Missing O-Ring?

cruzenmike · Feb 15, 2018

I have an 18hp Vanguard, model, make, code 356777-0115-E1. I was running into an issue with oil getting on my mower frame at the base of the engine without being able to identify the source. I removed the dipstick tube and found a partially flattened o-ring which I have replaced. Now the question is, am I missing another o-ring? One parts diagram shows that the dipstick tube has an o-ring at the top for the dipstick and one at the bottom where the tube enters the block (the one I replaced). A second diagram shows an o-ring that possibly sits in the block (oil gallery). When I removed the dipstick tube there was nothing sitting beneath it in the block. Am I missing something? Here are links to the two diagrams:

https://polr.partstree.com/v1/iplim...wdGlvbnMiO2E6MTp7czo1OiJ3aWR0aCI7aToxMDAwO319

- item 524 is what I replaced.

https://polr.partstree.com/v1/iplim...wdGlvbnMiO2E6MTp7czo1OiJ3aWR0aCI7aToxMDAwO319

- Part 439 is the one I don't know if I need.

I appreciate your help.

Mike

cpurvis · Feb 15, 2018

What about p/n 842? That looks to me like the top o-ring. Along with 524, that looks like the pair of o-rings on the dipstick tube.

Boobala · Feb 16, 2018

I recently replaced those O-Rings on my B & S 21 HP, I also could NOT see any other O-ring in the tube's bore, I still have a light oil film in the area but it's of minor significance to me, I chalk it up to fumes, I worry more about CLEAN and FULL oil or smoke from the exhaust, looking at the parts breakdown, it appears it MIGHT be in between the block and the sump ..??? Have to read the O/H Manual on RE-assembly . ..:confused2: ..

Found in Vanguard O/H manual # 272144 .. Pg. 147

but found no other mention ??

ILENGINE · Feb 16, 2018

Boo, I looked at the diagram yesterday, and wasn't thinking that number you referenced would be the O ring that sits inside of the sump gasket for the oil passage from the oil pump to feed oil to the top bearings in the engine.

Boobala · Feb 16, 2018

ILENGINE said:
Boo, I looked at the diagram yesterday, and wasn't thinking that number you referenced would be the O ring that sits inside of the sump gasket for the oil passage from the oil pump to feed oil to the top bearings in the engine.

I could find nothing mentioned in the O/H manual(s) mentioning removal or replacement of that other O-ring, beats hell outa me !!

cruzenmike · Feb 16, 2018

It is truly puzzling. The o-ring at the top of the tube is fine and have never found any oil on the tube. The bottom o-ring was not completely in the groove on the tube and was slightly flattened, so I replaced that one. I talked to my exmark dealer and a place that works on Briggs and they are both puzzled by it. Last year I paid to have the bottom o-ring replaced and have not seen the oil stop puddling at the bottom of the engine. Thankfully the oil in the engine stays clean and I do not notice any significant loss requiring a refill. I am thinking of selling so I would like to get this issue resolved once and for all. Thanks for your help.

bertsmobile1 · Feb 16, 2018

Are you filling the engine with the correct amount of oil ?
Common mistake is not to screw the dip stick in when measuring the oil level.
This has the oil level in the sump at or higher than the top of the dip stick tube casting so it will always leak.
The dip stick tube is HDPE which is a bad choice of materials as it a thermo plastic deforms when it gets hot so is not stiff enough where the O ring sits to maintain an oil tight seal.
Have you checked the governor shaft ?
On commercial mowers the shaft floggs the hole oval due to the number of operating hours.

cruzenmike · Feb 16, 2018

bertsmobile1 said:
Are you filling the engine with the correct amount of oil ?
Common mistake is not to screw the dip stick in when measuring the oil level.
This has the oil level in the sump at or higher than the top of the dip stick tube casting so it will always leak.
The dip stick tube is HDPE which is a bad choice of materials as it a thermo plastic deforms when it gets hot so is not stiff enough where the O ring sits to maintain an oil tight seal.
Have you checked the governor shaft ?
On commercial mowers the shaft floggs the hole oval due to the number of operating hours.

I always check the oil with the dipstick screwed in. The seals around the governor shaft were replaced last year by the dealer. I considered the issue of the plastic tube changing due to heat over the years. This machine has been used privately with no more than 2 hours of run time on any given cut. Besides, the leak appears only to be on that side. The front end if the engine where the governor shaft comes out has no oil showing on the frame.

bertsmobile1 · Feb 16, 2018

New dip stick tubes are not all that expensive and being given the old one 'cause it used to weep a bit" will make a potential owner believe your were fastidious about maintenance.

cruzenmike · Feb 16, 2018

bertsmobile1 said:
New dip stick tubes are not all that expensive and being given the old one 'cause it used to weep a bit" will make a potential owner believe your were fastidious about maintenance.

I attempted to order a new tube and the replacement part from Briggs doesn't match what I have on mine. The dipstick tube shown on the parts diagram only secures at the top whereas mine has two holes in which it is secured to the crankcase as well. I guess if I can find that part I will replace the whole thing as well.

Missing O-Ring?

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