11 BMW 1983 R100RS Shim Oil Filter Canister, Install Oil Cooler & Filter

As part of this work, I check the depth of the oil filter canister and shim the oil filter canister for the correct compression of the “$2,000 O-ring”, so called because if it doesn’t seal, the engine doesn’t get oil and a new engine was about $2,000 back in 1983.

Resources

These are good references on the oil system, oil cooler, filters and filter covers BMW has used on the airhead motorcycles.

I use Oak Okleshen’s method for determining the number of shims to use, as described later.

Tools

This bike has the thermostatic controlled oil cooler. There is a special bolt (part# 11 42 1 335 394) that is screwed into the thermostat housing to open the oil cooler control valve to let oil fill the oil cooler. Since I drained the oil cooler, I use the tool when I crank the engine to pressure up the oil circuit so oil will fill the cooler. This is a precaution to prevent damage to the oil cooler if it should suddenly get pressurized while there is air in the oil cooler passages.

Special Oil Cooler Filling Bolt Is 23 mm Long

Special Oil Cooler Filling Bolt Is 23 mm Long

NOTE:
As Bob Fleischer points out in his articles, some of these bolts are too long and some don’t have the end rounded enough to avoid damage to the thermostat valve when you install it. The above bolt is correct.

I use a depth gauge and vernier caliper to make measurements of the oil filter canister depth.

Vernier Caliper and Depth Gauge

Vernier Caliper and Depth Gauge

And because I have grown to not “trust but verify”, I use a micrometer to confirm the shim and white o-ring thickness.

One Inch Micrometer

One Inch Micrometer

Parts

I install a new hinged filter, white o-ring, black square o-ring and the shims needed to ensure the white o-ring is compressed enough to seal the oil canister and the filter cover. The filter kit from Euro MotoElectrics includes the hinged filter, one shim, an oil filter cover gasket, the white and black o-rings and an oil drain plug gasket. Based on my measurements of the depth of the oil filter canister I do not need the gasket.

Video

Here is a short video summary of how I do this work.

VIDEO: 1983 BMW R100RS Shim Oil Filter Canister, Install Oil Cooler & Filter

Oil Cooler Operation

The oil filter cover contains a thermostat activated valve to allow more oil to flow through the cooler as the temperature goes up. The cover connects to hoses that go to the oil cooler which are secured by banjo bolts with a copper washer on each face of the bolt.

The oil filter is hinged and has a black grommet on one end. The grommet goes inside the filter canister against the back of the canister. The filter cover is installed with shims (at least one) that fits over the lip of the filter canister with a white o-ring on top of the shims against the cover

There is square profile black o-ring that fits in a groove in the filter cover to seal the center pipe that sends oil to the engine. The cover is secured to the engine block with three bolts with wave washers. I replace the stock hex-head bolts with Allen bolts since they are easier to remove in the tight quarters around the filter cover when I need to change the filter.

Thermostat-Oil Filter Cover Parts Detail

Thermostat-Oil Filter Cover Parts Detail

NOTE:
In the following paragraph, I use “left” and “right” from the perspective of facing the front of the bike rather than the traditional perspective of when you are sitting on the bike.

As shown in the picture below, there are two holes in the filter cover. The large center hole connects with the center pipe inside the filter canister that feeds filtered oil into the engine.  The smaller off-center hole connects to the right oil cooler hose (the one closest to the engine) to send oil to the cooler. The two holes in the cover are connected so if the thermostat is closed almost all the oil will go directly to the engine. As the oil temperature rises, more oil goes through the off-center hole to the cooler and returns via the left oil line (the one farthest from the engine) mixing the cooler oil returning from the cooler with the oil going into the center of the cover to the engine.

Thermostat-Oil Filter Cover Detail

Thermostat-Oil Filter Cover Detail

Measure Oil Canister Depth

I used both a depth micrometer and a depth gauge with vernier caliper to take measurements of the depth of the oil canister from the top of the engine block. I was curious how close the measurements are using these different methods. I found they agreed within 0.1 mm (0.004 inches), which for this purpose means the less costly depth gauge with vernier caliper is accurate enough.

I took four measurements at 12:00, 3:00, 6:00 and 9:00 around the circumference of the canister and averaged them to compute the depth of the canister. To take the measurements I put the depth gauge flush on the engine block and extend the rod until it touches the lip of the canister. I lock the rod with the set screw then transfer the length of the rod to the vernier caliper for an accurate measurement.

Depth Gauge Face Is Flat On Face Engine Block With Rod Against The Lip Of The Filter Canister

Depth Gauge Face Is Flat On Face Engine Block With Rod Against The Lip Of The Filter Canister

Transferring Depth Measurement From Depth Gauge To Vernier Caliper

Transferring Depth Measurement From Depth Gauge To Vernier Caliper

I take a “trust but verify” approach to the shims and white o-ring since sealing the oil filter cover and canister are critical to ensuring oil flow to the engine. I measure the thickness of the shims to confirm they are nominally 0.3 mm thick and the white o-ring to confirm it is nominally 4 mm thick.

Checking Shim Thickness With Micrometer

Checking Shim Thickness With Micrometer

Oak Okelshen’s Formula for White O-ring Compression

Oak Okelshen wrote an article in the Airhead newsletter, Airmail, on how to compute the compression of the white o-ring when using shims and the optional paper gasket. Mike Valenti sent me this information in a private Email.

Variables 
O“-> O-ring diameter = 4.0 mm (I measured this because I’m a skeptic)
S“-> Shim Thickness = 0.3 mm (I measured this as there nave been variations)
C“-> Cover Gasket Thickness = 0 mm (only used if canister is too high)
D“-> Distance From Top Of Canister To Engine Block
Equation 
[(O + SCD)/O ] * 100% => between 10% – 25%
NOTE:
The value of “C”, which is the thickness of the oil filter cover gasket, is zero if your canister depth is 3.0 mm or lower. Some canisters are too shallow and to avoid damage to the white o-ring from over compression, you will add a cover gasket. I’ve heard in some cases more than one cover gasket was needed to get the correct o-ring compression.

Spreadsheet Calculations For Number Of Shims

This is the spreadsheet I made to help determine how many shims I need. Based on my measurements, the canister on this bike is deeper than BMW’s specifications. According to Bob Fleischer’s information, this is not uncommon and is one reason you should measure your canister depth before deciding on the number of shims you need.

NOTE:
Bob’s material states that the filter canister depth can change over time so it’s a good idea to check the depth every time you replace the oil filter and keep a record of the canister depth. I believe mine receded about 0.2 mm since I got this bike which is almost the thickness of a shim.

Canister Shim Calculation Spreadsheet

Canister Shim Calculation Spreadsheet

This section is where I measure the depth of the canister at the four locations shown.

Spreadsheet Section For Depth Measurements

Spreadsheet Section For Depth Measurements

This section is where I enter the values for Oak’s formula and the nominal measurements I got for the shim and white o-ring thickness. I do not use a cover gasket since my canister is recessed more than BMW’s specified range for the canister depth.

Spreadsheet Section For Formula Values

Spreadsheet Section For Formula Values

This section computes the compression of the white o-ring as the number of shims increases. I want the o-ring compression to be between 10-25% of the original 4 mm thickness of the white o-ring (0.4 – 1.0 mm).

Spreadsheet Section With Computed Compression Percent For Different Numbers Of Shims

Spreadsheet Section With Computed Compression Percent For Different Numbers Of Shims

I decide to install three shims as my canister is recessed more that the BMW specification which compresses the white o-ring about 21%.

Clean Up And Mount Oil Cooler

The oil cooler mounts with a bracket to a frame tube under the steering head. I remove the bracket from the cooler and clean and polish it.

Oil Cooler Before Cleanup

Oil Cooler Before Cleanup

Oil Cooler Bracket Mounting Detail

Oil Cooler Bracket Mounting Detail

Oil Cooler Bracket Mounting Detail

Oil Cooler Bracket Mounting Detail

Cleaned Up Oil Cooler Bracket Hardware

Cleaned Up Oil Cooler Bracket Hardware

I removed the hoses on the oil cooler and cleaned up the fittings and the hoses and inspect the hoses for any cuts, nicks or signs of deterioration. Mine appear serviceable.

Oil Cooler Hose Before Cleanup

Oil Cooler Hose Before Cleanup

Oil Cooler Hose Before Cleanup

Oil Cooler Hose Before Cleanup

Cleaned Up Oil Cooler And Hoses

Cleaned Up Oil Cooler And Hoses

I attach the bracket to the top of the oil cooler so the cooler is facing in the correct direction. The sloped edge of the tab on the cooler the bolt goes through faces to the front of the bike. I temporarily attach the cleaned up oil cooler bracket to the frame tube under the steering head so I can adjust it when I install the oil cooler hoses to the thermostat-oil filter cover to eliminate any kinks or strain on the hoses.

Oil Cooler Bracket Hardware Detail

Oil Cooler Bracket Hardware Detail-Sloped Edge Of Cooler Tap Points Forward

Cleaned Up Oil Cooler Bracket Mounted To Cooler

Cleaned Up Oil Cooler Bracket Mounted To Cooler-Lower Face Of Cooler Points To Front

Oil Cooler Bracket Temporarily Mounted To Frame Tube

Oil Cooler Bracket Temporarily Mounted To Frame Tube

Right  Oil Cooler Hose (When Facing The Front Of The Bike) Has An Elbow Fitting

Right  Oil Cooler Hose (When Facing The Front Of The Bike) Has An Elbow Fitting

Left Oil Cooler Hose (When Facing The Front Of The Bike) Has A Straight Fitting

Left Oil Cooler Hose (When Facing The Front Of The Bike) Has A Straight Fitting

Cleaned Up Oil Cooler

Cleaned Up Oil Cooler And Hoses Loosely Mounted To Bottom Of Cooler

Install Oil Filter and Thermostat-Oil Filter Cover

I install the black square rubber gasket in the groove on the inside of the filter cover.

Black, Square O-Ring Fits In Groove In Thermostat-Oil Filter Cover

Black, Square O-Ring Fits In Groove In Thermostat-Oil Filter Cover

Square O-Ring Installed In Thermostat-Oil Filter Cover

Square O-Ring Installed In Thermostat-Oil Filter Cover

The hinged oil filter has a rubber grommet on one end that goes inside the filter canister against the back of the canister.

Filter Grommet Goes Inside The Canister Against The Engine Block

Filter Grommet Goes Inside The Canister Against The Engine Block

Outside End Of Filter Has No Grommet

Outside End Of Filter Has No Grommet

I need three shims to compress the white o-ring enough to seal the canister and cover. The shims fit over the edge of the canister.

NOTE:
I took these pictures before I installed the filter, but you should install the filter and then the shims.

I Need Three Shims But Your Canister May Not

I Need Three Shims But Your Canister May Not

Shims Fit On Top Of Canister

Shims Fit On Top Of Canister

The white o-ring goes on top of the shims. However, it’s easier to install it on the ridge on the inside of the filter cover which keeps it in place.

White O-Ring Seals Around Canister And Filter Cover

White O-Ring Seals Around Canister And Filter Cover

Easier To Install The White O-Ring When Its On The Shoulder Of The Filter Cover

Easier To Install The White O-Ring When Its On The Shoulder Of The Filter Cover

I attach the cover with the three Allen bolts and wave washers.

Easier To Use Allen Bolts And An Allen Key To Attach The Filter Cover

Easier To Use Allen Bolts And An Allen Key To Attach The Filter Cover

After I install the cover, I attach the banjo fittings on the end of the oil cooler hoses. I make sure the hose fittings on the bottom of the cooler are loose so the banjo fittings can rotate so the faces of the fittings will be flush with the mating surface on the thermostat-oil filter cover.

Oil Cooler Hose Banjo Fittings

Oil Cooler Hose Banjo Fittings

I attach each banjo fitting with a banjo bolt. I put a copper washer on the bolt head and a second washer between the banjo fitting and the mating surface of the thermostat-oil filter cover making a sandwich with the washers acting as bread and the banjo fitting as the filling. The banjo bolts are torqued to 13 FT-Lbs. Since this is a low value, I use my INCH-Lb wrench set to 156 INCH-Lbs. It’s a good idea to wait 24 hours and torque the banjo bolts again to the proper torque as they can loose as the copper washers compress.

WARNING:
If you over torque the banjo bolts you can shear them off, so always use a torque wrench. And use a socket wrench on them, not a crescent wrench.

Torque Oil Cooler Hose Banjo Bolts To 13 FT-Lbs, Or 156 INCH-Lbs

Torque Oil Cooler Hose Banjo Bolts To 13 FT-Lbs, Or 156 INCH-Lbs

Thermostat-Oil Filter Cover And Oil Cooler Hoses Attached

Thermostat-Oil Filter Cover And Oil Cooler Hoses Attached

I tighten the hose fittings on the bottom of the oil cooler. I move the cooler so it’s centered on the frame tube and the hoses are not kinked and then tighten the two bolts that secure the oil cooler bracket to the frame tube. I also make sure the hoses are not touching each other so they won’t rub together. When I install the fairing I may have to adjust the hose routing to be sure the hoses don’t touch the fairing panels either.

Cooler Hoses Installed So They Don't Rub On Each Other

Cooler Hoses Installed So They Don’t Rub On Each Other

Filling The Oil Cooler Safely

Since the oil cooler has been drained, its filled with air. Should the thermostat valve open suddenly, it could over pressure the cooler. And when the cooler fills, the oil level will drop in the oil pan. So I use a special bolt to force the thermostat valve open in preparation for my first engine start.

There is a bolt on the bottom of the thermostat-oil filter cover that I remove. The special bolt is 23 mm long and I thread it into the hole and snug it up.

Access Bolt Is Removed To Install Special Oil Cooler Filling Bolt

Access Bolt Is Removed To Install Special Oil Cooler Filling Bolt

Access Bolt Detail

Access Bolt Detail

Special Oil Cooler Filling Bolt Is 23 mm Long

Special Oil Cooler Filling Bolt Is 23 mm Long

Screw Special Bolt In To Open Thermostat All The Way

Screw Special Bolt In To Open Thermostat All The Way

Special Bolt Snugged Up

Special Bolt Snugged Up

To prime the oil cooler and all the oil passages in the engine, I remove the spark plugs and disconnect the GREENBlue coil power wire so the engine won’t start and optical-electronic ignition is not damaged. I remove the valve covers and crank the engine until the oil pressure light goes out and I see oil dribbling out of the top rocker assembly pillow blocks on top of the heads. The rocker pillow blocks are last in line in the oil system so when oil comes out of them it indicates all the oil passages are clear and the oil cooler has filled with oil. Then I check the oil level in the oil pan, add more oil as necessary, install the valve covers, remove the special thermostat bolt and install the original bolt, and attach the GREENBlue coil power wire to the right lower coil terminal before attempting the first engine start.

Revisions

2020-08-01  Cautions about oil cooler filler bolt, banjo bolt torque and routing hoses & cover gasket.

10 thoughts on “11 BMW 1983 R100RS Shim Oil Filter Canister, Install Oil Cooler & Filter

  1. There are probably some of the wrong (too long) oil cooler refill bolts still around…they must not be used. They can be modified for the proper 23 mm length… the end should be slightly rounded to avoid damaging the internals of the thermostat unit. There are two photos, next to each other, in my tools article, https://bmwmotorcycletech.info/tools.htm in item #30 in that article, about those proper and wrong bolts. I’ve seen proper length of these bolts that are not rounded and smoothed enough.
    I suggest avoiding having the ends of the hoses from the cooler touching each other, …and…more importantly …is that …on the BMW faired models, …the hoses should not end up being able to vibrate against the inside of the lower fairing. That vibration CAN..and has… loosened a banjo and allowed the oil to start weeping, then dripping, then disappearing from the engine at an increasing rate, as miles accumulates. A catastrophic engine failure will then follow.
    I recommend rechecking the tightness of the banjo bolts after an overnight sit, or at least a few hours…because the various fittings DO change size a bit after the first torquing, and they do this every time. Another Caution I think you might want to include: DO NOT use an open end wrench to tighten the banjo bolts. Any non-torque wrench tightening should be considered an emergency measure only….the banjo bolts WILL fracture if overtorqued.

  2. Brook. What is the suggested measurement of the center pipe relative to the cooler flange on the block. I.e. does it sit proud of the case some distance?

    • Hi James,

      IIRC, in one of Bob Fleischer’s documents I include a link to in the reference section, he mentions that distance, but I don’t remember it. Take a look there and I think you will see it.

      Best.
      Brook.

  3. This comment is meant to be sung to the tune of “You are my Sunshine”, from the movie “O Brother Where Art Thou”, and many other sources.

    Ahem.

    “Brook is my hero, my Beemer hero, he describes tech clearly, when things are gray. You’ll never know Brook, how much you help us, please don’t take your website away.”

    • Ran,

      Goodness, that’s quite the musical tribute, not to mention sharing company with a great movie and song. Thank you. 🙂

      Best.
      Brook.

  4. hi there – thanks for the excellent guide.
    I wondered a few things below, as I am fitting the same cooler to my bmw r100 engine.
    1 – I have heard changing the oil filter centre pipe is a bit of a bugger, did you have to do this?
    2 – Also how come you used the split oil filter, I dont see an issue with the top mounted radiator and the normal filter?
    3 – Did you check the hole size on the inlet, apparently this has to be drilled from 2mm to 4mm?
    4 – Did you check the thermostat was working off of the bike? If so, how?
    5 – Finally how you cleaned up the banjo’s etc. so well?
    Thanks so much,

    • Hi Alex,

      1. No
      2. They are stronger and there is not much clearance with the frame
      3. No. This is a stock oil filter installed at the factory, not a retrofit
      4. No. I checked when I did the first engine start after my 10 mile ride.
      5. Elbow grease and Autosol Metal Polish.

      Best.
      Brook.

      • Hi Brook,
        Thanks so much for your replies, on q4 have a look on snowbum / the web as there was a recall on the standard oil cooler return hole (but that might be the standard non thermostatic version)!
        Cheers and safe riding!
        Alex

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