If you’re wondering how to tell if your rear main seal is leaking, then your vehicle must be leaking something.  Before we get into the technical details of determining if you’ve got a rear main seal leak versus another type of oil leak, we need to be sure that it is indeed oil that your vehicle is leaking, not power steering fluid or transmission fluid or some other type of lubricant.  To be sure you’ve got an oil leak, try checking out our article on how to determine what your car is leaking.

Once you’re sure you’ve got an oil leak, we can help you figure out whether it is the rear main seal that is leaking or some other oil seal or gasket in your engine.

How to Tell If Your Rear Main Seal Is Leaking

• Are there any higher oil leaks?

• Are there drips from the bell housing?

• Is the oil pan gasket leaking?

• Is the flywheel or flexplate oily?

Since rear main seal leaks are uncommon on most vehicles it’s very possible that you’ve got another leak higher up on the motor that is dripping down and just looks like a rear main seal leak.  The most common leaks that can masquerade as a rear main seal leak is a valve cover gasket leak, intake manifold gasket leak or a distributor gasket leak.  If you find oil on your engine above the bellhousing, check for leaks at these locations.  If you find one, repair it, clean the engine and check for leaks again in a few hundred miles.

A rear main seal leak will cause oil to drip from the bottom of the bellhousing at the front of the transmission.  If you have drips coming from in front of the bellhousing, locate those leaks, stop them and clean the engine. After a few hundred miles you can check again for leaks to see if you still have any.

The most common leak that is confused as a rear main seal leak is an oil pan gasket leak at the rear of the engine.  The oil pan gasket is just below the rear main seal. An oil pan gasket is also usually much less expensive to replace so it’s important to check for leaks in your oil pan gasket before you jump to any conclusions.

The best way to prove that you’ve got a rear main seal leak is the check if the engine side of the flexplate or flywheel is oily.  If the rear main seal is leaking on your engine it will drip oil onto the flexplate or flywheel and sling oil around the bellhousing. Most engines have an inspection cover in the bellhousing the allow you to check for this.  If you find oil on your flywheel or flexplate, use BlueDevil Rear Main Sealer to restore your rear main seal and stop your leak.

 

You can find BlueDevil Rear Main Sealer at any of our partnering local auto parts stores like:

• AutoZone

• Advance Auto Parts

• Bennett Auto Supply

• CarQuest Auto Parts

• NAPA Auto Parts

• O’Reilly Auto Parts

• Pep Boys

• Fast Track

• Bumper to Bumper Auto Parts Specialists

• S&E Quick Lube Distributor

• DYK Automotive

• Fisher Auto Parts stores

• Auto Plus Auto Parts stores

• Hovis Auto & Truck Supply stores

• Salvo Auto Parts

• Advantage Auto Stores

• Genuine Auto Parts stores

• Bond Auto Parts stores

• Tidewater Fleet Supply

• Bumper to Bumper Auto Parts

• Any Part Auto Parts

• Consumer Auto Parts

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leak_repair,jpg – By Welcomia – Licensed by Getty Images – Original Link

Oil Seals Failure and Diagnosis

Often, when parts such as oil seals fail prematurely they are replaced and returned under warranty; however, in most cases the seal itself isn’t the reason the failure has occurred. In this guide, we will take you through the causes and how to avoid premature leaks and failures in the future.

Lip Leakage Diagnosis

If the lip has worn out then this is often caused by the seal not being sufficiently lubricated before installation causing abnormally high temperature, the presence of foreign matter, disproportionate internal pressure or an excessively rough shaft surface. Similarly if when removing a seal, if the lip has hardened and there are visible cracks, you can be sure that this has again been caused by abnormally high temperatures, excessive internal pressure or insufficient lubrication. The cause for the abnormally high wear has occurred due to friction as the amount of lubricant was below the specified level and therefore did not reach the seal lip. Alternatively, insufficient lubrication can come from dry-wear conditions because the vehicle’s oil levels are low. Another sign of this is if the lip wear band is smooth and glossy.

Alternatively, if the lip has softened, then the main cause of this is the lip having the incorrect material required for the application. In order to prevent this from reoccurring make sure the correct seal is sourced for the specific application before installation.

If you notice the lip of the seal has worn unevenly then this is due to cocked seal installation or an excessive shaft offset. As before, both should be checked during installation but crucially before the vehicle is out on the road.

Installation errors tend to be a big factor in automotive parts failing prematurely. This is apparent if you can see that the lip of the seal is scratched, caused by improper assembly, improper handling, an incorrect shaft chamber or the presence of foreign matter entering the seal. The scratches are often caused by being assembled over burrs or other defects in the shaft chamber, the lip coming into contact with sharp metal parts during transit or storage or if the seal was handled with gloves contaminated with metal particles.

As stated improper handling can be a factor in causing a seal to fail prematurely, the tell-tale sign is the seal lip being swollen or soft. The swelling is caused by the lip being soaked in solvents or petrol before installation. Alternatively, if when removing a seal you see the fit trace is disconnected locally then the seal could have been deformed because of an improperly designed assembly jig or a gap in the press-fit occurred due to rough handling.

However, although problems during fitting can contribute to the part failing, other issues may be the key factor. If the lip’s waist (flex area) is broken, then this can be because of improper assembly but can also triggered by excessive internal pressure. Similarly if the lip is turned-under, the lip edge is severely worn and the wear band is concave then this is connected to an incorrect shaft chamber, improper assembly and excessive internal pressure meaning the oil seal area exceeded the maximum pressure it was originally designed for. To prevent this reoccurring, identify the maximum pressure for the seal and check it is compatible with the vehicle. However, if the lip edge is severely worn but there are circumferential grooves on the wear band then the cause is that the shaft finish was rougher than the specified range again this can be prevented by sourcing the correct part for the specific application.

Similarly, if the lip edge is severely worn and there are grooves or indentations on the surface. Foreign matter can affect the seal in many ways whether the cause is due to a shaft or seal that has been contaminated with foreign particles being used or the contaminants were embedded in the seal lip. The cause can be triggered when the seal is assembled in the presence of dirt and/or dust causing the contaminants to become embedded in the sealing lip. In addition, if the seal or the housing was assembled with silicone, the sealant will have contaminated the shaft or seal.

If, when removing a seal the garter spring has become disconnected then this has likely been caused by an incorrect shaft chamber or improper assembly, checking the installation can ensure you and you customers are happy with the finished job.

However, if there isn’t an obvious fault with the oil seal, the cause is often difficult to diagnose, but before you prematurely condemn a good seal first check if the shaft is scratched or the diameter is incorrect, if the shaft rotational direction does not match the helix on the seal, there is excessive shaft offset or runout, the shaft is worn or the seal has been installed incorrectly.

Press-Fit area leakage diagnosis

Below we identify four common causes of premature leaks due to incorrect handling/installation.

If the oil seal is cocked then this can be caused by an improperly sized bore diameter, incorrect shaft chamber or improper assembly jig.

Like with the lip leakage diagnosis if the oil seal is problem free, check if there is a scratched or an improperly sized bore or excessive bore surface roughness. Similarly if the seal OD is damaged or chafed the bore is often the cause. Ensure you check if there is an improper sized bore diameter, incorrect shaft chamber or improper assembly jig before installation.

All the causes mentioned can be avoided if the correct steps are taken when assembling, ordering and fitting a part.

Head over to www.corteco.com/en/products/sealing/ to view our oil seals range. 

This article can also be found online at CAT magazine. 

Oil Leak Causes and How To Fix Them

Yes, it’s easier just to ignore the small puddle of oil forming under your car. Or pretend that the burnt oil smell is not coming from your engine. And is that blue smoke coming out of your tailpipe?

Oil leaks are something you cannot afford to ignore. It doesn’t always take a trained mechanic to figure out what causes engine oil leaks. A little hunting can reveal a lot, just don’t put it off or it can cause damage to your engine.

Is your car leaking oil? Fix it today with No Leak.

Leaks left unchecked can get on rubber hoses or seals and cause them to degrade prematurely. Leaking oil can cause ugly stains on your driveway and are an environmental hazard. And worst of all, engine oil leaks are a fire risk in your engine compartment and can result in catastrophic engine failure at the worst possible time, not that there is a good time for catastrophic engine failure. So fixing oil leaks should be your number one priority.

To check for engine oil leaks keep a close eye on your oil dipstick. If the level drops over time you’re losing oil. While driving, check and see if blue smoke is coming from the tailpipe. Blue smoke means oil might be leaking into the engine itself. After a drive, take a sniff to smell for burning oil. This could mean oil is leaking onto hot components of the engine itself. Lastly, check for the classic oil stains or puddles under the engine compartment, especially after it’s been sitting overnight.

Should you find a puddle under the engine, look a little closer. If the liquid is red it’s probably transmission fluid. If the liquid is green or orange and has a sweet smell, coolant is the culprit. Brown fluid will indicate an engine oil leak.

So what causes engine oil leaks?

We’re glad you asked. The vast majority of leaks are due to degraded engine gaskets, oil pan leaks, oil seals or bad connections. Crawl under the car and check the oil pan seals. While you’re there also check the oil pan drain plug. Next check the timing cover seal and the valve cover gaskets. Problems here can require extensive repairs that are not cheap. Don’t panic! You can always try fixing oil leaks yourself first. It’s not hard. Here are a few options.

Oil Leak Repairs At Home

The most cost-effective and easiest place to start fixing oil leaks yourself is by using a stop leak additive such as No Leak Engine Oil Stop Leak. Once No Leak is inside your vehicle, No Leak softens and conditions rubber seals to stop and prevent automotive leaks safely. It’s best used when engine oil leaks are first detected but is still effective on leaks that have been there awhile.

The next solution is to grab a torque wrench and check for loose bolts starting with the oil pan. Bolts can loosen over time. When the oil pan seems snug, move to the timing belt cover then the valve covers. Just note that each car model requires you to tighten bolts in a specific pattern and to a certain tolerance. Most auto parts stores can provide you with these specifications.

A leak of any kind should be addressed immediately, but an engine oil leak even more so. Knowing what causes engine oil leaks will help you know where to look and how to start fixing it yourself. Don’t ignore it, or hope it fixes itself. Be proactive. Protect and preserve your vehicle’s performance so you can keep it on the road where it’s meant to be.