Question - front caliper seal replacement

[billy10]

2008 1200GS. Front brakes need to be fixed or replaced as some of the pistons are very sluggish. Question is whether strip, clean, and seal/piston replace is worthwhile vs purchase of new/used item. Has anyone done this to calipers with seal seat corrosion and had a good result 18 mths - 2 yrs down the line? (Versus corrosion returning worse than before). Thanks

 

[UturnTony]

Pop the pistons out and carefully remove each dirt seal in turn, thoroughly clean out it's groove taking out any build up of corrosion. Refit seal, first cleaning it and dipping in brake fluid. After this have a look at the fluid (lower ones) seals leaving them in the caliper. If they are in undamaged condition leave well alone just clean everything up before refitting the pistons (lube with brake fluid first) ensuring they go in square or they will jam and Bob's your uncle the job should be a guddun. This procedure has always resulted in a nicely operating brake caliper for me. Others I guess will insist you replace everything, something I have never found necessary.

Edit: Just noticed the returning corrosion comment. I have never found that to be the case; the calipers continued to operate nicely until i parted with the bike.

 

[billy10]

Thanks. I know how to do it. Am just asking about the extent to which a rebuild results in a long-term fix to this issue on these calipers - (Brembo Evos on the 08)

 

[UturnTony]

Thanks. I know how to do it. Am just asking about the extent to which a rebuild results in a long-term fix to this issue on these calipers - (Brembo Evos on the 08)

Apologies if the reply was too in depth.

Tbh. I supposed that if you needed to ask the question you weren't too familiar with the job of caliper refurbing.

 

[billy10]

Always amazed at how people behave on the internet

Very experienced local independent mechanic who used to work for BMW told me not to rebuild as these calipers are notorious for the corrosion returning worse than before. He says that they won't rebuild this caliper anymore as they've had so many problems. He advised me to buy decent second hand pair as it's a better long term fix.

I thought I would ask on the forum as the quality of feedback seems to have been quite high so far. If someone has had bad corrosion, rebuilt, and they work well years later, then that would be good to know.

When interactions are anonymous it is easy to be rude. But it's worth pausing to think before posting

 

[UturnTony]

Always amazed at how people behave on the internet

Very experienced local independent mechanic who used to work for BMW told me not to rebuild as these calipers are notorious for the corrosion returning worse than before. He says that they won't rebuild this caliper anymore as they've had so many problems. He advised me to buy decent second hand pair as it's a better long term fix.

I thought I would ask on the forum as the quality of feedback seems to have been quite high so far. If someone has had bad corrosion, rebuilt, and they work well years later, then that would be good to know.

When interactions are anonymous it is easy to be rude. But it's worth pausing to think before posting

Hang on a sec. I answered your question in more depth than you required which i apologised for then went on to say that as you
asked the question i assumed you weren't too familiar with the job which is why you got a verbose reply. Now you say i'm being rude
You'll not like it around here for too long if you think that was being rude by the way.

Anyhow, as you already had the answer to your question from a "very experienced independant mechanic" who told you to ditch the
calipers i can't understand why you felt the need to ask on here, a motorcycle forum tbh. and, as you aren't a subscriber any advice
you do get is got for free and given in good faith.

I'll leave you in peace to seek the answers you require

 

[autogs]

Hang on a sec. I answered your question in more depth than you required which i apologised for then went on to say that as you
asked the question i assumed you weren't too familiar with the job which is why you got a verbose reply. Now you say i'm being rude
You'll not like it around here for too long if you think that was being rude by the way.

Anyhow, as you already had the answer to your question from a "very experienced independant mechanic" who told you to ditch the
calipers i can't understand why you felt the need to ask on here, a motorcycle forum tbh. and, as you aren't a subscriber any advice
you do get is got for free and given in good faith.

I'll leave you in peace to seek the answers you require

nail head etc

 

[billy10]

Had to go to local BMW dealer today for a car part. Bumped into the bike mechanic who put my bike together when I bought it in 2008 (at a diff dealer where he used to work). Took the opportunity to ask him about the issue and think I have gotten to the bottom of it. There is a good reason I was told not to rebuild, although it is also possible to rebuild subject to certain caveats.

 

[Bendy toy]

My front brakes were rebuilt as soon as they began to feel sluggish.
All seals removed, cleaned and replaced. Seal grooves cleaned and greased with red rubber grease. No brake fluid used.
They have remained good. However the anodised layer was undamaged and red grease does not attract moisture like brake fluid does. so there is no reason for corrosion to be a problem.
I had the same experience with Yamaha “blue spot” calipers which are also anodised.
Bikes with bare alloy calipers however need a strip down every year and will often need new seals as well.
BMW charge £60 per caliper for the front brakes seals though to be fair they do include 4 phenolic pistons. Rears are £20 for seals only.

 

[AberdeenAngus]

Always amazed at how people behave on the internet

Very experienced local independent mechanic who used to work for BMW told me not to rebuild as these calipers are notorious for the corrosion returning worse than before. He says that they won't rebuild this caliper anymore as they've had so many problems. He advised me to buy decent second hand pair as it's a better long term fix.

I thought I would ask on the forum as the quality of feedback seems to have been quite high so far. If someone has had bad corrosion, rebuilt, and they work well years later, then that would be good to know.

When interactions are anonymous it is easy to be rude. But it's worth pausing to think before posting

Tony's reply was perfectly reasonable. Bloody excellent advice considering it was free. Wind your neck in.

 

[billy10]

Well that's not my view. I responded quite reaosnably to a post I thought unnecessary. I don't know who you are or why you think it appropriate to get involved and to be even ruder. As I wrote above, I am continually surprised by the manner in which people behave. Perhaps that is naive on my part.

In terms of free advice, telling me something I already know, which I hadn't asked, and which, for what it's worth, is not the optimum advice for that job, is not of much value to me. What was of use was to find out the problems with these calipers and the reason that some mechanics won't rebuild them. However, that came from the head technican at a nearby BMW dealer.

Under normal circumstances I would share as I am sure it would be of use to others given there are issues with these calipers - for example, as I am sure you know, Motorworks advise heavily against splitting them and are reluctant to sell the o-ring kit.

 

[andeebee]

I would of liked to have given some advice, having an 08 GSA with bad calipers, but I dont want to get involved.

 

[UturnTony]

Well that's not my view. I responded quite reaosnably to a post I thought unnecessary. I don't know who you are or why you think it appropriate to get involved and to be even ruder. As I wrote above, I am continually surprised by the manner in which people behave. Perhaps that is naive on my part.

In terms of free advice, telling me something I already know, which I hadn't asked, and which, for what it's worth, is not the optimum advice for that job, is not of much value to me. What was of use was to find out the problems with these calipers and the reason that some mechanics won't rebuild them. However, that came from the head technican at a nearby BMW dealer.

Under normal circumstances I would share as I am sure it would be of use to others given there are issues with these calipers - for example, as I am sure you know, Motorworks advise heavily against splitting them and are reluctant to sell the o-ring kit.

I'm out of this thread really but need to say this, i never mentioned splitting the calipers and i never do, i do the work with them in one piece and always have. Bendy, i'm talking a minimum lube with brake fluid just to help them slip into place. Hardly a moisture magnet. Anyhow, as i said i'm out and the OP can please himself what he does.

 

[Mac One]

Well that's not my view. I responded quite reaosnably to a post I thought unnecessary. I don't know who you are or why you think it appropriate to get involved and to be even ruder. As I wrote above, I am continually surprised by the manner in which people behave. Perhaps that is naive on my part.

In terms of free advice, telling me something I already know, which I hadn't asked, and which, for what it's worth, is not the optimum advice for that job, is not of much value to me. What was of use was to find out the problems with these calipers and the reason that some mechanics won't rebuild them. However, that came from the head technican at a nearby BMW dealer.

Under normal circumstances I would share as I am sure it would be of use to others given there are issues with these calipers - for example, as I am sure you know, Motorworks advise heavily against splitting them and are reluctant to sell the o-ring kit.

I think you're well out of order, someone takes the time to try and help you and you come away with all that don't waste my time guff. If you don't like the advice, ignore it.

 

[dean0n0]

A BMW tech hasn't got a vested interest in selling a new calliper rather than spend time servicing the old one......

 

[Bendy toy]

I'm out of this thread really but need to say this, i never mentioned splitting the calipers and i never do, i do the work with them in one piece and always have. Bendy, i'm talking a minimum lube with brake fluid just to help them slip into place. Hardly a moisture magnet. Anyhow, as i said i'm out and the OP can please himself what he does.

Fair comment TBH.

My last bike's OEM calliper seals grooves corroded badly as they were bare aluminium. The replacement Blue Spots being anodised were much better as are the BMW/Brembos. I used the red grease in an attempt to reduce seal seat corrosion. It worked better than clean brake fluid alone but TBH that was not saying much.

 

[Bendy toy]

A pair of calipers on eBay will cost around £100, but you will be taking chance on the state of seals and pistons. Later models have the phenolic resin pistons but that's no certainty of success.