NAXJA Forums -::- North American XJ Association  

Go Back   NAXJA Forums -::- North American XJ Association > NAXJA Unibody Jeep Technical Forums > Jeep Cherokee XJ (1984 - 2001) > Modified Tech Discussion
HOME Member FAQ Sponsor Info Rules Bylaws E-Mail

Modified Tech Discussion Forum for Tech related discussion for Modified XJ's and MJ's.

Reply
 
Thread Tools Display Modes
  #1  
Old November 21st, 2016, 07:41
RCP Phx RCP Phx is offline
NAXJA Forum User
 
Join Date: Mar 2003
Location: Phoenix,Az
Posts: 14,560
The elusive master cylinger upgrade ???

So after doing my WJ/KJ brakes, I have poor pedal travel. I spent most of the day(and night) reading all the different forums looking for some info on a larger MC that will fit a late model vac booster. I looked at over 500 MC specs and came up with some possibilities. Going to make some phone calls today! Not sure about the size needed but its a start. Just for reference here are the ratio's for factory parts with some different MC's. I'm leaning towards the 1-1/16" to start.

Using my 2000 with a 1" bore as a baseline.............
Front XJ caliper - 6.72/1 (x 2)
Rear wheel cylinder - (-).66/1 (x2)

KJ rear caliper - 3.77/1 (x2)

WJ front caliper - 3.77/1 (x4)

Here are some WJ/KJ #'s with different MC's...........

1-1/16" MC - 3.34/1 (x6)

1-1/8" MC - 2.97/1 (x6)
Reply With Quote
  #2  
Old November 21st, 2016, 16:09
Jeep Driver Jeep Driver is offline
NAXJA Forum User
 
Join Date: Jun 2016
Location: Parrottsville
Posts: 703
Re: The elusive master cylinger upgrade ???

1" bore is sufficient. I takes no more fluid/travel to actuate two pistons than it does one.
Reply With Quote
  #3  
Old November 21st, 2016, 16:35
RCP Phx RCP Phx is offline
NAXJA Forum User
 
Join Date: Mar 2003
Location: Phoenix,Az
Posts: 14,560
Re: The elusive master cylinger upgrade ???

Quote:
Originally Posted by Jeep Driver View Post
1" bore is sufficient. I takes no more fluid/travel to actuate two pistons than it does one.
Wow!!
Reply With Quote
  #4  
Old November 21st, 2016, 20:14
techno1154's Avatar
techno1154 techno1154 is offline
NAXJA Member
 
Join Date: Apr 2003
Location: In the islands
Posts: 2,589
Re: The elusive master cylinger upgrade ???

Quote:
Originally Posted by Jeep Driver View Post
1" bore is sufficient. I takes no more fluid/travel to actuate two pistons than it does one.
My XJ have been fitted with the first generation WK '05 to '10 front rotors and calipers for almost a year. Several years ago I retro fitted the ZJ rear disc backing plate and the Ford Explorer calipers and rotors. There is no discernable difference in pedal travel. I am still using the original master cylinder which is 20+ years old.

According to my research, the above mentioned WK uses a 1.062" bore master cylinder. I do not know if it would fit the XJ brake booster. The WK2 2011 to ?? uses an even bigger bore master cylinder.
__________________
Patrick

#594
1996 XJ; 4.0L; AW4; NP231; SYE; D30 and D44; ECTED; 4.10 gears; 30X9.5 -15 BFG/AT/KO; 3" lift; Rusty's LCA; JKS ADJ UCA; Kevins ADJ Track bar; Drawtite Front Receiver; Dual Electric Fans; Dual Battaries.
Reply With Quote
  #5  
Old November 21st, 2016, 21:42
Jeep Driver Jeep Driver is offline
NAXJA Forum User
 
Join Date: Jun 2016
Location: Parrottsville
Posts: 703
Re: The elusive master cylinger upgrade ???

Quote:
Originally Posted by RCP Phx View Post
Wow!!
Spend a few grand on Brembos, then you can WOW me all you want.
Reply With Quote
  #6  
Old November 21st, 2016, 21:58
Jeep Driver Jeep Driver is offline
NAXJA Forum User
 
Join Date: Jun 2016
Location: Parrottsville
Posts: 703
Re: The elusive master cylinger upgrade ???

FWIW to you...........


Just Saturday evening I bought a new MC for a '97ZJ to replace the '97ZJ MC I already have (strictly for appearance sake, there is nothing wrong with my current MC). I'm using a '04WJ booster.

I did this with the anticipation of doing the WJ knuckle swap in the Spring. NAPA currently has my MC with the Intrepid SS lines I was using. They are making my up a set of SS lines to the distribution block (no metering). Lines will cost me over $100.

I did not spend $200 out of ignorance nor stupidity.

My engine bay is completely stripped, painted, awaiting a my new engine.


One swap is '70 Corvette MC, 1 1/8 bore, you can look that one up.
Reply With Quote
  #7  
Old November 22nd, 2016, 06:13
RCP Phx RCP Phx is offline
NAXJA Forum User
 
Join Date: Mar 2003
Location: Phoenix,Az
Posts: 14,560
Re: The elusive master cylinger upgrade ???

Neither the WK or a Corvette will fit a XJ booster. I find it hard to believe that after all these years and members this hasn't been resolved yet!

If push comes to shove, I'll build a "Fraken-cylinder" that fits!
Reply With Quote
  #8  
Old November 22nd, 2016, 06:50
Jeep Driver Jeep Driver is offline
NAXJA Forum User
 
Join Date: Jun 2016
Location: Parrottsville
Posts: 703
Re: The elusive master cylinger upgrade ???

The Corvette MC does fit.

No one said anything about a WK MC or booster.

Although the WK does have a version of the 8.25..........very little info found on them..........however, that would be a rear swap to look into.

Here is the GM swap- http://www.bsfab.net/?p=58
Reply With Quote
  #9  
Old November 22nd, 2016, 10:05
cal's Avatar
cal cal is offline
NAXJA Warranty Voider
 
Join Date: Nov 2004
Location: Hammertown, USA
Posts: 17,691
Re: The elusive master cylinger upgrade ???

It hasn't been resolved because its the solution to a problem that does not exist.

Going to a bigger bore just means you push the pedal harder for less distance with no change in braking performance. WJ's come with a 1" bore master and don't have problems, if you are having problems you need to figure out what is wrong with your car, not reinvent the wheel.
__________________
I'm not a complete idiot - there are parts missing.
Reply With Quote
  #10  
Old November 22nd, 2016, 15:53
RCP Phx RCP Phx is offline
NAXJA Forum User
 
Join Date: Mar 2003
Location: Phoenix,Az
Posts: 14,560
Re: The elusive master cylinger upgrade ???

It's a personal preference(nothing is wrong), but I don't care for it. The 1-1/16" bore should increase pedal effort and decrease pedal travel by about 12%! I prefer more input/feedback.
Reply With Quote
  #11  
Old November 22nd, 2016, 16:36
ROKRWLR ROKRWLR is offline
NAXJA Forum User
 
Join Date: Mar 2003
Location: Arvada, CO
Posts: 256
Re: The elusive master cylinger upgrade ???

2001 Dodge 2500 MC is a 99% direct bolt in. You need an extended threaded adjuster in between it and the booster. I used a bolt with the head ground down to be round like the factory. Brake lines bolt right in with a little flexing.

This MC stops big 1 ton calipers with no problem. This might be too much for what you need? But it fixed me needing to pump the pedal to get enough fluid to my bigger calipers.

When I did this, there were a few threads around that include the Autozone part number.

wait... found it: ’99 + Dodge Ram 2500 (AutoZone #348202)

http://www.pirate4x4.com/forum/jeep-...ade-yj-tj.html

Last edited by ROKRWLR; November 22nd, 2016 at 16:43.
Reply With Quote
  #12  
Old November 22nd, 2016, 19:16
yossarian19's Avatar
yossarian19 yossarian19 is offline
NAXJA Forum User
 
Join Date: Mar 2007
Location: Grass Valley, CA
Posts: 3,480
Re: The elusive master cylinger upgrade ???

I think I used a '98 Durango MC, want to say it was 1 1/8 bore. Pedal feel was awesome but you definitely notice, too, that you have to push harder for the same brake performance. I'm with you on the preference for a stiff, low travel pedal
Reply With Quote
  #13  
Old November 22nd, 2016, 22:59
madmax's Avatar
madmax madmax is offline
NAXJA Forum User
 
Join Date: Mar 2006
Location: Woodburn, OR
Posts: 391
Re: The elusive master cylinger upgrade ???

I'm running the 80s ford e350 master 1-1/8 bore. 100% bolt it aside from swapping fron fitting out

I have a wj swap upfront on a hp30 and a eb 9" with 11" f150 drum and 1-1/16 crown vic police wheel cylinders. I have great stripping power
Reply With Quote
  #14  
Old November 23rd, 2016, 07:40
cal's Avatar
cal cal is offline
NAXJA Warranty Voider
 
Join Date: Nov 2004
Location: Hammertown, USA
Posts: 17,691
Re: The elusive master cylinger upgrade ???

Quote:
Originally Posted by madmax View Post

I have a wj swap upfront on a hp30 and a eb 9" with 11" f150 drum and 1-1/16 crown vic police wheel cylinders. I have great stripping power

__________________
I'm not a complete idiot - there are parts missing.
Reply With Quote
  #15  
Old November 23rd, 2016, 07:43
RCP Phx RCP Phx is offline
NAXJA Forum User
 
Join Date: Mar 2003
Location: Phoenix,Az
Posts: 14,560
Re: The elusive master cylinger upgrade ???

Well the Dodge Ram 2500 uses a 1-1/4" MC, I haven't done any calcs for that because most said it's too large.

As for the Durango MC it is 1-1/16" so I will look into that one!
Reply With Quote
Reply


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

Similar Threads
Thread Thread Starter Forum Replies Last Post
Master cylinder upgrade coloradoinsane Modified Tech Discussion 36 October 14th, 2015 09:29
Brake master upgrade for 97+ Alboy97XJ Modified Tech Discussion 18 December 6th, 2014 04:31
WJ Master Upgrade blondejoncherokee Modified Tech Discussion 9 December 10th, 2013 08:10
Master Cylinder upgrade (post 97 XJ's) sampil Modified Tech Discussion 14 October 4th, 2006 19:04
master cylinder upgrade wolfpackjeeper Modified Tech Discussion 4 November 8th, 2005 22:12


All times are GMT -7. The time now is 14:56.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2021, vBulletin Solutions, Inc.
NAXJA and NAXJA logo's Copyright NAXJA. All content/images Copyright NAXJA 1999-2014