Briggs Vanguard 23hp Leaking Oil through Breather Tube

SnapperOwner

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  • / Briggs Vanguard 23hp Leaking Oil through Breather Tube
Snapper YT2350 YT400 Series 50" Lawn Tractor (aka Riding Mower)
B&S Vanguard V-Twin 23hp
Model 386777
Type 0111-E1
Code 0705241
Part 2690752
Purchased February 2009
545 hours of use

Mow Two Acres in Ohio (grass and mole hills), April-October. We live in the county, nowhere near a town. Hometown USA. Dealer is a one-man shop. Send away or drive three hours for parts.

Done a lot of work over the past three months and have the mower starting again. New (all Briggs, using Parts List for this engine): carb, wiring harness to fuel solenoid (which is built into the new carb), fuel pump, fuel and vacuum lines, fuel + oil + air filters, PTO switch, dipstick tube, breather hose, o-ring seal on breather assembly, and gaskets on valve covers and carb. Valves were .004 when we checked. Compression readings were 130 and 120.

++++++++++++++++++++++

Thought we had it back and running again. First time using it since all the new stuff listed above was done. Starts great, with no smoke or sputtering. Managed to cut the grass for 25 minutes with no problems or miss, when it shot a small puff of white smoke out of the side from under the hood (not exhaust). Did one more circle, to see if it was just a one-time issue (have done a LOT of work on it), when it shot a large plume of white smoke from the same place. No subsequent loss of power or surge/miss, but I only drove about twenty feet to the garage and turned it off. Engine started with the soil stick at 1/2-way up the hatch (middle) and now is sitting right at the bottom of the hatch (Add). No smell of gas from the oil.

Here's what I found under the hood.


(All left/right mentions are me looking at the air cleaner on the front of the engine, standing in front of the mower.)

1) The mess on the back left side by the oil filter and cooler is a mystery to me (photos 1 & 5). The hoses look fine but aren't soft/flexible at all. Supposed to be pre-formed, hard tubes?

2) Photos 2 + 3+ 4 show the main leak. Oil was dripping from the bottom of the air-filter cover, and that's what soaked/puddled the tin to both sides. 1-2 Tablespoons of oil pooled inside the bottom of the cover when we removed it, filter and pre-filter soaked on the bottom near the puddle but not all over. Oil had backflowed through the breather hose (which is new and definitely not clogged) and covered a lot of the inside of the air-filter cover. Looks like there is oil in the front of the carb, too. Not dripping, but sitting near the front, like the breather tube tried to get out that way. The filter-cover-to-carb gasket is soaked in oil now. Just replaced the valve gasket covers, twice on the right-hand one.

Heeeeelp! I'm just a homeowner who's been learning a lot over the last three months. Please don't assume I know much more than what I've shared. I really need help here. Seems a shame to have come this far and be done in by an oil leak.

Thanks for your time, in advance.


October 11, 2021 (2)b.jpg Oil Leaks (12)b.jpg Oil Leaks (1)b.jpg Oil Leaks (3)b.jpg Oil Leaks (8)b.jpg
 

Rivets

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  • / Briggs Vanguard 23hp Leaking Oil through Breather Tube
From the pics you posted and your description, I would be checking for a blown head gasket.
 

bertsmobile1

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  • / Briggs Vanguard 23hp Leaking Oil through Breather Tube
What he said
It was most likely the cause of the original problems
The head gaskets are weak on Inteks on purpose so they blow to save the rods & crank
 

hlw49

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  • / Briggs Vanguard 23hp Leaking Oil through Breather Tube
Not an Intek it is a Vanguard. Blown Head gasket or a crankcase breather valve. Pull the crank case breather cover off the #2 cylinder and check to see if the reed valve is broken.
 

ILENGINE

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  • / Briggs Vanguard 23hp Leaking Oil through Breather Tube
I think I would pull the blower housing off and take a look around. The pictures with the oil filter appear to have oil running down the side of the block. Possible top seal leaking.
 

SnapperOwner

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  • / Briggs Vanguard 23hp Leaking Oil through Breather Tube
I REALLY appreciate all the replies! After nearly three months of my daughter "mowing" the two acres with a weedeater and me watching videos/reading forum threads, I'd like to think we're getting close here. I'm not an expert (not even a novice), but I only have a week or so before I need to winterize this puppy. I'd hate to put it away until spring without resolving this.

ILENGINE -- I've had the housing off so many times that I'm surprised the screws still work (smile). What would I be looking for now? What is the "top seal"? My Parts List shows five seals on the Crankshaft page: oil seal (magneto side), oil seal (PTO side), O Ring Seal (oil pump), Oil Gallery O-Ring (crankcase cover/sump or cylinder assembly), and a governor shaft seal.
 

SnapperOwner

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  • / Briggs Vanguard 23hp Leaking Oil through Breather Tube
Thanks, rivets and bertsmobile1! I'm a bit stumped about the blown-head-gasket idea. (I only know what I've seen in the umpteen videos and blog/forum reading I've done, so please don't think I'm saying I know more than you. Guarantee that I don't! I just want to make sure I give what info I have.) Even though leaks here and there, no oil usage registered on dipstick until this thing leaked yesterday, and the oil that's missing could probably be accounted for by what was dripping and pooling everywhere. The smoke that I mentioned came out of the right-hand side of the hood; it never seems to come out the left side. Both times, it was one cloud, as described. Ran smoke-free the rest of the time.

Just thought of something else that happened about two months ago. After running out and finding another person out there going crazy with channel locks on the carb mixture screws (wildly screwing both back and forth in sweeping motions, with the machine backfiring all over the place), we turned it off and pushed the mower into the garage (without waiting the minute). After making the person leave, we started it up again. It made this really loud POP (like a bang) and a huge cloud of smoke surrounded the mower. We turned it off, let it cool down, and started it again. Has never done that again, and starts like a champ. Have only put about an hour TOTAL in trying to mow, as we were testing things after every replacement.

If I have to order the gasket kit, it'll take a while to get in. IF I have to do this, can someone please tell me what supplies you use to clean the piston head and gasket area? The videos I've seen just say "gotta clean this up, so I'll be back". I really don't WANT to have to change the head gaskets, but I'm not AFRAID to if I have to.
 

SnapperOwner

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  • / Briggs Vanguard 23hp Leaking Oil through Breather Tube
Not an Intek it is a Vanguard. Blown Head gasket or a crankcase breather valve. Pull the crank case breather cover off the #2 cylinder and check to see if the reed valve is broken.
Okay, I can do that. I'll come back once we've had a look. Hope "broken" is easy to assess.
 

SnapperOwner

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  • / Briggs Vanguard 23hp Leaking Oil through Breather Tube
What should I do about that thin layer of oil in the carb? After three complete teardowns/cleans of the original carb, I decided to chunk out the $300 for a replacement carb so that I could take that out of the equation. If I have to go back to cleaning in there, I think I'll be depressed (smile). But I want to do the right thing.
 

SnapperOwner

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  • / Briggs Vanguard 23hp Leaking Oil through Breather Tube
Just pulled the plugs. The spark plugs were brand new when we cranked this up for the 25-minute mow. Plugs are exact B&S part called for in manual. Bit of oily feeling to the tips, but not sitting in oil. Black tips, but they started silver two days ago.

Removed the #2 valve cover and found the rest of the "missing" oil. It was really full. Going to check the reed valve now.

Spark Plugs (4).JPG Spark Plugs (5).JPG
 
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