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Thread: Push rod tube seal 1986 R80

  1. #1
    Phil B bullfrog_28560's Avatar
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    Push rod tube seal 1986 R80

    Hello all, I was wondering if there is an easier way to replace the tube seals? I looked in the haynes, it does not really cover replacing them, just looking at it it looks like i have to remove the cylinder jug to replace them. If there is a way that I do not see, please let me know, It looks like fun from my view.
    Phil Bouffard
    SSG U.S. Army
    Kaiserslautern, Germany

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    Administrator 20774's Avatar
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    Oak sells a pamphlet that is a step by step guide to this. $25 last I checked. Worth it...email him at
    askoak at aol dot com.
    Kurt -- Forum Administrator ---> Resources and Links Thread <---
    '78 R100/7 & '69 R69S & '52 R25/2
    mine-ineye-deatheah-pielayah-jooa-kalayus. oolah-minane-hay-meeriah-kal-oyus-algay-a-thaykin', buddy!

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    Old man in the mountains osbornk's Avatar
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    My 86 R80's tube seals leak with sythetic oil but they don't with conventional. It has been leak free for the last 13+ years.
    'You can say what you want about the South, but I almost never hear of anyone wanting to retire to the North.

  4. #4
    Phil B bullfrog_28560's Avatar
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    Funny thing is i changed the oil due to oil pan gasket leaking, it was crispy, i replaced the oil with standard non synthetic oil, now it leaks from the tubes, it was at first leaking badly past the dip stick o ring, had to replace that as well. after wiping down the new oil leaks and test driving it after replacing the o ring, the passenger side push rod tube is leaking, i do not think any of it has been replaced, 26 years old, somethings bound to leak. if there are any step by step procedures to replace that i do not have to pay for thatll be better.

    Looking at Oaks pictures of topend disassembly your almost rebuilding the motor if you have to replace the seals, your removing the piston from from the rod. is there a way of replacing the seals without having to go that far and still be done correctly?

    ALSO is there a crankcase vent I am not seeing in the manual that might cause excess pressure to leak?
    Phil Bouffard
    SSG U.S. Army
    Kaiserslautern, Germany

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    Actually . . . .

    In bringing my R100RT back I had to replace the push rod tube seals. Of all of the projects it was one of the easiest jobs.
    Follow the directions in Haynes and buy a ring compressor or a big radiator clamp and you will be OK. Note arrows on top of piston.
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    Here is a recent thread talking about pushrod seals and the involvement (or lack there-of) needed: http://www.bmwmoa.org/forum/showthre...ferrerid=51262

    I recently replaced mine but only needed to slide the cylinders from the engine casing and then slide them back. My 78 has no cylinder o-rings or gaskets, just Hylomar (which is available but not that easy to get). The push rod o-rings were in good shape, so I left them alone. I am not sure what subtle differences there are for a '86. I read Oaks guide carefully, but have taken the cylinders off before many moons ago -before Oaks guide existed. It's not that tough, but Oak does have some good pointers. One point he makes is not using any hammer other than rubber. I needed to use a rubber hammer (mallet) to coax my cylinders away from the engine housing. Cleaning off and reapplying the Hylomar was the biggest part of the job.

    Here is a pic of the job mid-way through:
    Attached Images Attached Images
    Stan

    AH# 13238

  7. #7
    blah blah blah squiffynimrod's Avatar
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    1985 R80RT/ 2002 R1150GSA
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  8. #8
    '92 R100GS '81 R100/t brittrunyon's Avatar
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    Quote Originally Posted by squiffynimrod View Post
    Wow, that's a great step by step photo guide, but..........

    I only slide the heads/cylinders back a few inches to access the seals
    Note: there is no gasket or Hylomar bwt head & block just o-ring on cylinder head bolt.
    (92 GS)
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    Registered User lkchris's Avatar
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    The answer to the original question is ... there's no easier way.

    It's simply foolish to not replace the cylinder stud and cylinder base o-rings at the same time.

    And, I wouldn't call the process "difficult" in any event.

    A push-on-from-bottom ring compressor is < $30 from Snap-On



    http://buy1.snapon.com/catalog/item....re&dir=catalog
    Kent Christensen
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    '12 R1200RT, '02 R1100S, '84 R80G/S

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    Quote Originally Posted by lkchris View Post
    The answer to the original question is ... there's no easier way.

    It's simply foolish to not replace the cylinder stud and cylinder base o-rings at the same time.

    And, I wouldn't call the process "difficult" in any event.

    A push-on-from-bottom ring compressor is < $30 from Snap-On



    http://buy1.snapon.com/catalog/item....re&dir=catalog
    Wow. Really?

    If someone feels the need for complete disassembly to replace the seals, the previous site linked is the way to go: http://www.pbase.com/dqmohan/prtseals or read a Haynes, Clymer or BMW repair manual.
    Stan

    AH# 13238

  11. #11
    Registered User beemerguru's Avatar
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    Easiest way to to remove exhaust headers, bundgie carbs away from head, remove spark plugs, remover rocker arms, pull entire head and cylinder assembly away from block until wrist pin is visible,,remove one of the keepers, push wrist pin out till rod if free (make sure rod doesn't slam down and dent the mating surface), slide assembly rest of the way off.

    Clean all surfaces, check cam followers for perfect surfaces, apply very thin layer of Hylomar to base of cylinder. (personal preference, I use assembly lube when installing pushrod seals since they have to move very slightly due to temp differential). Never had one leak. Install large (if needed) O ring and the 2 small ones..the Hylomar will hold them in place.

    make sure the small top O rings are in place,,push head/cylinder assembly back on the rods until you can position rod in piston..push wrist pin back in..make sure it's all the way in and seated, install NEW wrist pin keeper, push head until cylinder is closely seated against block, install pushrods back in same holes,,install rocker arms..torque properly (3 stages), install headers, install carbs. Leave rocker arm covers off when restarting engine - oil passages are part of the top engine studs so you want to make sure any HYlomar or crimped small O ring hasn't clocked the hole..run engine for maybe 30 seconds and you should?better have a small stream of oil running down each rocker arm.

    Place Teflon cookie pans under each head to catch the oil..if you want to run the engine like this for a couple minutes...you can then wait for a total cool down and retorque the heads..then go for a 3K mile ride and check the heads then.
    Greg Hutchinson
    R80G/S (4) 633CSi with 450K mile
    '68 R60/2 '88 K100RS Special Edition
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  12. #12
    Bluenoser
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    Quote Originally Posted by bullfrog_28560 View Post
    Funny thing is i changed the oil due to oil pan gasket leaking, it was crispy, i replaced the oil with standard non synthetic oil, now it leaks from the tubes, it was at first leaking badly past the dip stick o ring, had to replace that as well. after wiping down the new oil leaks and test driving it after replacing the o ring, the passenger side push rod tube is leaking, i do not think any of it has been replaced, 26 years old, somethings bound to leak. if there are any step by step procedures to replace that i do not have to pay for thatll be better.

    Looking at Oaks pictures of topend disassembly your almost rebuilding the motor if you have to replace the seals, your removing the piston from from the rod. is there a way of replacing the seals without having to go that far and still be done correctly?

    ALSO is there a crankcase vent I am not seeing in the manual that might cause excess pressure to leak?
    You don't have to take the head off of the cylinder. Just undo the 4 bolts that hold on the rocker arms, carefully pull the cylinder back with the head attached until you can just see the circle clip on the connecting rod/piston and go no further. The piston pin will only push out one way and is identified by the notch in the piston. Carefully remove the circle clip ( shouldl be replaced with a new one, most don't ) and then gently tap the piston pin out and remove the piston with the cylinder head assembly. You don't want to disturb the rings, if you pull it out so far that the rings are exposed then they should be replaced. As you slide this back on the head bolts stop and as the pushrod tubes are clear of the seals they are easily replaced. Repeat the above to get the head/cylinder/piston back into place.
    1971 R50/5 SWB with R75/6 drivetrain
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  13. #13
    Administrator 20774's Avatar
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    Do you have any concern for leaving the 12 and 6 o'clock bolts fully torqued while the head/cylinder is off? I would be for possible head warping if it is left that way for too long. Hard to say what is too long...unevenly torqued can't be good.

    For the price of a set of head gaskets, undo all bolts and pop the head. Now do the circlip/wrist pin thing. You'd even get a chance at decarbing the head.
    Kurt -- Forum Administrator ---> Resources and Links Thread <---
    '78 R100/7 & '69 R69S & '52 R25/2
    mine-ineye-deatheah-pielayah-jooa-kalayus. oolah-minane-hay-meeriah-kal-oyus-algay-a-thaykin', buddy!

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    Quote Originally Posted by 20774 View Post
    Do you have any concern for leaving the 12 and 6 o'clock bolts fully torqued while the head/cylinder is off? I would be for possible head warping if it is left that way for too long. Hard to say what is too long...unevenly torqued can't be good.

    For the price of a set of head gaskets, undo all bolts and pop the head. Now do the circlip/wrist pin thing. You'd even get a chance at decarbing the head.
    The gurus seem to think that two hours is the time limit if going the rocker bolt route. No idea how they come to that conclusion. Seems best to me if you just do the rocker bolt route then a stone cold engine would be a good idea, and work briskly! Many pushrod tube seals have been replaced this way and I have not read/heard of any problems.
    Last edited by R100RT_Mark; 10-25-2012 at 04:47 AM.
    Mark

    Current - 1974 TR5T : 1993 R100R : 1994 R100RT ~ Past - 11# 1970s BSA/Triumph Singles & Twins : 2# 1970s CZ 125s : 1# 1985 BMW R65 : 1# 1976 Moby X7

  15. #15
    Administrator 20774's Avatar
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    I see where Snowbum says he "approves" if not more than 2 hours. One minute, two hours, 24 hours...untorqued is untorqued but I suppose it could be done. My issue is the work "briskly" note! I hate to rush myself on these kinds of things. Inevitably, something comes up, I don't have the part, or have to get onto something else in the meantime...then I'm working every more briskly, heading for a possible ef-up.
    Kurt -- Forum Administrator ---> Resources and Links Thread <---
    '78 R100/7 & '69 R69S & '52 R25/2
    mine-ineye-deatheah-pielayah-jooa-kalayus. oolah-minane-hay-meeriah-kal-oyus-algay-a-thaykin', buddy!

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