Export thread

I have an 18 hp Vanguard 350777 on my Simplicity Broadmoor. Oil is leaking from the back of the engine and down onto the deck. Where should I look first, and is this common on these? 366 hours. Many thanks -

Upon further inspection, it may be coming from under the fill tube?

You will have a O ring on the bottom of the dip stick tube.... That's bad or you have too much oil in the engine....

Easy easy fix .........

Let us know Mon Ami ~!~!

Depending upon which model Vanguard you have there will either be a grommet under a flange on the dip stick tube or the tube will have an O ring or two.
They get flattened &/or go hard over time, replace them.

If it's leaking close or by the oil filter this may be your issue 807689 that's the part number and it's a part that is common to leak oil filter adator gasket.

bertsmobile1 said:

Depending upon which model Vanguard you have there will either be a grommet under a flange on the dip stick tube or the tube will have an O ring or two.
They get flattened &/or go hard over time, replace them.

Click to expand...

Do I have to drain the oil before removing the bolt at the bottom of the dip stick tube? May try to tackle this tomorrow.

Luffydog said:

If it's leaking close or by the oil filter this may be your issue 807689 that's the part number and it's a part that is common to leak oil filter adator gasket.

Click to expand...

I will check to see if this is leaking and then running across to the other side of the unit.

bk10s said:

Do I have to drain the oil before removing the bolt at the bottom of the dip stick tube? May try to tackle this tomorrow.

Click to expand...

No the oil level is below the crankcase seam just be careful you don't drop rubbish into it.

Replaced the O ring at the bottom of the filler tube with a match from the hardware store. Dealer only will sell the entire filler tube. However, I may have over-tightened the lower bolt and cracked the tube. Now we will wait and see. I ran it for about 10 minutes and watched. No leak. The tractor sits at a small angle to the left in the garage. It never leaks while it is running on level ground. Fingers crossed!

Bad News. Still leaking. But the area around the dipstick tube looks great! It seems like the oil is flowing out from right under the motor mount closest to the dipstick tube. GRRRRRR!

Still searching.....Why would air be coming out of both valve covers?

bk10s said:

Replaced the O ring at the bottom of the filler tube with a match from the hardware store. Dealer only will sell the entire filler tube. However, I may have over-tightened the lower bolt and cracked the tube. Now we will wait and see. I ran it for about 10 minutes and watched. No leak. The tractor sits at a small angle to the left in the garage. It never leaks while it is running on level ground. Fingers crossed!

Click to expand...

I do hope it was an oil proof Byutyl rubber one and not a neoprene one for water.

Nitrile O-rings are another great choice, also Chem resistant including fuel/oil and withstand higher temps the Byutyl.

Fwiw: Old dead thread but this may help someone?
The Dip stick tube O-ring on my neighbors old 80's Vanguard twin started leaking bad because I removed the top tube bolt to remove its engine cover recently for repairs.
I didn't remove the tube just the top bolt but clearly I disturbed his lower seal enough to leak bad after reassembling. Grrr!

Like many engines I see, his cooling fins were just packed with grass/dirt so it overheated (imagine that?).
Since heat expands chit bigtime it spit the valve guide out of his head & bent both aluminum exhaust push rods.
Very common issue with air cooled engines where owners fail to remove their engine cover & really clean the fins out thoroughly every few yrs, more often on machines used daily. The cooling fan draws air in to cool them right along with dirt, grass, leaves, trash etc.. therefore they all need a good cleaning. Just doing this very simple task adds many yrs of life to your engine! Never spray water on a hot engine NEVER!
An air compressor (I prefer) or just picking/scraping the dirt/debris out does the trick. If hosing it off always cover coils & carb with plastic bags first.

Also if the engine has an external oil cooler (small radiator looking part with 2 rubber hoses). Understand those rubber oil hoses leading to them will become very brittle eventually & they split/crumble. That allows your engine to lose oil very rapidly while mowing destroying an engine within minutes before its even noticed.
Inspect their hoses regularly, if hard, leaking or cracked then immediately replace both oil cooler lines with a good grade high pressure hose before its too late. Sadly not buying about 1 foot of hose (2 lines about 6" long on most) has sent many outstanding engines to the scrap man. Not just Briggs either, goes for any with an external oil cooler!
Most small engines oil pumps have less than 10psi pressure but still I only buy a reinforced hose for this application, know what I nean Vern?
Hope this helps save a few engines!

What are the rest of the numbers for your engine?

Check out Parts Tree for your exact engine series

I think you are mistaking the air you feel that is coming away from under the top cover. The upper shroud cover directs air over the entire motor to cool, especially the cylinders. It's good to remove the top cover at the end of every season and clean inside, dirt and grass clippings get caught in the cooling fins and it will slowly damage the motor.

As for the oil leak, you need to clean everything really well to determine exactly where it is coming from. Oil travels and migrates with heat. Find the source after cleaning well.

Sump base gaskets are not uncommon to leak along with the bottom of the valve covers. If it has an oil cooler, that can be suspect as well.

Very old post....But the O-ring is Briggs PN 691032.

And UV dye helps a lot on hard to trace leaks.

StarTech said:

Very old post....But the O-ring is Briggs PN 691032.

And UV dye helps a lot on hard to trace leaks.

Click to expand...

Greetings Startech,... We use UV Dye commonly in searching for leaks in Air Conditioning, & Refrigeration, that has no ill effect upon the Compressor, Thermal Expansion valves, etc.

Is this "UV Dye", & the UV Light, that We use in HVAC similar what You are speaking of?

Hello Husqvarna rider,

A/C typically breaks down quickly with engine oil heat, but you can try it.

You can usually get oil specific dye at most automotive parts stores. You will need a UV light and glasses to see details. I usually check oil leaks with minimal lighting or at night for best results.

I work on a lot of automotive systems along with Farm & Ranch and small engine equipment. Using oil dye eliminates a lot of guess work. "The dye don't lie" is a phrase I use often.

Auto Doc's said:

Hello Husqvarna rider,

A/C typically breaks down quickly with engine oil heat, but you can try it.

You can usually get oil specific dye at most automotive parts stores. You will need a UV light and glasses to see details. I usually check oil leaks with minimal lighting or at night for best results.

I work on a lot of automotive systems along with Farm & Ranch and small engine equipment. Using oil dye eliminates a lot of guess work. "The dye don't lie" is a phrase I use often.

Click to expand...

Thank You Auto Doc!
I was thinking that if I already had the Dye/Light etc. that it would save some $$$$. The Dye that we use will work up to 700 PSI, & Temps up to 400 degrees F., as well as work with more than 30 refrigerants, if I remember correctly. And it can be used with R134A that is commonly found in Automotive Air Conditioning.

But, ... I had a "nagging thought" that the motor oil could cause issues. So, there is a UV Dye specific for motor oil?