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Engine Vacuum Caps

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BigBrother-84

Engine Vacuum Caps

Hi Gentlemen!

Yesterday, finished installing a NOS speed control "Dealer Installed Kit".

Had to plug the system to an free engine vacuum port. I took off one plug cap and discovered it was completely dry and cracked… although it looked good.

I share this in order to remind members that our trucks aren’t young and little things like that should be part of a regular renewal check list.

Easy to forget, but can interfere with engine performance.

Jeff / 1984 F350 Crew Cab 4x4/5.8L w351 4V/ T18/ D50 4.10 front/ 8' bed.
Restored 2019-2022.
Nicknamed «Big Brother 1984», due to its soooo-looong shape & nod to George Orwell's 1984 famous novel.

Gary Lewis

Re: Engine Vacuum Caps

Administrator

Thanks, Jeff. Glad you mentioned that.

Gary, AKA "Gary fellow": Profile

Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
Blue: 2015 F150 Platinum 4x4 SuperCrew wearing Blue Jeans & sporting a 3.5L EB & Max Tow
Big Blue: 1985 F250HD 4x4: 460/ZF5/3.55's, D60 w/Ox locker & 10.25 Sterling/Trutrac, Blue Top & Borgeson, & EEC-V MAF/SEFI

mat in tn

Re: Engine Vacuum Caps

please save yourself some headache, and some whining from bystanders about your "old dated crap" and by a pkg of brite colorful vinyl vacuum caps and not the available rubber ones. I know the colored ones may not look original, but they are as close to "set and forget" as these get. the rubber ones will do this again and again. and to be fussing on the road over a vacuum cap is just not worth it.

81-F150-Explorer

Re: Engine Vacuum Caps

I've been known to use a piece of Fuel Grade hose with a screw in it for a decent vacuum cap alternative.

The vacuum caps that are sold now days cannot handle the fuel vapor from the intake with the engine shut off. It's like running windshield washer hose, for the PCV or the vent line from the fuel tank. The Fuel vapor will rot them.

Truck: 1981 F-150 Explorer / Engine: 300-6 California MCU Feedback System / Trans: T-18 - 4 speed / 2.75 Ford Rear Axle Open Diff.

ArdWrknTrk

Re: Engine Vacuum Caps

Administrator

One might consider the silicone caps often sold to protect hose barbs and screw threads from powder coat.
They are pretty inert and easily handle the oven heat.
IDK if an assortment is available in all black but I see a few sets on Amazon that are color coded by size (1/8-1/2")

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

Gary Lewis

Re: Engine Vacuum Caps

Administrator

That's a good idea, Jim. I have a multi-colored set from Eastwood and they've held up well with powder coating so I'm sure they'd handle the underhood environment well.

Caplugs appear to sell things for masking, and their HVC Series comes in a wide range of sizes. They are vinyl but should stand the temp. And they offer free samples, so maybe someone wants to test them?

Gary, AKA "Gary fellow": Profile

grumpin

Re: Engine Vacuum Caps

I tried hypalon caps, then sold the truck. They were holding up good.

Maybe if Bryson sees this he can comment.

Dane
1986 F250HD SC XLT Lariat 4x4 460 C6-Sold
1992 Bronco XLT 4x4 351W E4OD
1998 GMC Sierra SLE K1500 350 4L60E
Arizona