Front brake hose bolt washer dimension

[duxing]

I damaged the front brake hose bolt washer (hose to caliper) when working on a host replacement job for my 2021 model Y performance and I'm trying to get a fitting washer from local auto parts store to avoid buying a whole new assembly.


however, I'm not able to figure out the exact the dimension of the washer, and the OEM washer that I took off is badly damaged to provide an accurate measurement.

I'm wondering if folks here happen to know the dimension of those washers. Many thanks in advance!!

 

[mongo]

I damaged the front brake hose bolt washer (hose to caliper) when working on a host replacement job for my 2021 model Y performance and I'm trying to get a fitting washer from local auto parts store to avoid buying a whole new assembly.


however, I'm not able to figure out the exact the dimension of the washer, and the OEM washer that I took off is badly damaged to provide an accurate measurement.

I'm wondering if folks here happen to know the dimension of those washers. Many thanks in advance!!

Maybe M10 domed

Reference torque spec. I decided on these spec after referencing BMW and MINI service manuals I have available. *Use it at your discretion and risk*

25lb/ft - M10 Banjo bolt to caliper F/R (the copper washers are domed, so it will require almost a full turn of wrench after the first contact to reach torque)
10lb/ft - M10 brake line connector to hard brake line

Note: Do NOT use CRC green can brake cleaner, it will destroy the red paint on P3 caliper. O'Reilly is safe to use, didn't damage the paint of my stock P3 nor RB caliper.

 

[Goobers]

I damaged the front brake hose bolt washer (hose to caliper) when working on a host replacement job for my 2021 model Y performance and I'm trying to get a fitting washer from local auto parts store to avoid buying a whole new assembly.


however, I'm not able to figure out the exact the dimension of the washer, and the OEM washer that I took off is badly damaged to provide an accurate measurement.

I'm wondering if folks here happen to know the dimension of those washers. Many thanks in advance!!

Sure, you’d lose some brake fluid, but you could take off the other side. Then take the part with you to the shop.

 

[duxing]

Thank @Goobers @mongo for the suggestion.

I thought about this as a last-resort plan if trying available ones from local autozone don't work.

I end up trying all the options from a local autozone and found out that although the inner and outer diameters are standard but the thickness isn't. I guess I'd have to buy a new assembly instead.

 

[mongo]

Thank @Goobers @mongo for the suggestion.

I thought about this as a last-resort plan if trying available ones from local autozone don't work.

I end up trying all the options from a local autozone and found out that although the inner and outer diameters are standard but the thickness isn't. I guess I'd have to buy a new assembly instead.

As long as the bolt doesn't bottom out, thickness shouldn't matter... AFAIK
Both original washers from that bolt are destroyed?

 

[Goobers]

Thank @Goobers @mongo for the suggestion.

I thought about this as a last-resort plan if trying available ones from local autozone don't work.

I end up trying all the options from a local autozone and found out that although the inner and outer diameters are standard but the thickness isn't. I guess I'd have to buy a new assembly instead.

I can’t imagine there isn’t a washer with a close enough thickness to make it work. It’s not like you have to jump whole inches or something.

Edit: If I’m not mistaken, it should be a crush washer. So you should be looking for a crush washer that’s slightly thicker. Then you need to check for the torque spec.

 

[duxing]

I can’t imagine there isn’t a washer with a close enough thickness to make it work. It’s not like you have to jump whole inches or something.

Edit: If I’m not mistaken, it should be a crush washer. So you should be looking for a crush washer that’s slightly thicker. Then you need to check for the torque spec.

yeah you're absolutely right. unfortunately in my area the auto parts store only carries 3 options for these crush washers and out of those only 1 fit the inner and outer diameter (but much thicker)

given the effort, it may be easier to order the whole assembly. the torque is 31lbft from the service manual

 

[duxing]

As long as the bolt doesn't bottom out, thickness shouldn't matter... AFAIK
Both original washers from that bolt are destroyed?

only one of them is torn apart.
if the thickness doesn't matter I can give it a try. my concern is the extra thickness will affect the alignment of the hole for brake fluid between the hose and the banjo bolt

 

[mongo]

only one of them is torn apart.
if the thickness doesn't matter I can give it a try. my concern is the extra thickness will affect the alignment of the hole for brake fluid between the hose and the banjo bolt

If you are concerned, reusing the good one under the bolt head should retain that alignment.

 

[Goobers]

only one of them is torn apart.
if the thickness doesn't matter I can give it a try. my concern is the extra thickness will affect the alignment of the hole for brake fluid between the hose and the banjo bolt

The banjo bolt and ring(?) should basically form a channel that goes all the way around, so it shouldn’t matter.

https://upload.wikimedia.org/wikipedia/commons/b/b1/Banjo_Fitting_Schematic3.jpg

 

[Iron]

Tesla Model Y 20-22 Hose Assy Front Brake Left Driver Side 1188721-00-B NEW OEM | eBay

â Tesla Model Y 2020-2022 Hose Assy Front Brake Left Driver Side â. Part Number: 1188721-00-B OEM. Condition is New.

www.ebay.com

The whole assembly is $70 on eBay. Not sure which side you damaged, but I'd buy that side even if the washers are the same. What caused you to mess with that hose in the first place?

Here is an assortment pack on Amazon.

https://www.amazon.com/gp/aw/d/B0BHY3FGVG/ref=ox_sc_act_image_1?smid=A1ORHTP7CIIYZC&psc=1

 

[duxing]

@mongo @Goobers Thank you both! you're right about if the top ring is reused the alignment should be fine.

I'll try the washer I got and see if it works

@Iron the OEM bottom crush washer was too tightly coupled with the banjo bolt and in trying to remove it I damaged it.

 

[duxing]

got response from Tesla:
1. the specification for the washer is not provided and probably won't be
2. buying the assembly from Tesla is $25 => probably not worth looking into other alternatives