My Carb Vacuum Cover Fix - Top Cover Fix

[keddano]

This can fix a Vacuum Cover with a totally destroyed plastic cap. Because the carbs need to operate in perfect balance and harmony, I suggest that you do all 4 carbs,if you do one. Also with this fix you have access to make sure the passage is open that allows vacuum to operate the slides. If the caps are just cracked, the the epoxy way would be best. In my case, 2 of the caps were totally destoryed,one someone had filled the cavity with JB weld and had the passage totally sealed off.

I will walk thru the simple and easy steps to what I think is a perfect fix. That looks like a factory job when done.
Here was one of the carbs I started with.

And the .50 cent solution.

[keddano]

The plastic plug is swagged into the bowl,but the rollover lip is very small.
So the first thing to do is remove the broken plug completely, This can be done a few different ways, I did mine using a soldering gun to melt it some, so I could get a screwdriver blade under it and pop it out. You could also use a dremal with care. Using the solding gun, do it in open air,as the smoke is strong and burns the eyes. use care not to damage the inner surface. there is a thin rubber seal under the plastic cap.

With the cap out you can check the passage and see that it is clear and clean the surface that was under the cap.

A small paper clip can pass thru the passage with the cap off.

[keddano]

I purchased 4 Dorman Freeze Plugs from O'Relly's for .49 cents each. The part # is 555-018 they are considered a 1" plug. (The ones I got measured with calipers 1.025" in Dia.)

The opening were the plastic cap was is just under 1" with the rolled flange,(They measure Appox. 0.990) so the plug doesn't fit. All that was needed was to remove the rolled over lip with a 1" dia 1/4" shank grinding disc, I think mine came from Harbor Freight. I chucked it into the drill press and carefully moved the bowl around to grind the slight lip open more.

Note: I placed a 1/2" flat washer into the pocket while grinding the opening to protect the bowl surface where the port is.

With the plug off, you can clearly see thru the Bore that the slide shaft rides in, I used a thin strip of (Type S Ultra Fine) gray colored Scotch-Brite with a wooden pencil to lightly polish the bore.

[keddano]

The advantage of using the domed shape freeze plug is it gives you room for the center shaft on the slide to fully open, that is the reason the plastic cap has a BUMP in the center, so if you used a nickle/quarter straight across the top of the flange, you are stopping the slide short of the full open position, not much,but some.

[keddano]

The only thing left is to seal the plug into the cover. Care has to be taken to prevent whatever you use from seeping into the vacuum port. You could use epoxy around the lip, silicone, or aviation form a gasket. Just don't let whatever you use seep under the cap.
(Since I'm going to order the brass plugs, I haven't sealed them yet. I'm leaning towards using Black silicone, the fit is so close, you would never see it, Also if for some reason in the future you want to remove the cap, it would be easier to remove then epoxy.)

Dorman plugs also come in brass, That would really look good polished on top of the polished cover.

They told me at O'Relly's they could order them for me.
They cost $1.69 each
http://www.oreillyauto.com/site/c/detai ... &ppt=C0332

[keddano]

http://www.dormanproducts.com/da-28415-555-018.aspx

Here is the specs on the plug.

it fits: 2005 CHEVROLET IMPALA V6 - 3.8L (231 CID): GAS: FI: N: K

Expansion Plugs, Cup Type Expansion Plugs
555-018 1.000"
Nominal Dia. : 25.73mm SC
Metric Dia. : 25.73mm SC
Type : Steel
Height : 0.250"
Closed End Dia. : 1.007"
Open End Dia. : 1.021"
Brand : Dorman - AutoGrade - Boxed

Here is the brass one:

http://www.dormanproducts.com/p-22177-565-0181.aspx

Dorman part # 565-018.1
565-018.1 1.000"
Nominal Dia. : 25.73mm
Metric Dia. : 25.73mm
Type : Brass
Height : 0.270"
Closed End Dia. : 1.007"
Open End Dia. : 1.018"
Brand : Dorman - AutoGrade - Bagged

005 CHEVROLET IMPALA: LS V6 - 3.8L (231 CID): GAS: FI: N: K
• 25.73mm Brass Shallow Cup

[keddano]

That is it.... for $2.00 a full set of covers could be repaired, plus you could also cover the plugs with the cool Logo Caps that wingovation sells if you want.

If anyone can see a problem with this approach, let me know, to me it seems the best fix for a destroyed plug.

Also if it merits it, feel free to move it to the How to for wings.

[kb0ou]

Nice write up, looks like it would work good. Think the Brass ones would look good.

John

[Whiskerfish]

Very very nice job and documentation

[RB]

Move to How to???

[Toehead]

Nominate for shoptalk!

[Bankerdanny]

Well done. You can also polish them up for a nice finished look.

[rogue1000]

Nice! I like old coins, but your way is better...the brass would look nice, and keep shiny longer.

[keddano]

Like Randakk has pointed out, The bowl and slide are matched at the factory for weight and fit tolerances. Also matched in pairs for each side of the engine. As time goes on,more and more sets will be tossed away because of one bad plug, And these maybe worth gold weight one day when they are harder to fine.

[Fred Camper]

Nice addition to shop talk, sure seems to be the right answer.