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1Back to top Go down   Brakes bled but still spongy feel??? Empty Brakes bled but still spongy feel??? on Wed Jul 04, 2012 7:06 am

KJB

KJB
active member
active member
Hi guys,

Back again! My K100RS has a K1100 4 pot caliper conversion (done by a previous owner). Since taking ownership the master cylinder has always leaked so I have replaced it. The brake components had been taken to pieces/calipers stripped of paint/repainted and cleaned.

Since refitting everything I am having trouble bleeding the brakes and getting a 'hard feeling' on the front brake. I'm using a mityvac brake bleeder which is getting all the air out but still a spongy feel at the lever.

Is the combination of these non standard calipers a good idea? The brake pads are new by the way! New fluid too!

Any ideas???

Thanks Kim

    

2Back to top Go down   Brakes bled but still spongy feel??? Empty Re: Brakes bled but still spongy feel??? on Wed Jul 04, 2012 7:16 am

Inge K.

Inge K.
VIP
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By judging the picture you got a 13 mm master, the four pots use a 20 mm.
That could be some of the reason.
I think Rick have some experience with that combination.


__________________________________________________
Inge K.
K100RS -86. (first owner), K1100LTSE -94.
    

3Back to top Go down   Brakes bled but still spongy feel??? Empty Re: Brakes bled but still spongy feel??? on Wed Jul 04, 2012 8:50 am

RicK G

RicK G
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That was our GITH but I have heard that a 16mm of the very last of the airheads is a good master cylinder as the brakes come up well and with good feel but the 20mm one is the OEM.
Go over your brake lines to make sure none are expanding or getting big bubbles in the outer sheath. Also if you can use the stainless braided lines they are really good.


__________________________________________________
"Man sacrifices his health in order to make money.
Then he sacrifices money to recuperate his health.
And then he is so anxious about the future that he does not enjoy the present; the result being that he does not live in the present or the future; he lives as if he is never going to die, and then dies having never really lived."   Dalai Lama


Bikes 1993 K1100 LT, 1998 K1100 LT, 1993 K75 RT, 1996 K75RT, 1986 K75 GS, 1979 Z1300 Kawasaki X 2 for now
    

4Back to top Go down   Brakes bled but still spongy feel??? Empty Re: Brakes bled but still spongy feel??? on Wed Jul 04, 2012 9:52 am

Inge K.

Inge K.
VIP
VIP
If don`t remember wrong (which I do quite often) it recently was someone with a ~similar problem in here, in the end it turned out to be non genuine shims fitted between pistons/pads that was flexing.
Just mentions it.


__________________________________________________
Inge K.
K100RS -86. (first owner), K1100LTSE -94.
    

5Back to top Go down   Brakes bled but still spongy feel??? Empty Re: Brakes bled but still spongy feel??? on Wed Jul 04, 2012 9:15 pm

RicK G

RicK G
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Yeah I do remember that but I can never find those posts.
It was some anti vibration pads to stop squealing. They were between the piston and steel backing of the pads and once removed all was good.


__________________________________________________
"Man sacrifices his health in order to make money.
Then he sacrifices money to recuperate his health.
And then he is so anxious about the future that he does not enjoy the present; the result being that he does not live in the present or the future; he lives as if he is never going to die, and then dies having never really lived."   Dalai Lama


Bikes 1993 K1100 LT, 1998 K1100 LT, 1993 K75 RT, 1996 K75RT, 1986 K75 GS, 1979 Z1300 Kawasaki X 2 for now
    

6Back to top Go down   Brakes bled but still spongy feel??? Empty Re: Brakes bled but still spongy feel??? on Wed Jul 04, 2012 9:33 pm

Inge K.

Inge K.
VIP
VIP
Yeah, all that time which is used for searching for old posts...............................
could be used for something else................
I always find out...after.


__________________________________________________
Inge K.
K100RS -86. (first owner), K1100LTSE -94.
    

7Back to top Go down   Brakes bled but still spongy feel??? Empty Re: Brakes bled but still spongy feel??? on Wed Jul 04, 2012 9:52 pm

RicK G

RicK G
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I would be going out for a ride but I am waiting of news on my brother. He was on an adventure trip from Vladivostoc to the western europe and some old idiot ran him of the road in siberia somewhere and he is being airlifted back to Australia to get the neccessary surgery done to a busted left leg. I spoke to him via skype in the hospital in Siberia ( I haven't figured out exactly where yet) and he didn't want it done there because as he said when he went into the hospital he was given a pair of slipon plastis shoe covers and as he said they were to stop the germs getting to him not to stop then comming from outside into the hospital.


__________________________________________________
"Man sacrifices his health in order to make money.
Then he sacrifices money to recuperate his health.
And then he is so anxious about the future that he does not enjoy the present; the result being that he does not live in the present or the future; he lives as if he is never going to die, and then dies having never really lived."   Dalai Lama


Bikes 1993 K1100 LT, 1998 K1100 LT, 1993 K75 RT, 1996 K75RT, 1986 K75 GS, 1979 Z1300 Kawasaki X 2 for now
    

8Back to top Go down   Brakes bled but still spongy feel??? Empty Re: Brakes bled but still spongy feel??? on Thu Jul 05, 2012 7:27 am

Inge K.

Inge K.
VIP
VIP
Sorry to hear about your brother, Rick.
Hope he soon get back from that remote place and have his recovery at a safer place.


__________________________________________________
Inge K.
K100RS -86. (first owner), K1100LTSE -94.
    

9Back to top Go down   Brakes bled but still spongy feel??? Empty Hard feeling in my hand! on Thu Jul 05, 2012 3:40 pm

KJB

KJB
active member
active member
Hi guys,

You were right...I replaced the four pot K1100 calipers with the original Brembo two pots and now I have a hard brake lever! Seems like the original 20mm master cylinder just isn't good enough to power the four pots!

You guys are awesome! Thanks so much for your expertise!

Kind regards Kim

    

10Back to top Go down   Brakes bled but still spongy feel??? Empty Re: Brakes bled but still spongy feel??? on Thu Jul 05, 2012 8:40 pm

Inge K.

Inge K.
VIP
VIP
@KJB wrote:Seems like the original 20mm master cylinder just isn't good enough to power the four pots!

Nice that you got it sorted.............by judging the picture you got a 13mm master.
If you had got a 20mm...it would have been well suited for the four pots.


__________________________________________________
Inge K.
K100RS -86. (first owner), K1100LTSE -94.
    

11Back to top Go down   Brakes bled but still spongy feel??? Empty Brakes spongy on Sat Jul 14, 2012 3:32 pm

pierre12

pierre12
New member
New member
Guys
I had a similar experience and decided to hang the caliper assembly upside down for the night to get any possible air bubbles out. I also tied the brakes and most of the problem was cured. I then re bled the brakes that cured the problem. It seem that air were trapped in bottom of the assembly!
I hope this solve your problems as well
Nice riding

    

12Back to top Go down   Brakes bled but still spongy feel??? Empty Re: Brakes bled but still spongy feel??? on Sun Jul 15, 2012 2:33 am

Two Wheels Better

Two Wheels Better
Moderator
Moderator
@Rick G wrote:That was our GITH but I have heard that a 16mm of the very last of the airheads is a good master cylinder as the brakes come up well and with good feel but the 20mm one is the OEM.
Go over your brake lines to make sure none are expanding or getting big bubbles in the outer sheath. Also if you can use the stainless braided lines they are really good.

A 16mm R65 master cylinder works well with two four pot Brembos, but the 20mm K11 master cylinder works the best. Did it to my K100RS when I swapped to the four pot Brems. All K1100 and R1100 use the 20mm M/C, with or without ABS. Yessir.


__________________________________________________

"It is a capital mistake to theorize before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts."

Arthur Conan Doyle
1970 R60/5, '77 R75/7-R100, '85 K100'87 K75C, '87 K100RS, '93 K11-K12 Big Block, '93 K1100RS, '95 R100-Mystic, '96 K1100RS, '98 K1200RS, '00 K1200RS, '02 K1200RS, '03 K1200GT, '04 R1150R'04 R1150RT, '05 K1200S, '06 K1200R, '07 K1200R, '09 K1300GT & 2013 R1200RT-Polizei  - all of the Beemers in my life I can recall, owned still or sold on.
    

13Back to top Go down   Brakes bled but still spongy feel??? Empty Re: Brakes bled but still spongy feel??? on Sun Jul 15, 2012 7:22 am

Inge K.

Inge K.
VIP
VIP
Guest in the House wrote: All K1100 and R1100 use the 20mm M/C, with or without ABS. Yessir.
Just would like to add to the list.....................K100RS4V and K1.


__________________________________________________
Inge K.
K100RS -86. (first owner), K1100LTSE -94.
    

14Back to top Go down   Brakes bled but still spongy feel??? Empty Re: Brakes bled but still spongy feel??? on Sun Jul 15, 2012 9:24 am

Two Wheels Better

Two Wheels Better
Moderator
Moderator
We would be remiss if we did not also mention that 20mms were also used on the venerable R850R, but only in its early incarnation, pre-R1150. Pedants R Us. It naturally occurs around BMW owners, I have observed. Smile


__________________________________________________

"It is a capital mistake to theorize before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts."

Arthur Conan Doyle
1970 R60/5, '77 R75/7-R100, '85 K100'87 K75C, '87 K100RS, '93 K11-K12 Big Block, '93 K1100RS, '95 R100-Mystic, '96 K1100RS, '98 K1200RS, '00 K1200RS, '02 K1200RS, '03 K1200GT, '04 R1150R'04 R1150RT, '05 K1200S, '06 K1200R, '07 K1200R, '09 K1300GT & 2013 R1200RT-Polizei  - all of the Beemers in my life I can recall, owned still or sold on.
    

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