briggs oil leak

Reply

  #1  
Old 11-14-12, 03:37 PM
sgull's Avatar
Member
Thread Starter
Join Date: Nov 2007
Location: AK
Posts: 2,586
briggs oil leak

The Briggs & Stratton engine on my pressure washer has been leaking oil through where the "governor crank shaft" is installed through the engine housing. Engine model is 150212, type 0122-E9. I disassembled the engine enough to access the source of this leak, and here's a photo of the governor crank shaft part to which I refer. http://i207.photobucket.com/albums/b...ps3117e348.jpg
In the photo, the engine is on its side and the right side of the photo is the top of the engine. The governor shaft is projecting through the top of the engine there, and on the left side you can see the fuzzy picture of a philips screwdriver shaft I'm using to point to the other end of the part, which has a "paddle" connected as part of the shaft which contacts the "governor cup" during operation.
I have the illustrated parts list for the engine, in which the governor crank shaft is identified as part number 692547. It is baffling to me why/how oil is leaking out the opening for the shaft, as the opening seems to be a pressed-in brass-type sleeve (bushing?) through which the shaft is installed. There is no o-ring or other type part that you'd think might be installed there as a seal to prevent any leakage, neither to be seen or indicated in the illustrated parts list.
But for whatever reason, during engine operation oil leaks out of there pretty good, making a mess as it spews up through and onto the control bracket under the gas tank and pools up and trickles down the side of the engine.
Upon examination I can't see any particular wear or scoring inside the brass opening or of the shaft itself, so can't understand why its leaking here or what exactly needs to be done to stop it. Any comments/advice appreciated. thanks
 
Sponsored Links
  #2  
Old 11-14-12, 03:45 PM
cheese's Avatar
Forum Topic Moderator
Join Date: Jul 2001
Location: USA
Posts: 16,815
How much slop is there in the fit of the shaft? If it's blowing out that badly, check the blowby from the breather hose. You may either have a blocked breather or a blown head gasket, either of which would create excessive internal pressure in the crankcase.
 
  #3  
Old 11-14-12, 04:22 PM
sgull's Avatar
Member
Thread Starter
Join Date: Nov 2007
Location: AK
Posts: 2,586
Doesn't seem to be any side-to-side or wiggling type slop in the fit of the shaft at all. Here's a video of me pushing it in and out: MVI_1950_zps15b3e229.mp4 video by sgull1 - Photobucket
It slides easily in and out back and forth but I suppose that's normal. The breather hose is clear, not blocked or kinked. As far as the question of a blown head gasket, the engine and pressure washer seems to operate without any noticeable adversity, and I suppose if the head gasket were blown I should be able to tell, wouldn't I?
 
  #4  
Old 11-14-12, 05:35 PM
cheese's Avatar
Forum Topic Moderator
Join Date: Jul 2001
Location: USA
Posts: 16,815
Usually a blown head gasket on an OHV small engine doesn't give running problems, especially at first. It usually starts with oil consumption. The combustion pressures leak past the blown spot into the chamber where the pushrods go. This pressurizes the crankcase and pushes oil out any places it can go. This normally is out the breather tube and into the carb, so oil ends up pumping into the carb, causing smoke. Usually it will do this sporadically, when the pressures build up enough in the engine, so the smoking isn't continuous... just short periods of time that the engine belches smoke and then goes back to normal. I don't know that I have ever seen a blown head gasket on that model engine, so I don't know what that model is prone to do when it happens.
 
  #5  
Old 11-14-12, 05:50 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 45,088
It's like deja vu. I was at my sisters over the past weekend and her Briggs engine on her generator is doing the exact same thing. A consistent drip from the governor shaft. No noticeable blow-by from the breather. From what you're saying there is no replaceable O ring. Is that possibly a replaceable brass insert ?

On edit: Is the governor shaft submersed in the crankcase oil ?
 

Last edited by PJmax; 11-14-12 at 05:53 PM. Reason: additional question
  #6  
Old 11-14-12, 06:38 PM
sgull's Avatar
Member
Thread Starter
Join Date: Nov 2007
Location: AK
Posts: 2,586
Pjmax,
Nope there is no replaceable O ring, nor is the brass insert replaceable (neither shown in the parts breakdown/diagram/list). My leak would be more described as a spewing seepage (not really a “drip”) up and out of the governor shaft orifice. And no, the governor shaft is not submerged in the crankcase oil.
 
  #7  
Old 11-14-12, 06:53 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 45,088
I was cruising around and reading generic threads about this problem on B & S sites. Some engines have a replaceable O ring. Some have a replaceable sleeve. But most of the leaking problem is blamed on a breather problem Some have also mentioned a head gasket failure but that seems to be rarer.
 
  #8  
Old 11-14-12, 06:54 PM
sgull's Avatar
Member
Thread Starter
Join Date: Nov 2007
Location: AK
Posts: 2,586
I suppose then I should take a look at the head gasket then, assuming I'll see that it's blown, and if so replace it. If it's blown I would think it should be visually obvious? As I mentioned, the breather hose is clear. Unless there is some other way the breather can be "obstructed" other than something clogging up the hose? Any further advice/comment appreciated. thanks
 
  #9  
Old 11-14-12, 07:26 PM
cheese's Avatar
Forum Topic Moderator
Join Date: Jul 2001
Location: USA
Posts: 16,815
The breather valve could have a problem, but I think in my twenty some years of working on small engines, I have only seen two bad breather valves. The head gasket can be quite obvious when you see it if it is totally blown, but if it is barely leaking, it could be harder to see. Look closely at the area between the cylinder wall and the pushrod chamber. This is where it will be blown if it is.
 
  #10  
Old 11-14-12, 10:02 PM
sgull's Avatar
Member
Thread Starter
Join Date: Nov 2007
Location: AK
Posts: 2,586
If there is an actual part called the breather valve for this engine, it seems to be not included in the parts diagram breakdown list. There's the breather tube, but not an actual breather valve, that I can find anyway.
 
  #11  
Old 11-15-12, 02:18 AM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 45,088
It's suppopsed to look like a reed valve. A thin metal plate with a screw in it.
 
  #12  
Old 11-15-12, 10:43 AM
sgull's Avatar
Member
Thread Starter
Join Date: Nov 2007
Location: AK
Posts: 2,586
Looking through the parts diagram I did come across the "governor crank bushing," which can be acquired and replaced if necessary, so I was mistaken in my earlier post here when I said it did not have a replaceable sleeve (i.e. bushing). However not sure how you'd actually replace it since it looks like it's a pressed in brass bushing. I suppose with some specialty tool?
 
  #13  
Old 11-15-12, 11:03 AM
sgull's Avatar
Member
Thread Starter
Join Date: Nov 2007
Location: AK
Posts: 2,586
small part found in crankcase

After opening the crankcase I found this down inside laying on the bottom http://i207.photobucket.com/albums/b...psede1636b.jpg
Perhaps someone might be able to help me identify what part this might be, and where it goes? I looked through my parts diagram/list and sure don't see it there. Thanks
 
  #14  
Old 11-15-12, 02:16 PM
sgull's Avatar
Member
Thread Starter
Join Date: Nov 2007
Location: AK
Posts: 2,586
Okay after further inspection it's become apparent that the pin I found is the remnant of the pin from back in the past when the compression release mechanism on the camshaft came off because that pin had come out, and I had to replaced it, and it's been in there ever since. Seems I recall wondering where it ever went, but it must have got itself hidden in maybe the oil plug drain passage or something and until now when it has finally made its appearance.
 
  #15  
Old 11-15-12, 02:29 PM
sgull's Avatar
Member
Thread Starter
Join Date: Nov 2007
Location: AK
Posts: 2,586
I took the head off and looked at the head gasket. It shows no visual indication of being blown. I've had the head off before, a couple of times actually, when having to replace broken valve keepers in two separate instances. But I never have replaced the head gasket, I just re-used it thinking it seemed fine and re-usable. Probably a big no-no to do that. So maybe the head gasket possibly was leaking since it is re-used one? I do remember torquing the head down do spec after replacing it...
 
  #16  
Old 11-16-12, 12:39 AM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 45,088
..........and ? So where are we now ? New head gasket ?
 
  #17  
Old 11-16-12, 07:49 AM
sgull's Avatar
Member
Thread Starter
Join Date: Nov 2007
Location: AK
Posts: 2,586
Yeah new head gasket I guess. Even though it looks fine.
 
  #18  
Old 11-16-12, 10:36 AM
cheese's Avatar
Forum Topic Moderator
Join Date: Jul 2001
Location: USA
Posts: 16,815
I don't know what else it could be. Wish I had a more definite answer. It shouldn't have so much pressure in the engine that it sprays oil out of that spot,
 
  #19  
Old 11-16-12, 10:50 AM
sgull's Avatar
Member
Thread Starter
Join Date: Nov 2007
Location: AK
Posts: 2,586
I've been informed that these engines operate with a "partial vacuum" inside and that if enough vacuum leak is occuring (such as because of leaking gaskets) oil may start to try to push itself out where it can, which in this particular case for this engine could likely be this particular spot there where the governor crank goes through. So my plan is to go ahead and replace the the head gasket, valve cover gasket, crankcase cover gasket, and others as seems needed, do it correctly with proper torque specs, try to get things vacuum tight again and hope that cures the problem.
 
  #20  
Old 11-16-12, 06:29 PM
cheese's Avatar
Forum Topic Moderator
Join Date: Jul 2001
Location: USA
Posts: 16,815
Right... what I said about excessive crankcase pressure. Excessive pressure = loss of vacuum. It doesn't really work under vacuum, just slightly less than atmospheric pressure. Once the pressure becomes more than atmospheric pressure, it blows out.
 
  #21  
Old 11-16-12, 06:38 PM
sgull's Avatar
Member
Thread Starter
Join Date: Nov 2007
Location: AK
Posts: 2,586
So cheese, if I do what I said replacing the engine gaskets, probably a good chance it should fix the issue?
 
  #22  
Old 11-16-12, 07:41 PM
cheese's Avatar
Forum Topic Moderator
Join Date: Jul 2001
Location: USA
Posts: 16,815
If it's letting atmospheric pressure enter the case too fast through a bad gasket, then yes, but it would be a pretty bad gasket. If the head gasket was leaking, it wouldn't have to be really bad. I doubt it was because of any other gasket. The other reason for high pressure would be blowby from bad rings.
 
  #23  
Old 11-16-12, 08:15 PM
sgull's Avatar
Member
Thread Starter
Join Date: Nov 2007
Location: AK
Posts: 2,586
Okay, thanks for replies. Got gasket(s) on order. Might be a while but will post back with results after re-assembly.
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes