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I replaced the crank seal when I replaced the crankcase gasket that was leaking. After the first cut I noticed it started leaking again, when my dad put it on he nicked it so I figured that was it, I bought a new gasket and put it on myself, it went on perfect, I used the old seal to beat it in and it sealed perfect around the crank. I cut the grass the other day and when i was cleaning it I noticed alot of oil in the center of the engine. Now it's so bad that my drive belt is slipping and the mower doesn't move easy. I already ordered the seal, yes it's a briggs and straton factory part, engine is a Briggs 25hp. Just wondering if anyone else has had problems like this and have an idea? Only thing I can think is maybe a rough spot on the crank is cutting it. Will be taking engine out soon. Thanks

My local service tech told me they are finnicky at best. When I replaced one last year on my dad's mower, the tech told me not to be disappointed if it leaked and I had to come get another one. He said if they are not put on perfectly, they will leak. I guess I got lucky as it doesn't leak. All I did was to make absolutely sure the seal went on straight and everything was operating room clean.

Have seen several engines where the crankshaft gets a groove worn into it as well as egg shaping the bearing in the sump. Either due to excessive belt tension or faulty electric clutch that is grounding through the crankshaft causing an arcing effect through the oil film causing a rough surface.

I had one this spring where I ended up putting in four seals, blew out the first three. Finally found that the problem was a plugged oil return line.

Is it better to put it on dry or use some oil to lube it? Thanks

I always install seals with assembly lube. I also put a micro fitch card around the shaft so I am sure not to nic the seal when assembling. The seal slides easily and the card pulls right out.

Rivets said:

I had one this spring where I ended up putting in four seals, blew out the first three. Finally found that the problem was a plugged oil return line.

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I put another on and still leaking, I was wondering where the oil return line is so I can check it, it's not where you drain the oil is it. The crank has a small nick just under where the seal sits, I sanded it down some but thinking that may be the problem. Reason I ask about the return line is the seal looked to be more blown out then ripped. I will be trying to fill the nick with some JB weld or if someone has a better idea, the crank looked brand new besides that with no grooves

Just reread your post and I'm sorry I gave you bad info. Just noticed that you are talking about a vertical engine and mine was horizontal. You will not have a return line. I do have a few questions though. Is the seal leaking on the crank area or the block area? Have you checked to see if you have excess crankcase pressure? Can you post the model numbers of the engine, all three? I think I have some ideas, but I made a mistake earlier and don't want to do it again. Sorry, waiting for a reply. Rivets

The engine number is 446777-0106-e1 the seal is in the crankcase, it's the crankshaft seal that goes over the crank. The original leak was from the crankcase gasket, the crankshaft seal wasnt leaking, I replaced it to be safe. I ordered another seal im going to try to fix the nick with JB weld and sand smooth. I did have a hard time getting this seal in, I will try assembly lube this time

I'm not sure about the crankcase pressure, I don't know how to check it

I guess I have to rephrase my question. Does the seal leak between the seal and the crank or between the seal and the block. If it is the seal and block, you could try try putting thread lock between the seal and block when you install. Are you protecting the seal in anyway when you are installing. It is very easy to nick a new seal when installing. Try these steps. 1. Clean & dry block and crank fully. Use a Q-tip to check for nicks. 2. Apply lube to the area on the crank where the seal rests after installed. 3. Wrap protection over crank from the end to the block. You can use a piece of freezer bag cut and wrapped two layers. 4. Lubricate the inside of the new seal. 5. Slide new seal over the crank protection until it contacts the block. 6. Carefully tap the seal in place until it rests about 1/32" below the block face. Make sure you keep it square. 7. Pull out the protective material. 8. Slide the pulley on the shaft and make sure that the seal is in far enough that the pulley will not touch. I am assuming that you are installing this with the engine out of the unit. If you are leaving the engine in the unit, let it sit for at least one hour before attempting to run. This will allowing the seal to seat. Also, run the engine at low RPM's until the unit is warm, again to help the seal seat properly. Good Luck

it sounds like you might have pressure building up inside the engine, check any vent hoses for blockage

Thanks for all the advice I will be even more careful and take those steps this time,I'm not real sure where it is leaking from, the seal looked to be more blown out this time. I am starting to think it has something to do with crankcase pressure. How would I go about checking and fixing that problem. Also I do this with the engine out and have plenty of clearance to the engine pulley.

If you have not pulled the engine yet, try this. Start the engine and run at 3/4 throttle. Pull the dip stick and rest it on top of the tube. If it bounces up and down, you definitely are building up pressure in the crankcase. Solve this problem before putting new seal or it will blow again.

I just went out and did what you said and once I pulled the dip stick oil started misting out the top. I would say I have too much crankcase pressure. Next problem is I dont know anything about crankcase pressure or what causes too much, but if you could give me ideas I'm sure I can fix it. Thanks for all your help

stang8689 said:

I just went out and did what you said and once I pulled the dip stick oil started misting out the top. I would say I have too much crankcase pressure. Next problem is I dont know anything about crankcase pressure or what causes too much, but if you could give me ideas I'm sure I can fix it. Thanks for all your help

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read my post #12 above

Most common cause lately is a blown head gasket on one of you cylinders. Do you have access to a compression gauge or better yet a cylinder leakage tester? Doing a test on each cylinder will narrow down our possibilities. Also, I would like to know how you would rate yourself 1-10 on your mechanical ability. Sorry to ask, but this will tell me how to proceed.

I am very mechanical at least an 8 I'd say, I know more about cars then mowers, this is my first mower I ever worked on but I rebuilt the engine in my Mustang. I should be able to handle the head gasket job, I do have access to a compression gauge, not with me now but maybe tomorrow. The only vent tube I know is the one to the carb and I just rebuilt the carb and cleaned it even though it looked very clean. My biggest question is when replacing the head gaskets do I need to remove the crankcase and how to I adjust the rockers/ push rods to be in timing? Would I just need the engine gasket kit?

Don't know if I should help a Ford man, I liked my Vette better. Let's take it slow and we should get this done. Wish you would have said cylinder leakage tester instead of compression, but the first thing I would like you to do is take a compression test on each side. This will tell us which side is bad. Don't start teardown till you tell me results, I am not 100% sure it is the gasket yet. Replacing head gaskets will be the easiest part of this job. If you adjusted valves on the pony you should be able to adjust a Briggs. I am going to see if I can find a manual online to help us. Don't buy any gaskets yet, I think we can piece meal this one. Have to warn you, if we do pull a head we should think about a valve job if needed. Make that decision later. Sorry in advance when I revert to my teaching mode, at times I assume people have to be slowly lead through a problem, just the way I work.

My dad is bringing his compression gauge and leak down tester over tomorrow. As for the gaskets I recently replaced the valve covers and exhaust and I believe the carb kit came with new intake gaskets. The leak down test should help the most. I really appreciate all your help and I will post results tomorrow and take your advice from there. I like Vetts too I just painted a 89 for a friend of my dads. Engine has 194 hours if that helps

Leak down tester is great. Sorry one more question. Is this a Vanguard or Intek V-Twin engine? Will make it easier for me to give instructions. Thanks.

Rivets said:

Leak down tester is great. Sorry one more question. Is this a Vanguard or Intek V-Twin engine? Will make it easier for me to give instructions. Thanks.

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It's a 25hp v twin I know you have helped me before but when we get this done I am gonna send you the whole story of everything I've been through with this mower, think this is the 5th problem I've posted, every time I think it's finally done then it's something else but I'm determined to get it right

Down load these manuals. I think they will help us.
http://www.mymowerparts.com/pdf/Briggs-&-Stratton-Parts-Manuals-IPL/446700-ms5195-0205.pdf

273521 Twin Cylinder OHV

It should say Vanguard or Intek on the engine.

Rivets said:

Down load these manuals. I think they will help us.
http://www.mymowerparts.com/pdf/Briggs-&-Stratton-Parts-Manuals-IPL/446700-ms5195-0205.pdf

273521 Twin Cylinder OHV

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Pretty sure it's an intek just went out to the garage and it just says 25 hp ELS V twin Intek sounds famialiar but this link above 273521 looks like my engine exactly

Thank you.

Just got done with compression test I got 80 on the left and 60 on the right, guess he didn't have a leak down tester but the compression was holding until we released it. I checked the vent hose to the air cleaner it was clean and when it's running I can feel a small suction coming from it, let me know what you think, thanks again

The breather tube should have some suction, normal. I really don't like either of your compression test readings. You should be getting close to if not over 100 psi on each side. When you took the readings did you have the spark plug in the other side? Did you make sure that you cycled it through at least 4 compression strokes? Was your battery fully charged? If you say no to any of these I would you to do the tests over. You will have false readings other wise and we may come to bad conclusions. Also, were you able to download a manual from the site I gave you or should I look for a different one?

I had a fully charged battery I did at least 6-8 compression strokes, I did have both plugs out but I just when out to the garage and with the other plug in I got the same results, I had no problem downloading the manuals. Do you think I should just do both head gaskets or could it be something else

Let's just do the right side first, and we'll decide after you tell me how it looks. If you really want to do this pull the right side head following the instructions in the manual. Make sure that you label the push rod so you know which is which. Do not remove the valves from the head. Do you realize that I may be asking you to recondition or replace the valves after you tell me what they look like?

Rivets said:

Let's just do the right side first, and we'll decide after you tell me how it looks. If you really want to do this pull the right side head following the instructions in the manual. Make sure that you label the push rod so you know which is which. Do not remove the valves from the head. Do you realize that I may be asking you to recondition or replace the valves after you tell me what they look like?

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Thanks for giving me a heads up with the valves, where would I get them reconditioned? Would it be possible to clean the valves if needed, I would rather do both sides at once but I'm guessing you want to see the results of the worst side first before I waste my time. I won't be able to do this until Friday or Saturday but I will post some pics. Thanks

We can do both sides at once, just want to know what I'm getting in to first. If we need to recondition the valves we need the best small engine rebuilder in you area. Ask around. It shouldn't cost a lot, just want someone who really knows what they are doing. Some of your auto builders may have cutters small enough. Remember I use to teach this and have to justify my decisions. Don't want to jump to conclusions, could cost big bucks if I tell you wrong. Not my money, so I double check and pray I'm right.

Thanks again for all your help, Im on the road all day for work and know of a few small engine repair shops that have been in business for along time.

Next two days are 9 hours plus, will look for your post this weekend.

Sounds good to me thanks again

I got both heads off and took some pictures, I'm not good at posting pics on forums but I can email them to you from my phone if you don't mind, if you don't want to make your email public you can pm it to me, let me know if that's ok with you.

Sorry I haven't gotten back to you, just got home from work. 33 hours in the last three days, and have to go back in tomorrow. Good customer blew two Kohler 25 HP engines Wednesday and have been rebuilding totally last three days. Plus today we sold nine units. The two Z's and one tractor had to go out today and the rebuilds have to been ready to install Monday. You can send me pics to me, I'll pm my email. How do the heads look? Try to get real close-ups of the valve heads and cylinder walls. I'll try to get back to you tonight if I don't fall asleep.

I will send them now. The top of the pistons had alot of crud on them, all the cross hatching was on the cylinder walls. When I replaced the crankcase gasket everything from underneath looked brand new including the walls so i was surprised how it looked. Head gaskets weren't noticeably ripped but nicked on the edges.

Haven't seen pics yet. Off to work, won't be home til late. Try to look for them when I get in.

Ok no problem thanks for keeping me posted

Waiting for pictures???.

Sent again sorry it didn't go through

Got the three pics. Doesn't look bad, in fact the valve look good. Haven't got time to really put together a post on what to next. I'll try to post a procedure tomorrow. Just got home from another 12 hour day and my brains fried. Sorry.

That's no problem, glad you got the pics, glad it doesn't look bad. Take your time and whenever your up to it I look forward your post.

First, I am assuming that the pics you sent are all from the right side. I see some evidence of a blown gasket, but really think that the valves should be able to go back in just the way they are. Bring the piston up to TDC level with the top of the block. I would scrap the top of the piston carefully with a putty knife, no gouges. After scraping clean the top of the piston. I use 0000 steel wool and carb cleaner, but can use any type of cleaner which will do the job. Also clean the area where the gasket was attached. After you have cleaned the piston, move it down to BDC and clean the inside of the cylinder. I start with a soft rag a light cleaning solvent (nothing harsh), just something to get it clean. Many people like to use a lubricant like WD-40 which will clean and protect. After cleaning dry with a soft rag and apply a thin coat of motor oil to prevent corrosion while it is standing open.
As for the head the only thing I would do there is clean the gasket surfaces, and leave the valves alone. If you want to tackle the other side go for it. Any time you let it sit cover with rags. Now would also be a good time to order the gaskets you will need. Your supplier may have to order some not in stock. I suggest head gaskets, valve cover gaskets (if they are used, some use an RTV sealant), intake and exhaust gaskets, any you have removed. Also, clean the head bolts. Any other questions at this point?

Thank you so much for the write up, I understand everything you said very similar to changing heads on a car, just a few simple questions. Should i just scrape and scuff the gasket surface or would it be ok to use a small round abrasive pad on an air die grinder like I do when changing heads on a car or could that be too much.? I would use a fine grit of course, and when I'm cleaning the pistons would it be ok to use a wire brush wheel with my drill? Its not real rough and shouldn't remove any medal. As for the valve cover and exhaust gaskets, I recently put new ones on and no rtv was required, they came off very nice and still look brand new, both sides, should I still buy new ones or could I reuse them? Should I clean the top of the valves with anything? On last thing, I would clean the head bolts on a wire wheel on my bench grinder, now when I'm torquing them is there any sequences? On my car I had to do 3 different settings and in a certain order, thanks agian

Scrape but not scuff the gasket surfaces. No abrasive pads, want then smooth as possible. No wire brush on the piston heads, I only use hand wire brush if I have hard carbon. I have always taught students that the slow patient way does a better job. The valves look so good in the pics that unless you see carbon build up I would leave them alone. Wire wheel on head bolts fine, we want them clean and dry. Want to install them dry. Can reuse gaskets if you feel they are good. Should have torque specs and sequence in the manual I asked you to download. Let me know if you can't find.

I remember seeing the torque specs but just what they were to be torqued too, one more question the head gaskets could cause lower compression? you don't believe the piston rings could be bad?

In the on line manual go to section 13, page 5 for sequence and torque value. Also has valve adjustment sequence. I don't think the rings are bad, but try this after cleaning everything. Bring the piston to TDC and try to move them left to right and top to bottom. There should be some play but not a lot. Sorry this test comes with experience and feel, you will have to make the decision. Right now I'm going by looks only.

I ordered the gaskets so as soon as I get them I will be putting them on so I'll either be posting results or asking more questions, hope to have by Saturday but if not then next week, thanks

Did you find the torque specs and sequence in the online manual? The procedure for adjusting the valves is in the same area. If it takes you less than 20 minutes to set the valves you are either very good or going to fast. After you think you have them adjusted properly rotate the engine by hand through at least 4 complete cycles and recheck clearances. Many times they will have changed due to sticking during reassembly. I use assembly lube (Permatex Ultra Slick) on everything that moves without threads, including a coat on the cylinder walls. Remember to dry torque the head bolts.

I found the specs thanks, I will get some assembly lube as well. I will make sure to recheck the valves thanks for reminding me about that I forgot about that. I feel confident I can do this with all the info you have given me, you are very thourough with the details, just hope this does the trick

Just got the head gaskets in the mail, going to get started soon. I just reread the manual and only question I have is when adjusting the valves it says to have the piston 1/4" past TDC, so im assuming that means to have the piston go down 1/4" after it reaches the top. I thought it was supposed to be set at TDC but after rereading I noticed it said 1/4" past TDC. Thanks

Manual is correct 1/4" passed TDC. This is to allow for compression release. Good Luck

Got a lot done today I spent a lot of time cleaning everything up, got it looking almost like new with the carb cleaner and 0000 steel wool, I cleaned the cylinder walls and applied the assembly lube, got the heads on but then realized my 1/2 inch torque wrench couldnt go less then 25 ft/ib and I needed 18 for the heads, I found someone I can borrow a 3/8 inch torque wrench from on Monday. One quick question how to I know when the piston in 1/4 inch tdc, do I measure 1/4 inch on a small screwdriver and mark it and stick it through the spark plug hole?

Just about that way. This one does not have to be that exact. I justbstick a screw driver though the spark plug hole and watch when the piston starts going back down. Rock it back and forth a couple of times and make your best guess.

Well now I have another problem, I got the correct torque wrench, I did it in 2 steps torquing half spec to full spec in order, I got the first head done no problem, on the second head just about done on the last bolt and waiting for the click any second then snap, the bolt snapped. I ordered another bolt and I'm going to have to find a bolt extractor tool somewhere, not sure if the bolt was weak or the wrench is junk, I cleaned really well. That's my update hope to get this fixed soon.

Best laid plans of mice and men always go @&$)(;:/-. Hope things work out.

I knew something would go wrong ,it always does but if it turns out to be a $6 bolt and some fun removing a bolt then I'll be ok.

Be sure you are in the correct range for your torque settings. Inch pounds and ft. pounds are obviously not the same critter. I've done this mistake myself.:ashamed: Nothing on this planet is more fun than extracting a small diameter broken bolt.

I had converted the in/ib to ft/ib no problem just a pos torque wrench I found someone with a better one. I actually removed the bolt very easily, good thing i had it nice and clean

I didn't want to jinx you by saying it should come out easy if you cleaned it. Good luck in the rest of the procedure.

stang8689 said:

I had converted the in/ib to ft/ib no problem just a pos torque wrench I found someone with a better one. I actually removed the bolt very easily, good thing i had it nice and clean

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Ah, good.:wink: I just wanted to point that out, especially since I'd done it to myself.:biggrin:

Just got the new head bolt i am off all day Saturday and plan to get this done

I'll say it, good luck.

Well I got everything back together today, bad news is I did a compression check before I started it and I was getting only 30-60 and it wasn't holding the pressure. I did get it started and it sounded great but when I pulled the dipstick oil was still misting out the top. I took my time on everything and followed all the instructions, any idea what I could of done wrong? I really can't afford to put much more money into this I may just have to sell it and downgrade. Thanks for all your help either way, I'm open to any ideas of things to check or maybe it has to run a while?

Let's not get down yet. I'm a little more positive than you are right now. I don't think you did anything wrong. You did a compression test when the cylinders were dry from the cleaning. You said it sounded great, let's do another test. Put a little motor oil into each cylinder, spin the engine over a couple of times with the plugs out and take another compression test. I think we will find the compression go up. As you run the engine the motor not only lubricates, but also seals between the cylinder walls and the rings. Your original post was for leakage around the seal. Do you see any evidence of leakage around the seal? If not that is a good sign. A little misting is not bad. Don't run over 3/4 throttle for the first 30 minutes and take a third compression test. I know that this sounds redundant, but if it sounds great we may just have to allow it time to settle in. Remember I told you we had to take it real slow. May be a dumb question, but when was the last oil change?

I will try putting some oil in the cylinders and see what happens, the seal wouldn't start leaking until after I cut the lawn and it ran for a while. I was going to put the deck on and try cutting the lawn and see if it leaked the next day, I did put assembly lube on the walls. As for the oil change I drained the oil before removing the engine and put fresh oil in, before that the carb went bad so I did a filter and oil change the cut before pulling it this time. The only question I had while putting the engine back together was after adjusting the valves it said to torque to 60 in ib but I couldn't torque the nut, I watched a few videos and everyone just tightened the nut with the wrench, could I have over tightened the jam nut.? I tightened it tight but didn't over due it, I also double and triple checked the clearances after several engine rotations.

Good about fresh oil, wasn't sure. Assembly lube protects during reassembly and startup, but burns away or dissolves very fast. Don't think you overtightened the valve nuts, as long as the clearances are correct. I would put the deck on and give it a workout. Don't run at full throttle for the first 30 minutes and when your done cutting take the third compression test. Stay positive.

Ok I will do that in the next few days and thanks again for all your help.

Well i don't have any bad news to report, I mowed the lawn yesterday, it had even more power and was faster. Today after work I came home and looked real good and can't see any signs on any oil leaking. So maybe I got lucky and fixed it but I'm still holding my breath. I wont really know until I use it a few times to know for sure but I am very happy at the current results. Thank you so much Rivets for all your help and I will keep you posted.

Super! I hope it holds in there for you!:thumbsup::biggrin:

I told you to stay positive, I've been through this too many times and over 90% work out the first time if you go slow and don't skip steps. Not a bad job for a Ford guy, even they get lucky once in a while. Congratulations.

Thank you so much for all your help I wouldn't of been able to do it without you, everyone on this forum really appreciates all the time you take to help others and pass on your knowledge. I wanted to fix it for you almost as much as myself.

Just an update, I cut the grass again a few days ago and still no signs of leaks, the mower runs and works perfect, I have not done any more compression test because it seems fine and don't want any bad news. So thanks again to Rivets you saved me big time.

Glad to help out.