100% Biker & Trike Magazine Forums

Go Back   100% Biker & Trike Magazine Forums > 100% Biker > Trike Magazine

Notices

Reply
 
Thread Tools Display Modes
  #1  
Old 08-04-2009, 04:00 PM
Acker Acker is offline
Chat Slapper
 
Join Date: Jul 2008
Posts: 57
Default Disc conversion - Master cylinder

Just done a disc conversion -using vauxhall discs and mondeo calipers with mechanical handbrake.
I can't seem to get the pressure up to operate the calipers properly - despite several attempts at bleeding the system and i can't see any air bubbles.
I am using a master cylinder suitable for kit car purposes and i am wondering if I use a heavier duty cylinder this would solve the problem.
Any ideas on what to use? - i'm thinking landrover CV type.
Reply With Quote
  #2  
Old 08-04-2009, 06:40 PM
johnr johnr is offline
Talk, Type, Breath, Talk, Type, Breath....
 
Join Date: Jan 2005
Location: preston, lancs
Posts: 3,530
Default

try forcing fluid under pressure using a syringe from the calipers back into the master cylinder.
__________________
in sidecars, no one can hear you scream!





http://www.katanaownersclub.co.uk/forum/index.php
Reply With Quote
  #3  
Old 08-04-2009, 07:58 PM
Blackjack Blackjack is offline
Been out, but rather stay in!
 
Join Date: May 2004
Location: Bristol
Posts: 1,301
Default

Quote:
Originally Posted by Acker View Post
Just done a disc conversion -using vauxhall discs and mondeo calipers with mechanical handbrake.
I can't seem to get the pressure up to operate the calipers properly - despite several attempts at bleeding the system and i can't see any air bubbles.
I am using a master cylinder suitable for kit car purposes and i am wondering if I use a heavier duty cylinder this would solve the problem.
Any ideas on what to use? - i'm thinking landrover CV type.

Did it work before?
Reply With Quote
  #4  
Old 08-04-2009, 08:25 PM
dubmeister's Avatar
dubmeister dubmeister is offline
Chatter Box
 
Join Date: Mar 2008
Location: Carlisle
Posts: 383
Default

I am having exactly the same trouble on my z13 trike but am using the standard z13 master cylinder
Reply With Quote
  #5  
Old 08-04-2009, 11:43 PM
Blackjack Blackjack is offline
Been out, but rather stay in!
 
Join Date: May 2004
Location: Bristol
Posts: 1,301
Default

Quote:
Originally Posted by dubmeister View Post
I am having exactly the same trouble on my z13 trike but am using the standard z13 master cylinder
Master cylinder's too small and/or the pedal ratio is wrong.

You got car drums on the rear you probably want a 5/8" bore master cylinder (and a bike one of the right bore often won't displace enough fluid) and a pedal ratio of 6:1.

Though, with a Z1300, you might be in with half a chance of the pedal ratio being in the ball park if it's the original pedal.

Big tall wheels is another problem. If it's a Ford axle you either want the big drums (9"?) or a disc conversion, poxy little Escort brakes (8"?) and huge wheels isn't a good combination anyway.

6:1 is pretty much a standardised pedal ratio for car stuff so that might be the problem with the discs too....
Reply With Quote
  #6  
Old 09-04-2009, 11:25 AM
dubmeister's Avatar
dubmeister dubmeister is offline
Chatter Box
 
Join Date: Mar 2008
Location: Carlisle
Posts: 383
Default

Thread hijack in progress
The standard z13 master cylinder is 5/8 bore so as you say should be somewhere in the ballpark
The back axle is reliant with nova discs and golf gti calipers (single pot sliders )and standard z13 brake pedal
I was working in the vain hope that the standard z13 rear caliper is a big ole beast and having two single pot sliding calipers would hopefully be a similar sort of fluid displacement
I havent ruled out a fucked golf caliper being in the mix yet either i will go and get a couple more anyway i think as they are only 15 each complete at the local scrappy
Reply With Quote
  #7  
Old 09-04-2009, 12:13 PM
Blackjack Blackjack is offline
Been out, but rather stay in!
 
Join Date: May 2004
Location: Bristol
Posts: 1,301
Default

Quote:
Originally Posted by dubmeister View Post
Thread hijack in progress
The standard z13 master cylinder is 5/8 bore so as you say should be somewhere in the ballpark
The back axle is reliant with nova discs and golf gti calipers (single pot sliders )and standard z13 brake pedal
I was working in the vain hope that the standard z13 rear caliper is a big ole beast and having two single pot sliding calipers would hopefully be a similar sort of fluid displacement
I havent ruled out a fucked golf caliper being in the mix yet either i will go and get a couple more anyway i think as they are only 15 each complete at the local scrappy
That's not what I said at all.

I said it won't displace enough fluid even if it is 5/8" bore.

I said the pedal ratio might be in the ballpark.
Reply With Quote
  #8  
Old 09-04-2009, 02:01 PM
dubmeister's Avatar
dubmeister dubmeister is offline
Chatter Box
 
Join Date: Mar 2008
Location: Carlisle
Posts: 383
Default

I stand corrected obe wan
What about a universal 7/8 (19mm) brake/clutch master cylinder ,do the job ? if correctly mounted of course
Running forward controls connected to standard pedal via half inch(ish) hex bar to the standard pedal which has a 3mm thick inch wide tag welded on so it drops down below the pivot point by about 1 3/4" so could run the 7/8 master cylinder directly behind that as long as i get the ratio right
Reply With Quote
  #9  
Old 09-04-2009, 03:11 PM
Acker Acker is offline
Chat Slapper
 
Join Date: Jul 2008
Posts: 57
Default

What about a landrover clutch cylinder?
would this suffice?
Reply With Quote
  #10  
Old 09-04-2009, 04:17 PM
dubmeister's Avatar
dubmeister dubmeister is offline
Chatter Box
 
Join Date: Mar 2008
Location: Carlisle
Posts: 383
Default

I was gonna use a universal one coz it was 12.99 brand new on ebay and they are more than that secondhand in the scrappys
Reply With Quote
  #11  
Old 09-04-2009, 05:19 PM
Acker Acker is offline
Chat Slapper
 
Join Date: Jul 2008
Posts: 57
Default

Quote:
Originally Posted by dubmeister View Post
I was gonna use a universal one coz it was 12.99 brand new on ebay and they are more than that secondhand in the scrappys
That's what i'm using now - was working ok but will not diperse enough pressure for the calipers i'm using.
Tried it again today - extended my 'lever' to give more movement but now looks like its blown the seals on the master cylinder.
I just got a gut feeling that i need a heavier duty one.
By the way - it was working ok (least i thought so) but it was when i came to MOT it - Rollin road said NO! 10% under.
Reply With Quote
  #12  
Old 09-04-2009, 06:28 PM
Blackjack Blackjack is offline
Been out, but rather stay in!
 
Join Date: May 2004
Location: Bristol
Posts: 1,301
Default

Quote:
Originally Posted by dubmeister View Post
I stand corrected obe wan
What about a universal 7/8 (19mm) brake/clutch master cylinder ,do the job ? if correctly mounted of course
Running forward controls connected to standard pedal via half inch(ish) hex bar to the standard pedal which has a 3mm thick inch wide tag welded on so it drops down below the pivot point by about 1 3/4" so could run the 7/8 master cylinder directly behind that as long as i get the ratio right
19mm is 3/4"

7/8" is 22mm.



A 5.8" CAR M/cylinder will probably work fine with your brakes, if it doesn't and the pedal goes hard before you get an brakes, you need a SMALLER bore master cylinder, or, you have a pedal ration that is too low.
Reply With Quote
  #13  
Old 09-04-2009, 06:31 PM
Blackjack Blackjack is offline
Been out, but rather stay in!
 
Join Date: May 2004
Location: Bristol
Posts: 1,301
Default

Quote:
Originally Posted by Acker View Post
That's what i'm using now - was working ok but will not diperse enough pressure for the calipers i'm using.
Tried it again today - extended my 'lever' to give more movement but now looks like its blown the seals on the master cylinder.
I just got a gut feeling that i need a heavier duty one.
By the way - it was working ok (least i thought so) but it was when i came to MOT it - Rollin road said NO! 10% under.
Again, change the pedal ratio and/or fit a SMALLER bore master cylinder.
Reply With Quote
  #14  
Old 16-04-2009, 04:41 PM
Acker Acker is offline
Chat Slapper
 
Join Date: Jul 2008
Posts: 57
Default

Just an update - fitted the landrover master cylinder (its a clutch one from series 3- i forgot to mention!) bled brakes and hey presto nice pressure and rear wheels now lock.
Reply With Quote
  #15  
Old 24-04-2009, 07:58 PM
v8_trike's Avatar
v8_trike v8_trike is offline
Been out, but rather stay in!
 
Join Date: Dec 2007
Location: North Lincs
Posts: 1,321
Default

Just got one of these myself from e-bay, can recommend highly the seller (eliezer72) cheap as well at 10.58

__________________
Too many projects, not enough time (or )
Reply With Quote
  #16  
Old 17-05-2009, 05:12 PM
mideki mideki is offline
Chat Virgin
 
Join Date: Sep 2008
Posts: 45
Smile

Hi Had the same problem even bought a pressure break bleeder. What I had done was installed them with the bleed nipples facing down so could not get all the air out, I removed them but pipes stil coupled inserted a steel plate the same thickness of the calliper held them so the bleed nipple was in the opposite direction 5 min later I had bleed them and the breaks were fine and passed the SVA. Hope this helps
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT. The time now is 06:16 PM.


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2017, vBulletin Solutions, Inc.