Is it worthwhile to fix a rear main seal leak

Whether fixing a rear main seal leak is worth it depends on several factors, such as the extent of the leak, the age and condition of the vehicle, and the cost of the repair. A rear main seal leak can be a significant issue as it can allow engine oil to leak, which can result in reduced oil levels and potential engine damage. However, if the leak is minor and the vehicle is in good condition, it may not be necessary to fix it immediately. Ultimately, the decision of whether to fix a rear main seal leak should be based on a careful consideration of the factors mentioned above and a professional mechanic’s assessment of the issue.

Can I drive with a leaking rear main seal?

It’s not recommended to drive with a rear main seal leak as it can lead to reduced engine oil levels and potentially cause significant engine damage. Engine oil provides lubrication and cooling for the engine’s internal components. A significant loss of oil can result in friction and overheating, which can cause serious damage to the engine. If you’re driving a vehicle with a rear main seal leak, it’s important to monitor the oil level regularly and top it up as needed to prevent the engine from running low on oil. You must remember that this is only a temporary solution and that the leak should still be repaired as soon as possible.

How can the rear main seal be checked?

To check for a rear main seal leak, You must check the following points. 1- Check for oil on the ground 2- Clean the area around the rear of the engine 3- Check the oil level 4- Look for oil seepage

Can a rear main seal leak damage transmission?

Yes, a rear main seal leak can potentially damage the transmission. If engine oil leaks from the rear main seal, it can contaminate the clutch and transmission fluid, leading to slipping and other issues with the transmission. Over time, the oil can cause damage to the transmission’s internal components, leading to a need for costly repairs or even replacement of the transmission.

What causes seal failure the most frequently?

The most common cause of seal failure is age and wear. Over time, seals can become brittle and crack, leading to leaks. This is especially true for the rear main seals, which are subject to high levels of stress and pressure as the crankshaft rotates.

Cat C15 engine Rebuild [DIY & Professional Install]

Scott Automotive

Even with regular maintenance, chances are that your diesel engine will eventually succumb to wear and tear and will need to be rebuilt. The good news is that there are whole kits and overhaul options available to make it even easier to rebuild your Cat C15 engine.

It typically costs anywhere from $20,000 to $40,000+ to rebuild a Cat C15 engine. The final price may be higher or lower depending on the year, engine specifications, the type of rebuild kit, and labor costs for your geographic location.

Engine Rebuild Versus Engine Overhaul

Often, the terms “rebuild” and “overhaul” are used interchangeably when it comes to trucks and heavy equipment. The processes are quite similar, and in fact, an engine overhaul typically involves taking the engine apart and reassembling it.

Some people differentiate between the two terms by referring to an in-frame kit as an overhaul and an out-of-frame kit as a rebuild.

Cat Engine Overhaul Cost Estimate

Minimum Cost Estimate	$15,000-$20,000
Maximum Cost Estimate	$40,000-$50,000
Average Cost Estimate	$25,000-$35,000

The amount of work done and the cost are important factors for deciding what’s best for you and your truck. An engine overhaul is almost always a more economical option when compared to replacing the engine.

According to Foley CAT, An engine overhaul is a service that will return your engine to like-new condition.

Service technicians will remove the engine, disassemble it completely, inspect and clean all the parts and components, make any necessary repairs, and then do various performance tests.

Many service providers also sell overhaul kits as a lower cost alternative for owners who have the resources and know-how to do the engine work themselves.

Overhaul kits contain all the various parts and replacement components that you would get with an engine overhaul service.

Engine overhauls come in various levels that include different services and repairs. One consideration is to go with a certified engine overhaul.

Certified overhauls use factory parts and are performed at service centers that CAT has certified for workmanship, so the factory will back the overhaul.

Engine Rebuild/Overhaul Options

Cat engine rebuild options come in several different levels. The overhaul kits contain different levels of service and maintenance, with the more inclusive packages being more expensive.

Engine Overhaul Kit Cost Ranges

Price Comparison	Kit Level	Kit Type	Cost Estimate
Least Expensive	Bronze Level	In-Frame	$2,000-$3,000
Low-End Cost	Silver Level	In-Frame	$4,000-$6,000
Mid-Range Cost	Gold Level	In-Frame	$5,000-$7,000
High-End Cost	Platinum Level	Out-of-Frame	$9,000 - $13,000
Most Expensive	Titanium Level	Out-of-Frame	$13,000 - $15,000+

One of the benefits to choosing a Cat certified kit is that it will include a factory-backed warranty. Most of the options come with a 12-month warranty on the parts, labor, and certain types of damage.

The factory warranty also has no limit on the number of miles during the 12-month period. After the initial warranty expires, they offer extended coverage options for up to four years without mileage or hour limitations.

Depending on your engine and your specific situation, the warranty option may be a good investment.

Bronze Overhaul Kit

The CAT bronze kit includes:

Low-cost, basic repair option
No core charges
Main, rod and thrust bearings
Seals and gaskets, retainers, plugs, all necessary hardware
Cat oil filter, fuel filter, exhaust sleeves, studs, thermostats

Silver Overhaul Kit

The CAT silver kit includes:

Includes all parts from bronze kit, plus:
Six pistons, rings, pins, retainers
Basic, in-frame overhaul
No core charges

Gold Overhaul Kit

The CAT gold kit is the most cost-effective extension of the engine’s life, and it includes:

All core components from the bronze kit, plus:
Six Reman piston packs (pre-assembled to save on labor charge)
Basic, in-frame overhaul

Platinum Overhaul Kit

The CAT platinum kit replaces the need for block machining, and it includes:

All parts from the gold kit, plus:
Bare block
Reman HEUI pump
Six Reman injectors
Reman oil pup
Reman cylinder head
IAP sensor
Complete out-of-frame overhaul

The platinum level overhaul also typically includes the most extensive warranty, such as a four year unlimited mileage warranty. Other overhauls generally will include a 12-month warranty.

Titanium Overhaul Kit (Not available for C15 at this time)

The CAT titanium level kit includes:

All parts from the bronze kit, plus:
Reman long block (includes factory-installed HEUI pump, oil pump, oil cooler)
Six Reman injectors
IAP sensor
Complete out-of-frame overhaul

In-Frame Versus Out-of-Frame Rebuild

There are two types of engine overhauls: in-frame and out-of-frame rebuilds. They are slightly different in what work is included and how much they cost. An out-of-frame rebuild is typically more expensive than an in-frame.

An in-frame rebuild is usually for engines that have over 20,000 hours, and the engine remains mounted for the service. For an out-of-frame rebuild, the engine is removed and disassembled then rebuilt.

If the engine has suffered block damage or engine crank damage, it will most likely require an out-of-frame rebuild.

Let’s take a look at what’s typically included in each type of kit.

In-Frame Rebuild

Liners, pistons, rings
Main bearings
Connecting rod bearings
Front cover gasket
Exhaust gaskets
Turbo seals
Head pressure test (replace if needed)
Injector test
Air cleaners

Out-of-Frame Rebuild

Liners, pistons, rings
Main bearings
Connecting rod bearings
Front cover gasket
Exhaust gaskets
Turbo seals
Head pressure test (replace if needed)
Injector test
Air cleaners
Front and rear structure gaskets
Block
Camshaft (replace if needed)

To help clarify the difference between an overhaul and an engine rebuild, many professionals use the in-frame versus out-of-frame designation to differentiate between the two.

An in-frame kit is more accurately described as an engine overhaul, while an out-of-frame kit is more accurately described as a rebuild.

One of the main benefits of an out-of-frame rebuild is that it will result in more parts and components being replaced at the same time.

So, even if those parts aren’t at the end of their life just yet, you’ll know that the engine has even wear and you won’t have to worry about one component failing unexpectedly.

How Many Miles Can a Cat C15 Last?

Your Cat C15 is a lean, mean driving machine that is built to last. The life expectancy is a whopping one million miles, so long as you take care of the engine and keep up with scheduled maintenance.

Many drivers keep the truck for even longer, with at least one long time owner still going strong after 3-million miles.

However, eventually you will need to rebuild the engine to keep your Cat C15 running the same way it did when you first got behind the wheel.

Signs That It’s Time to Rebuild Your Cat C15

Even a tough, well-made engine will eventually need to be rebuilt. Reduced performance and other issues may indicate that it’s time for an overhaul.

Here are some symptoms to be aware of to help you know that it may be getting close to the time for a rebuild:

Reduced fuel efficiency
Knocking sound
Crankcase pressure
Excessive oil consumption
Excessive smoke
Oil looks like sludge
Compression issues

If you begin to notice these types of issues, it’s time to do some further testing and have your engine checked out by a professional.

You can check the oil for contaminants, high metal concentration, or unfiltered air in the system. You can look for excessive blowby, which may be caused by wear and tear on the piston and ring.

Re-Ring Kits

Another option is a re-ring kit, which is the smallest overhaul kit available. It’s only good for engines that still have usable pistons and if the other engine components are in relatively good condition.

For some engines, it may be a better option to go with an overhaul or rebuild, but this is an option for a quick tune-up.

A re-ring kit for a Cat C15 typically costs between $1,200-$1,700.

Re-ring kits are good for engines that just need a refresh. They usually contain cylinder liners, piston rings, connecting rod bearings, main bearings, thrust washers, a cylinder head gasket set, and an oil pan gasket set.

The Bottom Line

Rebuilding or overhauling the engine on your Cat C15 is a worthy investment because of the long life expectancy of the engine.

It will improve your engine’s performance and repair any looming issues before they become severe enough to take you off the road. Another benefit is the warranty that the work will carry and the potential improvement for your resale value.

However, an engine rebuild is a hefty investment, so you’ll need to consider the cost and benefits for your situation. You’ll also need to think about how you’ll finance such a large investment and take those fees and interest into consideration.

However, there are companies out there which provide financing specifically for engine overhauls, which may be something worth looking into.

If you want to extend the life of your Cat C15 engine and improve your overall performance, then a rebuild may be the best option for you.

Scott

Scott Brown is an experienced and highly skilled former ASE Master Technician with a specialty in diesel engine work. With over 15 years in the automotive industry, scott has developed a deep understanding of the engine rebuild process. He is constantly keeping up with the latest advancements in diesel engine technology.