Replacing vaccum advance..

[Citizen Rider]

How hard is replacing the vaccum advance?

Mines no longer working and it needs to be fixed. What all is involved? can this be done by someone with minimal knowledge of engines? Driveway swap?

Any info on doing this would be great, i cant seem to find my haynes manual...

 

[hack500]

here's a good explanation. I presume this is for an HEI if it's points then I guess it'd be along the same lines but don't know for certain.

it is quite easy to do. having an old distributor cap that you can cut in half will make it even easier. and do not turn the engine at all until it's back together.

step 1:
pull off cap with wires still attached. disconnect vacuum line.

step 2:
cut old cap in half about the height of the rotor.

step 3:
mark (#1)distributor body and engine block - use something easily visible and something that won't smudge or move readily then put on the cut cap then mark (#2) the position of the rotor to the cap.

step 4:
after you remove the distributor hold-down lift the distributor slightly and the rotor will turn then stop now mark (#3) this position of the rotor on the cap. then remove distributor. then remove cut cap

step 5:
with the distributor out remove the small roll pin from the shaft that holds the gear in place. be careful and don't lose it unless you have spares and remove the small screws holding the vacuum advance to the distributor body.

step 6:
slide shaft upwards to allow the pickup to slide off the small rod of the vacuum advance then the vacuum advance can be removed and the new one installed.

step 7:
put the gear back onto the shaft and the screws in for the vacuum advance. put cut-cap back on.

step 8:
when you get to putting the distributor back in just line up the rotor to the third mark on the cap and when the distributor is finally seated marks 1 and 2 should be in the right spots. if not then pull it out and re-align until marks 1 and 2 are correct.

step 9:
tighten the hold-down then put the good cap with wires back on and re-attach vacuum line.

step 10: you're done.

see? it's quite easy. I've heard of some people doing this without removing the distributor but I have no idea how.

 

[caseyk]

HEI?

It's easy to do without removing distributor...

Remove the cap, wires attached and move out of the way.

Remove the rotor and set aside.

Remove the vacuum line from the canister.

Unscrew the screws holding the vacuum advance to the distributor body (one in front, one in back).

Pull the vacuum advance canister towards you and twist it clockwise and it should come out. You don't have to be gentle with it.

Reverse the removal process to install a new one.

Retime the engine.

I've done this a few times without removing the rotor too.

 

[Citizen Rider]

Correct HEI. Damn, i wish i knew more about engines. I really hope i dont end up doing more harm than good.

Whats the proper way of timing with vaccum advance. Ive heard to pull off the vaccum and time it?

 

[caseyk]

Correct, pull the vacuum tube, plug the hole that connects to the manifold, then time the engine.

 

[BigBen]

Just like caseyk said, it isn't that hard.

Just watch what is going on when you pull the advance... The screws go through the "plate" part of the advance, and there is a bent rod in the middle. The tip of the rod hooks into the stator of the distributor.

You have to 'turn' it clockwise to get the rod out of the stator. Make sure that the bent tip of the new rod is in the hole when you get done installing the new one.

It's not that hard if you take your time and pay attenttion. The hardest part is reaching all the way back there!

-Ben

 

[diesel4me]

just did one!..

I just swapped a "good used" vacuum advance canister on my 305 a few weeks ago...did it without pulling the dizzy out,but it wasn't fun,since the dizzy is about 2" away from being behind the RADIO!...had to lay a plank on a blanket across the fenders to lie on while I did it,so I wouldn't bend brake lines ,or rip radiator hoses out of the radiator by leaning or stepping on them..

I'd suggest having a manet handy,your BOUND to drop the screws into the distributor,or onto the bellhousing,never to be seen again! ..

I dropped the nutdriver I used to remove the rotor screws,and it landed about 1" from the positive battery cable on the starter solenoid,and it took a half hour of F'n around to get it out again!--was lucky it didnt short out and cause a BIG headache!..so I'd remove the battery + or - cables first!..

I'd yank the dizzy right out to do the next one,I'm not as limber as I used to be!..but its do-able with it installed,just a PITA to get at..

You wont have to pull the shaft out of the dizzy to replace the vacuum canister,only need to do that to replace the pick up coil...