XJS ( X27 ) 1975 - 1996 3.6 4.0 5.3 6.0

Rear disk brake retrofit?

Thread Tools
 
Search this Thread
 
Old Feb 11, 2017 | 02:05 PM
  #1  
Jagboi64's Avatar
Thread Starter
|
Veteran Member
10 Year Member
Liked
Loved
Community Favorite
Joined: Jan 2013
Posts: 5,250
Likes: 3,509
From: Calgary, Canada
Default Rear disk brake retrofit?

Is it possible to retrofit the vented brakes from a 99 XJ8? I know the callipers will be different, but assuming I can get everything from the XJ8, will the bracket bolt up to the XJS hub?

Is there a difference in the piston diameter than will affect the front-rear balance?

I also run a set of 15" rims, would the XJ8 brakes clear a 15" rim?

I'm planning an IRS overhaul for my Daimler DS420, and an outboard brake conversion is in the works. I've already figured out the necessary parts for the halfshafts and hubs that are different, looking at braking options now.
 
Reply
Old Feb 11, 2017 | 04:55 PM
  #2  
Jagboi64's Avatar
Thread Starter
|
Veteran Member
10 Year Member
Liked
Loved
Community Favorite
Joined: Jan 2013
Posts: 5,250
Likes: 3,509
From: Calgary, Canada
Default

I can answer part of my own question. I have a 1995 XJR hub in the garage and it wouldn't fit in a 15" Kent rim. The 99 XJ8 disk is the same diameter as the 1995 XJR, just vented. So much for the bigger brakes idea!

I believe the XJ40 brakes and hubs can be retrofitted though to give outboard brakes.
 
Reply
Old Feb 12, 2017 | 02:25 AM
  #3  
Beavis's Avatar
Senior Member
Joined: Jul 2010
Posts: 257
Likes: 105
From: Rugby
Default

Hi,

I purchased a later outboard IRS which I used for updating my 92 XJR-S. During that swap I replaced the rear outboard brakes\hubs with those from a 99 XJR. Bolted straight on. Two issues to be aware of, I needed to make a spacer for the drive shafts otherwise there was excessive camber on the rear wheels, and secondly getting the ABS working\functioning properly was a labour of love!!

Need to be mindful that I was after larger vented disks on the rear, and I have 17" revolver XJR wheels on my car which were needed to clear the disks\calipers.

Beavis.




x308 XJR hubs and disks during install on my XJR-S



Disks just showing through revolvers...
 
Reply
Old Feb 15, 2017 | 12:42 PM
  #4  
Paul_59's Avatar
Banned
Joined: Oct 2014
Posts: 832
Likes: 328
From: https://t.me/pump_upp
Default

Later xjs post 93 (actually made from mid 1993) had outboard rear discs, early model 6.0 had solid rear discs, from 94 or 95 they went to vented rear discs, I believe these can be retrofitted to earlier models with outboard rear discs, but you would require discs, pads and rear brake calipers.

​​​​​​​
 
Reply
Old Feb 15, 2017 | 01:34 PM
  #5  
Daim's Avatar
Veteran Member
Joined: May 2014
Posts: 5,906
Likes: 2,182
From: Bremen, Germany
Default

Originally Posted by Beavis
Hi,

I purchased a later outboard IRS which I used for updating my 92 XJR-S. During that swap I replaced the rear outboard brakes\hubs with those from a 99 XJR. Bolted straight on. Two issues to be aware of, I needed to make a spacer for the drive shafts otherwise there was excessive camber on the rear wheels, and secondly getting the ABS working\functioning properly was a labour of love!!

Need to be mindful that I was after larger vented disks on the rear, and I have 17" revolver XJR wheels on my car which were needed to clear the disks\calipers.

Beavis.




x308 XJR hubs and disks during install on my XJR-S



Disks just showing through revolvers...

Just a side note, they aren't revolver rims but sport rims from the XJR6 (X300)... The revolver rims are these here and were introduced with the X100 XK8:

 

Last edited by Daim; Feb 15, 2017 at 01:36 PM.
Reply
Old Feb 15, 2017 | 03:35 PM
  #6  
Jagboi64's Avatar
Thread Starter
|
Veteran Member
10 Year Member
Liked
Loved
Community Favorite
Joined: Jan 2013
Posts: 5,250
Likes: 3,509
From: Calgary, Canada
Default

Originally Posted by Paul_59
Later xjs post 93 (actually made from mid 1993) had outboard rear discs, early model 6.0 had solid rear discs, from 94 or 95 they went to vented rear discs, I believe these can be retrofitted to earlier models with outboard rear discs, but you would require discs, pads and rear brake calipers.

​​​​​​​
Need 16" wheels too, if its the same caliper and disk size as the X300/308. I tried fitting an X300 hub and caliper in to a 15" rim and no go. From what I can tell, it looks like the larger 305mm rotor, so same rear brakes as X308.
 
Reply
Old Feb 16, 2017 | 02:09 PM
  #7  
Paul_59's Avatar
Banned
Joined: Oct 2014
Posts: 832
Likes: 328
From: https://t.me/pump_upp
Default

Originally Posted by Jagboi64
Need 16" wheels too, if its the same caliper and disk size as the X300/308. I tried fitting an X300 hub and caliper in to a 15" rim and no go. From what I can tell, it looks like the larger 305mm rotor, so same rear brakes as X308.
Thanks for your correction, I forgot to mention that as far as I know all 93 onwards models had 16 inch wheels as standard
 
Reply

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 



All times are GMT -5. The time now is 06:44 AM.