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    Valve Cover Gasket Leak

    500 miles of dry riding after my valve adjustment and new OEM Gasket, I've sprung a leak. At first I was sure it was the tacho drive seal that I neglected to change out when I had everything apart. The bigger one in this pic:


    There was definitely oil coming from around the base of the tacho drive housing. So I went to my dealer and they surprised me by having one in stock. I swapped it out. along with the small o-ring 'cause why not?

    Cleaned everything up, put the bike on the center stand and fired it up. In a short amount of time i was still getting drops of oil dripping from the the valve cover gasket on to the header below and smoking. But it was hard to tell exactly where the gasket was leaking. Then I remembered reading about using powder to find gasket leaks. So I cleaned everything up, let it sit and dry for a day and powdered the gasket area all along the sides and front, even at the half moons. Here's a short video which shows the leaks, I believe just below and to the right and left of the tacho drive. Of course it could be one leak that runs along the gasket and drips from more that one place.


    The valve adjustment I did was my first ever attempt at this. And I thought that I did it very carefully and correctly (except for the neglected tacho drive seal already mentioned)

    My Thoughts:
    After I did the valve adjustment, I thought I did a decent job of cleaning off all of the old gasket, and replaced the gasket with OEM part # 11173-49224-H17. I used a thin coating of this grease on both sides:


    I think all that was good.
    I kept all the bolts on a carboard map and I'm fairly confident that they all went back where they belonged. I used a thin coating of RTV silicone gasket maker on the half moons, installed them as per the manual (I know that some folks flip the flange to the inside of the engine.) The half moons appear to be dry.

    Since I don't have an inch-lb. torque wrench, I used what I believe to be the conventional wisdom for tightening the valve cover bolts. Just snug, then a quarter turn more. And, as stated, I have ridden the bike, sometimes pretty hard, for 500 dry miles.

    When I first discovered the leak, I think I may have made a mistake by tightening all of the valve cover bolts another quarter turn or so. I don't think It's made the leak any worse, but I don't think it's gotten appreciably better either.

    So I think what I need to do is:
    1. Buy another gasket.
    2. Make sure both head and cover surfaces are absolutely clean.
    3. Re-check valve clearance 'cause I'm a noob and don't trust myself.
    4. Grease or no grease on the new gasket???? Or something different: WD-40, PB Blaster, or Dry?
    5. Buy or borrow an inch-lb. torque wrench and torque bolts to spec. I think that would be 84 inch-lb?

    I'm really not sure exactly what I did wrong. I sure that someone here can tell me. I was so proud of myself once I got everything buttoned up and rode the bike with no problems, now my confidence in my mechanic abilities is shaken.

    Thanks for reading.
    Last edited by Rich82GS750TZ; 06-11-2019, 07:34 AM.
    Rich
    1982 GS 750TZ
    2015 Triumph Tiger 1200

    BikeCliff's / Charging System Sorted / Posting Pics
    Destroy-Rebuild 750T/ Destroy-Rebuild part deux

    #2
    FWIW, I've never used an inch-pound torque wrench on 6mm bolts and the only time I tried to, turned out the torque wrench was horribly under-reading so immediately stopped using it before any damage happened. Just as well I'd developed a good feel for the right tightness without a t.w. else things would have been disastrous.
    Anyway, my point is that 'just snug, then a quarter turn' is perfectly ok. Rather slightly too loose than over-tight, with these. As the gasket beds in, the bolts slacken slightly anyway, and while the book figure might well cater for that, it's good practice to bear in mind that the bolts need to be checked and re-tightened after a couple of hundred miles, especially if hand-tightened. No biggie, it's just something you do, and get used to.
    I've never had a valve cover gasket leak through doing it this way, but seperately have had the tacho drive start to leak and gradually get worse so it spreads all over the front and top of the engine, making it appear as if it's leaking from everywhere up top.
    ---- Dave
    79 GS850N - Might be a trike soon.
    80 GS850T Single HIF38 S.U. SH775, Tow bar, Pantera II. Gnarly workhorse & daily driver.
    79 XS650SE - Pragmatic Ratter - goes better than a manky old twin should.
    92 XJ900F - Fairly Stock, for now.

    Only a dog knows why a motorcyclist sticks his head out of a car window

    Comment


      #3
      On your video, that gasket doesn't seem to fit very well at the ...the "cam-chain tunnel"? Is there a lot of overlap? There shouldn't be any overlps sticking out on a gasket you bought.

      so..ideas...if I've observed correctly
      A)Best guess: it's the wrong gasket? Not sure on your bike but on mine, the valve cover changed between 81 and 82 and it's easy for someone to give me the wrong one...double check changes in part numbers on an online parts diagram to see if this is possible....
      B) it's almost possible to get the gasket back to front...it won't quite fit-it'll look wrong...

      Torque? I doubt that's your issue on a new gasket. It'll seal... But the gasket seems to live way longer for repeated valve checkes or whatever, if you torque it lightly. I love my inch/lb torque wrench. 6 ft/lbs can't be done on a big wrench but 72 inch/lbs is easy to dial in on a little one. I would have torqued way to hard guessing but the wrench has instructed me so I could do way better now, if I had to.
      Without a wrench, I'd do it lightly,lightly evenly and only if it weeped would I go round again and give the wrench the same light tap or twist for each.

      Comment


        #4
        Odd idea: lacking a torque wrench, if you attach a spring to the end of a wrench, and measure it's stretch, you can at least torque bolts to the SAME...ie: an angler's fish- weighing spring scale come to mind...but a new digital one might do to.
        It's going overboard, but someone "deep in the woods" could have a collection of springs calibrated to suit their solar panels,guns and windmill etc.....Too "Deep-in-the-woods", I guess.

        Comment


          #5
          AFAIK, I have the updated gasket. I think the newer design has more bolts, correct? Everything lined up fine, but your observation about the corners of the gasket at the "cam-chain tunnel" at the front is the only place I could see that there was any over-run of gasket. I don't recall what it looks like at the back. When I first placed the gasket in wouldn't go over the 2 alignment dowels (oil chases?) until I flipped it what I thought was the right way. At the time, I believed it was the only way the gasket could go on.
          I just found a picture of the gasket on Amazon that tells me that I was wrong. I should have spun it around 180 deg, then the round part would have been at the front, putting the square part visible in my video poking out the front, to the back.

          I will be hunting for a inch-lb. wrench. But I'm still not sure what best practice is for "greasing" the gasket. The gasket I bought was labeled as OEM from Babbitts (Suzukipartshous.com). 11173-49210 superceded by 11173-49224-H17.

          Thanks Gorminder and Grimly for making me take a more in-depth look at the issue. I really appreciate it.

          Still entertaining any and all thoughts and input on my mess.






          Rich
          1982 GS 750TZ
          2015 Triumph Tiger 1200

          BikeCliff's / Charging System Sorted / Posting Pics
          Destroy-Rebuild 750T/ Destroy-Rebuild part deux

          Comment


            #6
            Well,mostly I don't bother but Grease does no harm on the brown/tan-paper gaskets I use....something that wont WELD itself to the engine (silicone can do this! and the black gaskets seem to do this too, judging by the bikes I've bought and had to remove these...maybe just old, overtorqued? but I avoid them in hot places if I can.. ...felpro makes stuff for this and I've used it smeared on thin...it doesn't seem to weld itself and helps especially in tricky places ..vertical surfaces and areas I can't poke and prod the gasket into place...

            The thought that occurs often,every time I take the cover off is, If I wanted to tack a gasket down,and have it stay when I remove the cover, I would want it to stick lightly to the engine so that when I removed the valve cover, it wouldn't lift off stuck to the cover but also stuck to the engine AT THE LOCATING DOWELS(the hollow tubes sticking up at two or more bolt holes) Without anything, it often tears the gasket and also, while I remove the cover a bit of loose gasket hanging down always catches the valves and all.

            But, last time, I remembered these details and with a thin painters spatula I just untstuck it gently from the cover to stay on the engine. Remembering is best of all.

            Comment


              #7
              Taking another look at the gasket picture, rotating it 180 deg. would put the squared bit at the back but would put the 4 center holes would not line up. flipping it front to back would mis-align those holes and also the LOCATING DOWELS, which are the far left and right holes in the picture. so now what?
              Rich
              1982 GS 750TZ
              2015 Triumph Tiger 1200

              BikeCliff's / Charging System Sorted / Posting Pics
              Destroy-Rebuild 750T/ Destroy-Rebuild part deux

              Comment


                #8
                I have little use for a 1/4 inch torque wrench, so here's what I use..I do in two go's, starting inside and working my way out.
                image.jpg
                1981 gs650L

                "We are all born ignorant, but you have to work hard to stay stupid" Ben Franklin

                Comment


                  #9
                  ^ ^^aha! that's what I was thinking!! Cute kit!

                  Comment


                    #10
                    Thanks tom, that is clever. I think for $20 and a little more accuracy, I'll pick up a 1/4 drive inch-lb. wrench at HF.
                    Rich
                    1982 GS 750TZ
                    2015 Triumph Tiger 1200

                    BikeCliff's / Charging System Sorted / Posting Pics
                    Destroy-Rebuild 750T/ Destroy-Rebuild part deux

                    Comment


                      #11
                      yes, but I bet that device could get into some really strange little corners... maybe the camchain tensioner bolts...that's one that comes to me..or carb drain bolts..nobody wants to strip those! This might bug me til I make one too

                      Comment


                        #12
                        By the way, anti-seize compound might be an idea on a gasket you don't want to stick vs just grease. (I keep forgetting to try this)

                        Comment


                          #13
                          OK. So I had some time tonight to pull the valve cover and inspect the gasket. The grease I used seemed to to a good job of making it easy to remove. But i found two serious tears and mangled gasket where the powder showed the leaks and a tear on one of the left front bolt holes as well.




                          What the pics show is that I evidently had some problems when tightening the bolts initially around the front part of the engine. I'll have to be more careful when I get the new gasket. I'd like to think that I would have noticed the gasket moving so much the first time. But it was exactly that, my first time. Any more advice on installing the new gasket to make sure it stays put and doesn't squirm around as I tighten the bolts? I know to go a little at a time working criss cross from inside to out when tightening the bolts.
                          Rich
                          1982 GS 750TZ
                          2015 Triumph Tiger 1200

                          BikeCliff's / Charging System Sorted / Posting Pics
                          Destroy-Rebuild 750T/ Destroy-Rebuild part deux

                          Comment


                            #14
                            " I know to go a little at a time working criss cross from inside to out when tightening the bolts."

                            Double check for clean gasket surfaces - took me longer to do this than everything else.
                            holding a socket in your fingers, work from inside out to corners...get them all even to finger touch and then break out that new HF Chinese 1/4 inch drive torque wrench to finish. Second time is a charm!


                            1981 gs650L

                            "We are all born ignorant, but you have to work hard to stay stupid" Ben Franklin

                            Comment


                              #15
                              Thanks Tom. With luck, I'll have the gasket by Saturday and be riding by Sunday.
                              Rich
                              1982 GS 750TZ
                              2015 Triumph Tiger 1200

                              BikeCliff's / Charging System Sorted / Posting Pics
                              Destroy-Rebuild 750T/ Destroy-Rebuild part deux

                              Comment

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