Changing valve-cover gaskets on a 7.5-liter Ford V-8

factoid

This is a hardy old bucket. The motor’s in good shape (76, this 000 local miles), medical the transmission whines and leaks but still has plenty of life in it. It has new brakes and tires, and feels rock-solid.

But the motor leaks like a sieve, so I thought I would tackle the only leak-plugging task I’m capable of without an engine hoist and a ton of spare time – replacing the leaky valve cover gaskets.

I learned how to do this on an old four-banger Volvo B-18 engine 25 years ago, from a mechanic who had trained with shade-tree tough-guys in South Africa.

Here’s how it goes:

Remove the engine cover.

And behold: the 460-cubic-inch Ford V-8. This is a beast – even for a van – 7.5-liter displacement for those of you who think metric.


This long, gnarly orange tube appears to be the throttle control.

Pull the air cleaner and HEY! Surprise! We have a brand-new Holley carburetor under there. This van was a bargain at $1500.

Here’s the smog plate, containing all the vital stats on a 7.5-liter V8 that the California DMV holds holy for pollution-control purposes.

Make sure to mark off the nest of snakes that was the smog gear of 1985. Otherwise you’ll have a hard time reassembling everything later.

There are a few obscure vacuum hoses connected down near the oil pan, too – you have to reach for ’em.

Pull the spark plug wires – That tire back there (the spare) is actually sitting where the passenger seat would. The van came without one – we’re heading out to a junkyard tomorrow to try to find one.

Also, mark the sequence of the ignition wires with a label on the valve cover.


Then commence to unbolting the covers.

alienrobot, who took all the pictures (thanks, kiddo!) wanted to get a shot of my filthy paws.

Reaching through the engine tunnel to get the middle bolts.

After a few attempts at prying off the end, I realize I should be applying more even pressure, grab the middle of the long edge and pull – and the cover pops off.

Hauling the right cover out of the engine bay.

The original cork gasket is brittle and peels out pretty easily, considering how compressed it is by years of over-tightening.

Scraping the broken bits of it out of the end – wouldn’t want these sucked into the motor.

Now the left cover.

Then scrape the faint residue of gasket adhesive out.

Clean ’em up. If I had time, I’d strip them, sand them and paint them, but we need to be able to drive the van to the junkyard tomorrow to lug any seats home.

Use engine degreaser to clean out the inside of the cover, then lay down a trail of black gasket caulk.

A thin but even coat of the stuff is all you need – it’ll goosh out quite a bit when you …

… flatten the new gasket into place. Gently, now, because you want to have some compression left in the whole thing when you seat it in place. If you moosh it flat here, you run the risk of uneven seating – and thus leaks.

A thin coating of axle grease on the underside of the now-seated gaskets guarantees that you’ll be able to pull the cover off and replace it easily.

This is particularly useful when you want to pull the covers off to adjust the valves.

Next, clean off the top of the heads  – the side that will meet the greased gasket.

I am now officially an engine geek. The left one is all prepped, now do the right one.

Let the goop dry for a half hour or so – enough to put a skin on it, and then put back the covers. Here’s the right one

… and the left …

Then, start bolting them down again – snug all the bolts down, just finger-tight so that the pressure on the gasket is even.

Ahem:

When bolting down the left head, it’s best not to DROP YOUR SOCKET AND EXTENSION BAR IN THROUGH THE OIL-FILLER HOLE.

Fishing with fingers proves futile. The good news is the area below the oil-filler hole is walled off so the socket and 4-inch bar – while fully gone from view, can’t tip over sideways out of reach, which would otherwise guarantee having to completely remove this cover, clean it off and redo it.

Nope, it takes a pair of needle nose pliers, a fair amount of cursing and what alienrobot says is an evil grin.

Thus bolted down, the covers are now fully gasketed. There is only to reassemble the spaghetti farm …

Start her up to make sure she runs, and then retire to a good drink and contemplate whether to burn one’s jeans.


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