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Front brake calipers

A

alke46

Member
on my 2001 R11000RL. I'm reading through the Clymer manual and it states that the front calipers should not be separated. Why is this? And what could go wrong if they are taken apart?

Are they sealed somehow and would possibly leak if taken apart? Just what is the deal with why they should not be taken apart?

TIA
 
Seems there is a seal issue. The last of the threads in the Similar Threads pane suggests that.
 
alke4346 said:
on my 2001 R11000RL. I'm reading through the Clymer manual and it states that the front calipers should not be separated. Why is this? And what could go wrong if they are taken apart?

Are they sealed somehow and would possibly leak if taken apart? Just what is the deal with why they should not be taken apart?

TIA
Click to expand...

You risk them leaking when you reassemble.

Question: Why do you want to split them?
 
The real question is why do you want to take them apart. There is no earthly reason to do so.

Can you find an official torque figure for putting them back together?

Can you find new bolts ... it's likely the old ones shouldn't be reused.

Your job as a mechanic is not to demonstrate that you know more than engineer designers, it is instead to follow their directions. Several airplanes have crashed following "creative" work by "mechanics" without engineering knowledge.
 
I wanted to split them so I could give them a really good cleaning and look for any crud that has built up over the last 10+ years of not being properly taken care of.

I wanted to be able to remove the piston and dust seals to be able to make sure of their cleanliness.
 
alke4346 said:
I wanted to split them so I could give them a really good cleaning and look for any crud that has built up over the last 10+ years of not being properly taken care of.

I wanted to be able to remove the piston and dust seals to be able to make sure of their cleanliness.
Click to expand...

You can do all of that without splitting the calipers.
 
I split mine before I had read that you should not. I had to rebuild the calipers, master cylinder, and new lines for a brake issue. you can find replacement for the small gasket that is at the hole that connects the 2 halves however the big problem is getting the 2 halves back together flush and true. I reused the bolts and everything worked out fine. I would NOT do that knowing everything now and for what its worth Brembo would tell you not to do it. you want to be careful with how much and the way you tighten them, you want to make sure you do not cause it be misaligned.
 
The seals (O ring) are hard to source. Some Brembo sellers do stock them.

No need to split them.
Remove the pistons and seals, bleed screw
Wash everything in hot soapy water (dish soap), scrub with an old toothbrush.
Rinse in hot water, blow dry with compressed air including all passages.
Reassemble with Red rubber grease or DOT 4 fluid.
 
They are normal O rings
If they match the original dimensions and are compatible with brake fluid you are good to go.
 
jagarra said:
Here is a source for metric o-rings, if possible use viton material that is made for harsh environments.
https://www.rocketseals.com/Metric-...KIuc5PHMJ4nFbKRJXHb4ijbBoEVPT3_RoCtvYQAvD_BwE
Click to expand...

I’m not finding a chart or other documentation showing Viton as being compatible with DOT3/DOT4 brake fluid. EPDM is the rubber compound most commonly used for seals and o rings that contact brake fluid. If you have documentation showing Viton compatibility please share that—there are more sizes and options in Viton than in EPDM with the vendors I’ve researched.

Thx,
DeVern
 
alke4346 said:
Are these o-rings anything special? I ask because there is this, www.theoringstore.com.
Click to expand...

I just ordered several sizes that looked like they would work and used one that appeared the same size as the one i lost when splitting them. the other I cleaned and reused worked for thousands of miles with no issue. I have got rid of the bike because i liked to ride more than repairing and doing maintenance on a 20 plus year old bike. Had the bike had more value and was worth dong all new suspension and a better seat I would still have it.
 
lkchris said:
The real question is why do you want to take them apart. There is no earthly reason to do so.

Can you find an official torque figure for putting them back together?

Can you find new bolts ... it's likely the old ones shouldn't be reused.

Your job as a mechanic is not to demonstrate that you know more than engineer designers, it is instead to follow their directions. Several airplanes have crashed following "creative" work by "mechanics" without engineering knowledge.
Click to expand...


Seems a little over the top to me. Don't you ever do any of your own mechanical duties? And just how would you address the issue I have in the attached photo? New one obviously on the right side, partially disintegrated one on the left is what came out upon splitting open the two caliper halves.

BTW, the second caliper o-ring was even worse.

IMG_20220924_135802729 by Larry Alkire, on Flickr
 
alke4346 said:
[/U][/I][/B]
New one obviously on the right side, partially disintegrated one on the left is what came out upon splitting open the two caliper halves.

BTW, the second caliper o-ring was even worse.

IMG_20220924_135802729 by Larry Alkire, on Flickr
Click to expand...

Brake fluid really is nasty stuff.

My opinion is a little different than the other folks in this thread, and that O-ring on the left is why. I think any and every rubber part that touches brake fluid should be replaced after a while -- especially on a brake caliper that's probably been in continuous contact with brake fluid for 20+ years. EPDM is resistant but not impervious. Splitting the calipers is necessary to get to those rings and, like you, it's what I'll be doing when I rebuild my own.

There's an Ebay seller of brake parts in England called Powerhouse-UK, and their full rebuild kits for our brake calipers are about $100 shipped to the US. They include the pair of O-rings for sealing the caliper halves.
 
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