K100RS parked for four months outside in all weathers

[Filmcamera]

Today I begin re-installing the ABS on the bike.  I have been looking on the internet and in this forum but I am a little hazy on one thing.  As far as I can tell on the modulators, ABS I, the top hole is for the line coming from the brake lever, either hand or foot, and the bottom one is for the line going to the caliper.  Can anyone confirm that?

[Laitch]

Can anyone confirm that?

Have you looked at the diagram that's found if you scroll down here?

[Filmcamera]

Yes. I did, in fact that is the ONLY place I found a clue as to which goes where, I was just looking for confirmation from elsewhere.

[Laitch]

Yes. I did, in fact that is the ONLY place I found a clue as to which goes where, I was just looking for confirmation from elsewhere.

Go with it.

[The Mighty Gryphon]

Looking at the modulators on my K75S, the top fitting near the bleeder is the inlet from the master cylinder, and the lower connection goes to the caliper.

[Filmcamera]

Thanks MG



Now,  have a question about the three hard lines., Two long and one short.  As far as I can tell so far one of the two long lines one is shorter than the other and has a wider thread at one end.  I think this is the line that goes from the modulator to the caliper. The other long line is therefore for the line to the brake lever.  The third short, curved one seems to be an extension for the line to the caliper.  I am having a little trouble working out the exact routing of the that pipe so I can connect it right. I have searched but can't find any photos on line.  Can anyone tell me how I should route the lines?  Thanks

[The Mighty Gryphon]

Does this help? 

[Filmcamera]

hmm kind of - though it seems to reverse the previous decision that the top line was for the line to the brake lever and the bottom line to the caliper...

[Laitch]

Does this help?

It is a cause of confusion because it varies from the BMW ABS I Users Manual regarding the positions of the lever lines and the caliper lines. What is its original source, Gryph?

If this were my bike, I'd follow the manual and fit the parts accordingly. Somebody here must be able to make a photo layout of the assembly to help move you forward, Filmcamera, if the manual isn't enough for you.

[The Mighty Gryphon]

It's the parts fiche for the bike he's working on.  It should show the basic relationship, as far as what connects to what, of the various lines he said he was having a problem identifying.  The lines he is working with are off my RS which is the same model as his. 

The two long ones run to the modulator.  The one with the hose and the hard line goes from the master cylinder to one of the long lines.  The hose connects to the master cylinder, and the hard line connects to the long line that has the matching fitting.  The long line that connected to the hard line from the master cylinder goes to the inlet of the modulator.  The other line connects to the modulator outlet and is connected by a hose(not provided) to the fitting on the fork brace between the fork tubes.

As near as I can remember the two long lines run from somewhere above the right hand side of the radiator, back above the air box to the modulator.

[Laitch]

It's the parts fiche for the bike he's working on.

The two long ones run to the modulator.  The one with the hose and the hard line goes from the master cylinder to one of the long lines.  The hose connects to the master cylinder, and the hard line connects to the long line that has the matching fitting.  The long line that connected to the hard line from the master cylinder goes to the inlet of the modulator.  The other line connects to the modulator outlet and is connected by a hose(not provided) to the fitting on the fork brace between the fork tubes.

In the fiche diagram you supplied and your description from memory, that would make their positions reversed from the manual's schematic drawing as I understand it.

I'm slightly disturbed that although my safety is compromised by not having this ABS system on my bike, I'm happy about that—classic approach-avoidance.
 :yippee:

[The Mighty Gryphon]

On my K75's the rear brake modulator is connected as follows:

Upper fitting goes to the master cylinder and the lower goes to the caliper.   

The connections for the front modulator are configured differently from the rear modulator.   In that case I would follow the manual or the fiche illustration in lieu of better documentation.  I suppose it was a screw up to assume that the internal passages of the two modulators were the same even though the line connections were in different locations. 

I guess that Filmcamera will have to sort this out on his own.  The more I post the more confusing this gets.

[Filmcamera]

Yes the rear is easy, even the Clymer's specifies which line in the intake and which the outlet but it doesn't for the front modulator.  It also seems they changed the early ABS system's all the time.. For example my modulator has clearly different sized holes for the intake and outlet (as does the shorter of the two long hard lines I got from Gryph) yet the other one I have (which had the wires cut) has the same size holes. All I really need to know is if the top hole is intake or outlet, the rest I can work out from there.

[Filmcamera]

Today I finally got round to doing a compression test.  I freely admit I have been putting it off because I wasn't sure I would want to see the results.  In the end however it wasn't too bad.  it was a cold test since the tank is still at the painters.  Cylinders 1, 2 and 4 all read 120 psi and number 3 was 130 psi.  For a bike with 123,000 miles on it I was pretty pleased, especially since I have no idea of that state of the valves, again trepidation winning out there, especially as it is a 4V and they generally seem to have less issues than the 2 V K's.

[Martin]

Cylinder compression nice and even within 10 Psi, some compression gauges can read high or low. I would not worry until you have some miles it's belt. As stated numerous times Bricks do not like being idle and benefit from being used.
Regards Martin.

[Filmcamera]

I had another weekend of two steps forward one step back...


One Friday I did finally get the parts back from the powder coat - take two steps forward...


I got them home and discovered they had ignored everything I said and powdercoated the brake calipers completely.  That meant powder coat on the insides where the two halves are supposed to meet - that meant powder coat on the banjo bolts and bleed nipples they couldn't be bothered to remove, that means lost o-rings - oh and btw the way they 'misplaced'  all the brake pads and mounting hardware but are sure they will turn up.


Take four steps back.


Much sanding and cursing later the brakes calipers look ok, though I am super concerned about how much powder and crap has go into the system - I am going to be bleeding these three or four times at least before I try actually using them in anger.


Take one small tentative step forward.


I was able to FINALLY replace the fork seals and rebuild the forks.


Take a big satisfied step forward.


I then set to work with my tap and die set and have managed to clean up all the threads that got powder coated so I have been able to totally rebuild the front end and the rear brake and install the foot pegs mounts and rear wheel.


Two steps forward.


Of course the front wheel bearings got powder coated and I cannot get them out...


One step back.


Phew after what feels like a square dance I guess some progress has been made


In theory I get the tank and the rest of the painted parts this week.


I had one question about the rear wheel.  I know they came with four and five bolts.  I have five - on ebay I had got hold of a hub cap but it turns out it is meant for a four bolt wheel - it doesn't fit with my five bolt set up. How big a deal is it if I leave the fifth middle bolt out so I can use the hub cap?

[The Dude]

"How big a deal"?
I'm a bit confused about the fith bolt being in the middle...(Disclaimer)

I believe I'm far enough away to avoid litigation.4 bolts is ample for all the stresses involved....actually one would be enough not if it's the one in the middle though but don't quote me. :yow
(Disclaimer)Best sort it out properly.The inspector may take the cap off?
  The powder coated in wheel bearings,just scratch out the offending film on the wheel housing,carefully, and bash them out with a drift (solid bar)?and well aimed brute force.
Square dancing is par for the course.You will do better next time...won't you?

[Laitch]

I know they came with four and five bolts.

The five bolt configuration is news to me too. What's your source for that info?

[Filmcamera]

Well apart from the fact there are five holes and my bike came with five bolts, the Clymer shows five bolts for the three spoke wheel - in chapter 14 - supplemental info on 1990 and later models - the only part of clymer that seems to be right for my bike most of the time.

[Laitch]

Well apart from the fact there are five holes and my bike came with five bolts, the Clymer shows five bolts for the three spoke wheel - in chapter 14 - supplemental info on 1990 and later models - the only part of clymer that seems to be right for my bike most of the time.

Well, the fact that your front wheel came with its spoke orientation reversed doesn't make your bike's appearance a particularly sound reference for how things should be, does it? If the wheel calls for five bolts, it ought to have five bolts holding it; otherwise, you're heading down the maintenance path of the previous owner.


I questioned you because there's no reference in MAXBMW's fiche from a 5-bolt patterned wheel. Onward!

[Filmcamera]

I agree 100% that what ever is on my bike is not a great guide but it is in the Clymer ad the reason I though of asking was that in one of Chris Harris' videos he mentions them in passing with a disparaging remark.

[Martin]

Is the five bolt pattern counting the one in the centre as shown in your picture. I have a 92 K75S with 3 spoke wheels and it does not have the centre bolt. Does this centre bolt actually retain the wheel?   :dunno  I have looked at a Haynes manual and a few parts sites and can not see any reference to it I will continue to look it is a bit of a mystery.
Regards Martin

[Filmcamera]

Brute force did eventually win against the powder coated bearings but it needed a little bit of grey matter to do it.  There is very little lip inside to hit on and I was going nowhere fast, until inspiration struck.  The problem was I couldn't get any purchase and using a bigger drift (old screwdriver) made it worse not better.  What did the trick in the end was using my longest wrench extension with an old 16 mm socket on it.  That allowed me to maximise the purchase on the bearing by following the curve of the available lip with the curve of the socket.  A few sharp smacks and it was out!

[Filmcamera]

Martin yes it is in the center and it does seem to play a small part in retaining the wheel.


Here are excerpts from my Clymer page 616

[Martin]

Must pertain only to a couple of models. I would not do away with it, must be there for a reason for fitting it. As for the hub cap you should be able to find one that fits with a bit of hunting. The one from a K75 will not fit due to the centre bolt, one of the inmates might have one.
Regards Martin.