these things work?
Since I collapsed my brain pan sucking on the vacuum line I'm now not able to think right and I need some help with this!
Thanks, Stump
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,116
From: Crossville TN
Your vacuum can may be operational, but the advance plate in the distributor may be frozen so that the can will not cause any movement. The spring in the vacuum can is very strong and you have to apply engine vacuum level to get it to move much. You might be able to get it to move by 'sucking' on the hose...but you'd better have a good 'sucker'!
Try moving the plate by prying with a screwdriver. Or, you can disconnect the vacuum can and see how free the plate actually is.
Try moving the plate by prying with a screwdriver. Or, you can disconnect the vacuum can and see how free the plate actually is.
Safety Car
Joined: Oct 2000
Posts: 3,593
Likes: 103
From: Southern Indiana
My distributor weights didn't move either.
The dist shaft was gummed up stuck, I had my new dist waiting away so I changed it out.
Otherwise you can take off the cam gear and pull the middle rod out and clean and emery cloth it smooth
The dist shaft was gummed up stuck, I had my new dist waiting away so I changed it out.
Otherwise you can take off the cam gear and pull the middle rod out and clean and emery cloth it smooth
Thread Starter
Racer
Joined: Sep 2011
Posts: 414
Likes: 55
From: Humboldt county Ca
Thanks to everyone who replied. I took the screws out of the vac. can and checked the advance collar ------it moves freely now. Put a touch of lube on the advance weights and after reassembling I started the car. Vacuum now works right. I think maybe spraying the dist. shaft and weights with "DeepCreep" and letting it sit overnight finally loosened things up enough.
Thanks again!
Stump
Thanks again!
Stump
