Oil sight glass - take 2 - your experience on fitting a new one on an older bike

Hi all, I know this has been all over the internet, yet I need to clarify on one thing before I mess another sight glass up. From your experience - did you use any lubricant / sealant to help the sight glass slip / remain sealed on an older bike (namely R1150GS in this case)? Most sources say not to use anything on it, no oil smear, etc. I've removed the old one that was all crooked and leaky, installed a new one after cleaning the edges with fine sand paper, wiped with rubbing alcohol, scouring pad, alcohol, smear of water and in - went in almost perfect, but on further installation (30mm socket) it produced a lip on top right corner, didn't leak at first, but started leaking when hot (as one would expect...). Got another one now, will be installing it today or more likely tomorrow, just want to know if you've got any tips or did I miss something. I don't fancy destroying another one.... Any help appreciated.

I've no experience with this particular job but I use rubbing alcohol as lube for tight seals that are recommended to go in dry (ie no oil) - aids installation and then evaporates without residue.

Brake cleaner works just the same.

brake cleaner will ruin (swell) rubber and some plastics. not good for seals at all IMO

I put grease round mine before fitting it - was several years ago and has been fine ever since.

I was going to use slight smear of rubber grease, but then again this is only held by the way it sticks to the (old and oxidised) walls, then normally you could use a smear of oil - but - same as previous. Some people mentioned smear of water (spit, literally - did that, didn't work as well...). The fact that it started to leak and the fact it didn't sit well brought me to conclusion to use some RTV silicone, that should help slipping the bloody thing into place, but when I spoke to a guy who used to work for BMW he said they've used brake cleaner to spray the hole and then inserted the sight glass... Goes in line with what jaak said, it evaporates as well, so shouldn't do much damage, rubber on the ring should be safe, it ain't just rubber, must be tougher to withstand temperature and pressure (or so I think), plus when it evaporates it can't do much harm in a short time?

Frightening part it's just a start, I've tried installing crash bars and bolt (underneath the tank) snapped right away - other one will - so here comes the drill; not the easiest welcome to the family but will keep at it, as it's a great bike. Will probably see you guys (or you will see me) more often, thanks for all replies, I gotta say this is way more informative than most communities than I've been through in the past lives; I'm glad as I'm planning to settle here.

I'll let you know tomorrow how it went, as said, don't fancy getting another one so got to be right this time. Will go with either rubbing alcohol or brake cleaner - I take it that nobody used the sealant or RTV of some sort? I was wondering if due to oxidising it might be more porous than new metal and needs a bit of extra filling to smooth out imperfections, but then again, rubber should decompress into all tiny grooves and imperfections, shouldn't it?

I'll be interested to here how you get on. My view is....if there is oxidation on the surface of the metal, use some RTV type sealant, only a tiny amount should do it.
Good luck Sortster !

If you're worried about brake cleaner affecting the rubber, get some Finish Line Citrus Degreaser in a spray can. Lubes. evaporates and sticks rubber to metal rather well.

You're over thinking it.

Just hit it in straight and all will be well.

Steptoe said:

You're over thinking it.
.

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Quote of the weekend

I am guilty of that. Over thinking is one of my gifts - next to OCD, can't tell you how much that little lip on the rubber annoyed me even way before it started to leak... ) Off to do it finally today. Together with alternator belt, gearbox and final drive oil and LEDs to replace instrument cluster lights (half of them dead, let's make them red). Will post results. Last thing, 30mm socket over it or straight piece of wood to hammer it in? Tried the socket, held it square and messed it up, so wondering (over thinking mode on full power) should I change the approach or just whack it straight in with a sledge (rubber, kidding... ).

a slight smear of fairy liquid

fizzer said:

a slight smear of fairy liquid

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Very true.. I was shown that way by John Hill at Bracken many moons ago, he smeared a tiny bit of fairy liquid round the glass.. Offered it up using a piece of wooden doweling very slightly smaller than the oil glass.

He tapped the doweling / glass with a rubber mallet.. Sorted.

Took all of 10 seconds..

Best of luck

Dave.





Dave.

sorter said:

I am guilty of that. Over thinking is one of my gifts - next to OCD, can't tell you how much that little lip on the rubber annoyed me even way before it started to leak... ) Off to do it finally today. Together with alternator belt, gearbox and final drive oil and LEDs to replace instrument cluster lights (half of them dead, let's make them red). Will post results. Last thing, 30mm socket over it or straight piece of wood to hammer it in? Tried the socket, held it square and messed it up, so wondering (over thinking mode on full power) should I change the approach or just whack it straight in with a sledge (rubber, kidding... ).

Click to expand...

I used socket - if the old one is not mashed in getting it out you could use that as a drift too.

Right, job done. Here's some pics that I couldn't get through last time for some reason. One thing I have to say - I was surprised, tried melting the window, tried drilling and on tap it turned out to be just glass, not perspex - bought it from Motorworks, had only four holes on the back as oppose to eight as original directly from BMW dealer and as it was before on the bike. Wondering if this was the reason for the problem? Anyway, used a smear of RTV, this one just slipped in almost all the way in, tapped it in using a socket, it does seem to have some 'lips', but it's only around the 'grooves' in the front rubber part - seems oil tight on the first run, will ride it for a while today and see if it is sealed, but should be ok. Fingers crossed. I've also done transmission and final drive oil change with posh new straight-from-the-stealers crush washers and finally done the plugs, I have to say, I'm glad I've done that, see the last photo... On second photo you can see some damage (bent pipe) inside the engine passed the sightglass, I don't think I've done it as I've used seal puller and at any point it wasn't sticking into the hole to do that, seems like someone punched a screwdriver through the last time it was done, or was levering it out and caused damage... I'm hoping it shouldn't kill it, there is no weak spot, but technically it restricts the flow... We'll see.

On the other hand, Beemer annoyed me a bit, as I was trying to do alternator belt at the same time, but two bolts on the left side (looking from the front) came out fine, two on the right - heads corroded beyond a point I'd expect of a German quality and are rounded inside the hex bit, rendering them impossible / hard to retract, hence alternator belt is still squeaky and in need of replacement. Annoyed is the word. Same thing happened when I was trying to undo two bolts under tank to install original crash bars that I've bought. Head snapped on the first attempt, despite being soaked in WD40 for last few days prior to removal attempt. Here comes the drill, but as said, wouldn't expect such problems from such brand... Corrosion seems to be a big thing on them. I've Hammerite'd the stands and torque arm as all were corroded, will need to strip them off the bike, shot blast them and paint / powder coat them, providing I'm still not parted with it considering amount of grief and annoyance I've had off it so far... Someone didn't look after it, being the culprit but I haven't got as much time to take every simple task as next challenge every time, enthusiasm wearing off slowly. Photos:

Old sight glass (one I replaced and was leaking, notice four holes - this was actual glass).




Here's the bent pipe inside




And that's the new sightglass installed (BMW dealer part)




That's the odd sightglass (Motorworks) - shattered glass - careful with your eyes, I've hit it with a punch and it sprinkled a myriad of glass pieces all over the place, notice cracked rubber on the second photo - there were two cracks like that around the ring




And here's the photo of plugs as they came out - I think the service was due...

plugs a good colour though

Just to add - done around 30 miles yesterday and no signs of leaks. Phew....



This leak is something I've missed originally as I thought it was oil coming out of the sight glass. Not massive, but needs to be addressed.



And finally - quick question - only now I've noticed that the oil light won't come on, mind you, noticed that on a warm bike, not sure how long it should stay on for after engine is off - would that be oil pressure sensor? I take it it's the sensor on the right with cable attached to it on the first photo - up and right from the sight glass? Any other ideas? Changed the bulb to be on the safe side but still nothing. That worries / annoys me. It's like on the beetle, you've had oil and generator lights, only two but they were the two most important ones on an air / oil cooled boxer... Oil temp gauge works fine though.

change the sensor and yes it is oil pressure switch easy to change done mine on the r1150gs. how many miles your bike done ?

96045 just had a full service, unfortunately, probably first time in the last few years. Getting there though...

If the Oil Light does not come on at Ignition On then, if you earth the lead going to the Oil Pressure switch the Oil Light should illuminate thus indicating a faulty switch.