Leaks leaks and more leaks

Looking for tips and tricks to stop valve cover oil, and transmission fluid leaks on a FE 428. May also have a transmission cooler hose leak, fuel line leak, and power steering pump and hose leak but not sure yet. Too many things leaking. Looking for tips and advice. If you can help let me know. New engine new parts lots of leaks. DIdn’t leak before but leaks now after engine replacement.

if the transmission oil pan is leaking. Get Lube locker gasket. They’re awsome and will stop leaks from the trans pan gasket. https://www.summitracing.com/parts/lub-llt-f0c6

For the valve cover gaskets usually the cork gaskets will do the job. But, if you’re having leak problems try a pair of rubber gaskets and clean both surfaces and apply RTV when installing. https://www.summitracing.com/parts/mah-vs38308r/make/mercury/model/cougar/year/1967

Ah yes I remember lube locker gaskets now will do. Has cork valve cover gaskets with very small dabs of RTV around the hole areas. I read something somewhere about the intake gasket sticking up and not allowing the valve cover gasket to fully seal and needing to be filed down. Is this something to be considered? What about cork gaskets with RTV on both sides?

Lots of variables but my old 390 doesn’t like the oil pan full. Running it midway between full and add 1QT. I suspect that the rockers get excess oil because of a high volume pump.

If you have minor seeping it may just resolve itself by using the vehicle often. That’s my experience for a lower radiator hose on a crusty water pump

Transmission pans can be flimsy and will leak if overtightened. Also note that power steering and transmission use the same fluid. As such, it’s possible for a misdiagnosis of the source.

I guess just be observant about how large the leaks are deal with them. Is it really a damaged or improper gasket? Or perhaps a seal that is overwhelmed?

For certain the valve cover surface needs to be flat and clean for the gasket to work. The intake gasket are trimmed and/or lightly hammered flush. I’ve used a sealer between the valve cover and gasket to hold it in place but also some sealer around the bolt holes on the engine side. Just don’t glue the gasket to the engine as maintenance would be more troublesome.

The cork valve cover gaskets work better than any other kind. They leak if overtightened, the valve cover bends easily. Make sure the valve cover is straight, glue the gaskets to the valve covers with contact cement. A dab of silicone (Right Stuff is one brand) at each intake gasket is all that is needed. Torque the valve covers to the specification in the shop manual.

PS pumps, valves, hoses are good for maybe 15 - 20 years. I just got through rebuilding or replacing all that stuff on my GT-E. I had not touched it since I first restored the car in 1994. It is sometimes time to do it all once and do it right. I rebuilt the alternator, the fuel pump, and the water pump. Replaced the starter Bendix with a new Autolite unit. New radiator and heater hoses. Fresh paint on everything under the hood.

You might consider a similar approach so that once you get done you won’t need to worry about anything for the next 20 years.

I’ve had no problems with the cork gaskets either, but agree there is a tendency to ovetighten and deform the valve cover or pan lips. Mine didn’t leak a drop when I got it back from engine overhaul - except for the rear crankshaft seal which leaked a lot. Mechanic pulled the crank from below and fixed it. I also fought a power steering pump leak for years before finally replacing the pump front casting to fix it. Now the power steering ram cylinder shaft seal has started leaking - hopefully easy to fix. The differential has dripped since I’ve owned it. Replaced pinion front seal, but still leaks. Not easy to get these old cars leak-free, but can be done. Just takes more time and money.

These weren’t overtightened. When I got it back it leaked so I torqued to 7 ft/lb. They were loose. Think it says somewhere 4-7 or 5-8. Still leaked. Pulled off and tried Indian head shellac in the lower parts where oil sits and there aren’t any bolts around the lower corners. Sealed back up torqued to spec let it sit for a few days still leaks. It may have extra oil in it possibly 6 or 7 quarts to compensate for not being able to use a windage tray. Will also say it has a ton of oil pressure.

If the cork gaskets are 25 years old and shrunken you may need to just replace them.


They are about a month old.

OK then bad installation technique obviously.

Were all gasket surfaces shiny clean and smooth with all contaminants removed? I get them squeaky clean with scraper and scotch brite, then use lacquer thinner as final step in cleaning process.

I didn’t install them initially but it looked to be well done. I use a similar technique but use simple green. I can tell it is leaking right at the lower back on both sides down onto the exhaust pipes. Where Ford didn’t put any bolts and where oil will sit and pool in the heads. Maybe a combination of bad technique but also a bad design. Plus this engine may have a higher amount of oil and it definitely has higher oil pressure than the last one. Gauge use to be in the middle now it’s closer to 90 than 45.

Others on here have more experience than I do on oil distribution, but I can’t imagine a standard pressure oil pump could pump enough oil into valve covers to flood them unless the oil drain holes are plugged.

I don’t have leaks there. My 428CJ runs 65 PSI cold, settles down to 50 PSI at idle hot. My 427 runs about 100 PSI cold and 70 PSI hot.

The cork valve cover gaskets can be re - used once but I tend to wipe the gasket surface and the head and intake with lacquer thinner or MEK. Then a dot of RTV on each mating surface where the intake meets the head. The gasket is glued to the valve cover with 3M 1357 contact cement. I don’t think Simple Green is going to be effective here.


Ok I’ll give that a shot. That’s exactly how these were installed except for the glue on the valve cover side. There was a small amount of RTV at each of the 5 bolt mating surfaces on the head side of the VC gasket. The intake to head gasket sticks up slightly above the intake and head at the front most and rear most point of contact. I may trim/cut or grind that down and make it as even and level as possible. If I choose to reuse the cork gaskets what’s the best way to clean the oil residue off of those?

Agree on Simple Green - not strong enough. Use lacquer thinner to make sure all traces of chemicals and sealers are removed from all gasket surfaces and gaskets themselves. I think I would invest in new cork gaskets if I were redoing this.

If I choose to reuse the cork gaskets what’s the best way to clean the oil residue off of those?

See edit on my previous post.

I think gasket sealant on the valve cover side is the key. Royce uses contact cement, I use yellow gasket sealer, but something is needed here since the thin valve cover tends to deform as the bolts are tightened. The head surface by comparison is flat, stays flat, and bites into the gasket for a good seal.

I use Gasgacinch to glue valve cover gaskets to the valve covers. It is a thinner form of contact cement. Also good on both sides of thin gaskets such as thermostat housing, timing cover etc.

No RTV anywhere on valve covers, just in the corners on the block where intake manifold side and end gaskets meet.

Follow Royce’s reccomendations.