Mower Crankshaft Oil Seal Continues to Leak
Whenever you're dealing with any kind of internal combustion engine, you never want to see oil in places that it shouldn't be. Having a lawn mower leaking oil onto the deck is one of those unfortunate situations. This kind of happened to me after I pushed my Honda push mower into a low-hanging branch and knocked the oil cap off. Oil was shooting everywhere and sure was a pain to clean. But, there are all kinds of reasons why you might have a lawn mower leaking oil onto its deck. Hopefully, your problem won't be as messy as mine was.
Why is My Lawn Mower Leaking Oil onto the Deck? (The Short Answer)
If you've got a lawn mower leaking oil onto the deck, it's probably coming from the crankcase or oil reservoir. This usually occurs because of a bad seal or because the oil reservoir was overfilled. To tackle this issue, you'll need to clean off the oil, identify where it leaked from, and go from there.
Possible Causes of a Lawn Mower that's Leaking Oil Onto the Deck
Oil travels all around a lawn mower's engine and lubricates all its parts as it goes. While the engine runs, the oil will warm up, get thinner, and move more easily. As this is happening, seals expand in size, and the crankcase creates a vacuum that draws oil in. When there is a malfunctioning part, you could end up with some oil leaks. I'll go through the most common causes of oil dripping onto a lawn mower's deck below.
Faulty Seals
One of the most typical causes of oil leaks is seals or gaskets that have gone bad. Because they're constantly heating up and cooling, they wear out over time. If you're dealing with oil dripping onto the mower's deck, it is most likely coming from one of the seals that helps carry oil around the engine. No matter whether you've got a Toro, Craftsman, or any other brand mower, there are a number of different seals and gaskets so it's best to identify the source of the leak and go from there.
Overfilled Oil
Putting too much oil in your mower is easier to do than you might think. When the oil reservoir is overfilled, you can experience oil leaks from the reservoir cap all the way through to the exhaust. Though you don't want leaks anywhere, you certainly don't want oil coming out of your lawn mower's exhaust. To avoid overfilling oil, be sure to check the dipstick regularly as you go and just add a little bit at a time.
Tipping Lawn Mower Incorrectly
Flipping your lawn mower onto its side with the air filter and carburetor facing down is something you should never do. Gravity works against you when you tip your mower the wrong way and draws oil through the engine, soaking your air filter and spark plug. If this happens, you could end up with excess oil dripping out onto the deck of your mower.
Cracked Breather Tube
You can usually find the breather tube on your lawn mower near the valves and behind the muffler. This tube has a small reed in it that collects oil so that it can directly lubricate the piston. If you notice that the origin of your oil leak is near there, there's a good chance you have a cracked breather tube. This is especially common on Briggs & Stratton mowers.
How to Fix a Lawn Mower Leaking Oil onto the Deck
To go about plugging up whatever part is leaking on your lawn mower, you'll want to take a systematic approach to first diagnose the problem and then get the faulty part fixed. I'll go into more detail and describe the steps you can follow to get your mower repaired and ready to go again.
1. Locate the Oil Leak
The very first thing to do if you have a lawn mower leaking oil onto its deck is to figure out where it came from. In order to do this, start by cleaning off all of the spilled oil. After soaking up the oil on the deck, give the whole engine block a good scrub and remove all the dirt and debris that may be on it. This will help identify the oil leak.
Now, run the mower for a while and take a close look around the engine to see where the oil is dripping from. Be sure to run your mower long enough to warm up completely when you do this. It's important for the oil to get hot since the oil will be thinner and able to move (or in this case, leak) more freely.
2. Drain Oil
Once you have found the source of your pesky leak, you'll need to drain the oil out of your lawn mower. Some lawn mowers have a drain plug which will make things super easy, but sometimes you need to tip the mower to drain directly from the reservoir.
In both cases, be sure to remove the spark plug hood and cable before getting started. Then, tilt the mower with the air filter and carburetor facing up (if possible) and let the oil spill into a collection pan or jug.
As the oil drains, you may notice some dripping out of the exhaust as well. Don't worry, all you need to do is wipe it off with a rag and any residue will burn off when you run your mower next.
3. Replace Faulty Parts
The intricacies of replacing the parts responsible for your leak can either be quite simple, or relatively involved.
Start by checking your air filter again to see if the oil leaked from tilting your mower incorrectly. Then, double or triple-check your dipstick to be sure you had the correct amount of oil in the reservoir. It's a good idea to make sure these aren't the culprits before you start taking engine parts off.
If you have a bad gasket or seal, you'll need to remove and disassemble whatever parts are necessary to assess and replace the seal. If you suspect your breather tube is cracked, you need to remove the muffler and inspect it.
If the leak originated somewhere in the engine block that seems foreign to you, it might be best to consult your local mechanic. Disassembling engine parts can be tricky and lead to a major headache if you don't have experience wrenching around with them.
4. Add New Oil
After you have found the source of the oil leak and stopped it, just be sure to add some new oil. Be careful when you're doing this so that your mower only gets as much oil as it needs.
I like to add a little bit at a time and check my dipstick as I go. Once the oil is added you're ready to start your mower up and get back into action.
What About Riding Mowers Leaking Oil Onto the Deck?
If you've got a riding lawn mower leaking oil onto the deck, you could very well be dealing with the same issues as you would with a push mower. Though you won't be as prone to tipping your riding mower on its side (unless you're a contender for World's Strongest Man), you definitely could have added too much oil by accident or run into some failing gaskets.
One particularly important seal on a riding mower is the head gasket. If you have a blown head gasket, your mower won't be able to produce as much power and you might notice it going more slowly than usual or struggling on hills. Unfortunately, if this happens, you'll need to pull the engine out of the mower and split it open.
Although this doesn't happen as often, it's an issue to be aware of with riding mowers. Whether you have a riding or push mower, it's a good idea to follow the steps listed in the section above to remedy the oil leak.
Fix This Right Away or There Could Be Trouble
Allowing your lawn mower to leak oil onto the deck without taking action could result in:
- Damage to the engine
- Your lawn mower blowing white or bluish smoke
- Contamination of the air filter
- Fouled spark plugs
- Clogged mower muffler
- Worse fuel economy
- Carburetor problems
Source: https://lawnmowerguru.com/lawn-mower-leaking-oil-onto-deck/
0 Response to "Mower Crankshaft Oil Seal Continues to Leak"
Post a Comment