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Crashed. I thought I escaped unscathed but turns out I broke the plastic lid and from a vintage bike there's no one selling the entire combi levers or just the lid itself. (in shops locally, I saw on ebay but with shipping, it aint worth the cost) It's on a 3x9 speed XC bike with XT parts ..

friends are egging me on for a 10 spd upgrade but I am not ready to shell out more cash on a 2 week old (2nd hand bike)

what do you guys think I should do?

fyi my combi levers look like this http://www.ebay.com/itm/VINTAGE-SHIMANO-DEORE-XT-9x3-BICYCLE-SHIFTERS-HYDRAULIC-BRAKE-LEVERS-M765-/151247697679

enter image description here

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    It sounds like its an aesthetic part - just put some duct tape over the area and get on with your life. – Batman May 8 '14 at 2:36
  • Most plastics can be effectively glued, if you find the right glue. And, of course, for a brake reservoir cover, you'd have to thoroughly wash the part before gluing. – Daniel R Hicks May 8 '14 at 12:16
  • The way I read it, it sounded like a plastic piece which went over the reservoir to make the setup look nice. – Batman May 8 '14 at 14:54
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    The Shimano part numbers for the replacement are Y-6JK 98080 (for left hand lever) and Y-6JK 98090 (for right hand unit), which I found from the ST-M765 exploded view. If you search for these codes, you might be able to find a shop that stocks the part, or you could ask your LBS to order it from Shimano. However, since the parts are a bit old now, the spares may no longer be available direct, and only from retailers who have old stock remaining. – jbuk May 8 '14 at 14:57
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    @Batman, yeah, so long as it's just the top piece in the diagram then it appears to be cosmetic, although with it removed the screws might bottom out in their holes in the reservoir body. However, you could just buy some shorter M3 machine screws if that turns out to be an issue. – jbuk May 8 '14 at 15:00
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If you have only broken the upper part, which I have marked A on the exploded view diagram, then I don't think that serves a functional purpose other than making the brake levers look nicer. Therefore, you should be able to continue to use the levers so long as part B is in place, but without the added thickness of part A, the screws (part C) may be too long to fit in the threaded holes in the lever body. Shimano lists these as being 'M3 x 8', and they appear to be Phillips pan-head machine screws. You'd want to buy some M3 x 6mm machine screws to replace them and be sure of not bottoming out the screws.

ST-M765 exploded view excerpt

Alternatively, Shimano make available the entire reservoir cover assembly, (26) on the diagram, under the part numbers Y-6JK 98080 for the right-hand assembly and Y-6JK 98090 for the left hand assembly. You may be able to find an online stockist of these spares, or possibly ask your LBS to order them from Shimano. However, as M760 series Deore XT is relatively old, it is unlikely that any spares will be available direct, and you'll have to hope that shops have the parts already in stock.

The full exploded view diagram is available at https://www.paul-lange.de/support/shimano/explosionszeichnungen_archiv/ST//ST-M765.PDF

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    That won’t work the plastic peice A is needed to support and squash down onto part B making a seal part B is like a very soft rubber I have tried taping my cap back on and using zip ties and that works but you will definitely need new caps or they will not work – Josh Dec 16 '19 at 19:23
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    part A does have a technical purpose: to clamp down on the rubber seal (part B) in order to keep the brake fluid in the reservoir. Part B will not seal the reservoir as long as part A is not pressing on it's edge. – Maarten -Monica for president Dec 16 '19 at 20:23
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The reservoir cover (part A) is not merely for aesthetics. (as mentioned by @Josh in his answer)

The reservoir cover's (part A in the drawing) purpose is to press down on the rubber reservoir seal (part B in the drawing). If the reservoir cover is broken it is not a problem as long as it remains stiff enough to properly press against the entire circumference of the rubber seal (part B). Depending on the damage you may be able to keep using the part, as long as the reservoir doesn't leak. enter image description here (Thank you for the image @jbuk, if you want me to remove it pls let me know) If however the damage is severe enough to cause a significant reduction in stiffness of the cover and you've tried gluing it and it didn't work you will have to replace it. The correct part numbers have been mentioned in the comments by @ jbuk; "part numbers for the replacement are Y-6JK 98080 (for left hand lever) and Y-6JK 98090 (for right hand unit)"-jbuk )

As suggested by @Daniel R Hicks in a comment you could try gluing the reservoir cover if the damage by the crash isn't too severe.

From the looks of part B and from my experience part B has a flat top surface meaning you could quite easily replicate part A (the reservoir cover) by taking a piece of plate material (wood, metal, plastic) of approximate size, drilling holes for the 2 screws that hold it in place and clamp the plate down to create the seal. If the plate thickness is adequate it should seal just as well as the original part. and it is very cheap to make. I would suggest using approx 3-4mm wood or 1.5-2mm steel/alu and 4-5mm plastic for material thicknesses.

For making the outline i would suggest using a jigsaw or power jigsaw (with very fine teeth) for plastic and wood and an iron saw if going with metals. For rounding the edges either use an angle grinder with flap disc or metal/wood file. It won't look perfect but it's a cheap solution.

I forgot to mention you'll have to countersink the screw holes on the bottom side of the plate in order to make room for the rods on the brake reservoir which hold the threads the reservoir cover screws screw into. In plastic/wood this is a relatively easy thing to do, in metal it might be a bit harder but still doable. Alternatively you could drill a through hole of the rod's diameter and use washers on the top to keep the cover properly clamped onto the rubber seal.

I'll add a drawing of the part below: Option 1: (countersunk hole) enter image description here Option 2: (through hole) enter image description here

Note: part (B) rubber seal is not shown in the 2 drawings above, but it will be located in between the red and grey part as can be seen in shimano's exploded view drawing

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