A common sense approach to ending engine leaks once and for all
Jim Smart - August 30, 2012 10:00 AM
A gasket’s purpose all by itself is to seal in fluids, vacuum, and pressure. With the clamping force of fasteners, a gasket should fill in the gaps. When you have surfaces you cannot perfect, sealer should be used sparingly, and we mean hair thin — a light bead that fills irregularities without oozing out. Around fluid passages is suggested, but minimal. And by the way, trim your paper gaskets.
We tend to laugh at this old yellow goop today, but good old-fashioned Gasgacinch is a time-proven gasket helper which has been around for more than 50 years. We’ve no idea what it is made of. However, we know it works. Just a thin film of it around coolant passages and intake ports provides outstanding performance. Apply and wait until just tacky, then carefully install the gasket.
Good sealing begins with perfect surfaces. Warped and pitted decks can leak. Warping and pitting needs to be checked with a straight edge and dial indicator and milled as necessary.
During assembly, surfaces need a good wipe down to remove debris prior to gasket installation. Debris includes any kind of oil, including skin oil. Although a shop towel is being used here for wipe down, it is suggested you use a lint-free tack rag for optimum results.
To minimize leak risk with older engines, it is suggested you go with today’s high-tech head and intake gaskets with silicone sealing around coolant and intake passages. Fel-Pro’s Print-O-Seal head and intake manifold gaskets offer outstanding leak protection and are worth the difference in cost. Make sure you are getting Print-O-Seal because not allFel-Pro sets have this premium feature.
Never use steel freeze plugs, which will rust through in time. Always use brass. Use The Right Stuff from Permatex and use the widest freeze plug lip available for good penetration. MCE Engines in Los Angeles, California, uses JB Weld to secure freeze plugs for optimum results.
Rear main seals can be a huge pain in the neck, which is why they call for close attention during installation. Originally, most rear main seals were rope. Today, we have two-piece rubber lip seals. Stagger seal ends away from main cap parting surfaces for best results. Before main cap installation, use The Right Stuff at parting surfaces and around seal tips.
Some applications that originally had rope seals also had a retaining pin. If this pin is still there, it distorts rubber rear main seals causing leaks. Make sure this pin has been removed.
Seals need all kinds of help in order to do their job. Proper installation is what determines if a seal functions and lasts. Before installation, apply a thin film of The Right Stuff around the seal pocket’s perimeter. Drive the seal in carefully with a seal driver.
When you’re installing a harmonic balancer, pulley or axle shaft, apply generous amounts of lube on seal contact surfaces. Use an installation tool, not a sledgehammer, for proper installation and seal protection. Gently and smoothly install the part. If the seal employs a retention spring, make sure the spring is there.
Oil pan gaskets drive people crazy. However, take heart, there are solutions. Install side rail gaskets first, with a thin film of Gasgacinch between gasket and engine pan rail. Apply The Right Stuff between end and rail gaskets as shown here. End gaskets mandate extra care to ensure they’re properly seated. For more popular applications, Fel-Pro offers a one-piece urethane oil pan gasket that makes replacement easier than ever before.
Always trim gasket overhang, especially where gaskets meet.
Spend the extra money on Fel-Pro Print-O-Seal intake manifold and head gaskets. Silicone seals fill in irregularities to prevent potential leaks.
Although gasket makers include intake manifold end gaskets, it is suggested you not use them. A bead of The Right Stuff at manifold end rails works fine and seals up as it cures. This is an example of too much sealer.
When you torque a vee-type intake manifold on a V-6 or V-8, follow manufacturer’s torque specifications and tightening order to the letter. Do not overtighten. Tighten bolts in third torque values. Once you are finished, go back check total torque, but do not go any tighter.
This telltale head gasket demonstrates the gasket is installed properly on a small-block Ford V-8. If you can’t see the gasket, it is installed backwards.
Valve cover gaskets should be secured to the valve cover with Gasgacinch or The Right Stuff. This makes removal for service much easier.
Internal leaks can bite you. Screw-in rocker arm studs often go directly into water jackets. Use industrial Teflon sealer or The Right Stuff on these stud threads, torque to manufacturer’s specifications, and allow curing for 24 hours.
It’s those pesky oil, antifreeze, and transmission fluid spots on the garage floor that get us thinking about what to do about classic car engine and driveline leaks.
Automakers around the world produce new vehicles today that can go more than 100,000 miles without driveway spotting. In fact, it is so good most new vehicles operate a lifetime without leaks of any kind. So why is it we can’t restore a vintage car without the disappointment of engine and driveline leaks?
The answer lies in gasket and seal technology, along with how we prepare engines and components for assembly. You have to have perfect contact surfaces void of irregularities to have a fighting chance against leaks. You also want a surface free of old gasket material and sealer. Even the smallest trace of sealer or gasket can cause leaks. And when you apply sealer, forget thinking more is better. A gasket’s purpose is to seal — keeping fluids inside and contaminants outside. That means you should respect the gasket’s primary job and use sealer sparingly and only as necessary.
Time and time again, we see excessive amounts of sealer on both sides of gaskets. Stop that! The only reason you should ever use sealer is as an aid to gasket sealing, which means extremely modest amounts of sealer, if at all. So how do you achieve leak-free operation? Drag your cursor over the images above to read more!