master cyl for CJ7 with disc brake conversion? - JeepForum.com
Search  
Sign Up   Today's Posts
User: Pass: Remember?
Advertise Here
Jeep Home Jeep Forum Jeep Classifieds Jeep Registry JeepSpace Jeep Reviews Jeep Gallery Jeep Clubs Jeep Groups Jeep Videos Jeep Events Jeep Articles
Go Back JeepForum.com > Models > Jeep CJ Forum > master cyl for CJ7 with disc brake conversion?

FS: 2007-2013 Jeep Wrangler "HALO" Angel Eye KitTHE NEW! VANCO DUAL MODE 15/16″ Big Brake Kit w/BlaFS: Wranger BRIGHT License Plate LED! Just $3! Great value

Reply
Unread 06-26-2013, 09:30 AM   #1
gabbagabba
Registered User
2014 WK 
 
Join Date: Jan 2013
Location: Southwest, NH
Posts: 383
master cyl for CJ7 with disc brake conversion?

Just bought a 86 cj7 a few weeks ago. The brakes are terrible, no way I could stop in a hurry if someone pulled out or whatever. Downshifting actually stops it better

My mechanic is looking it over and plans to replace the currently leaking master cyl. He thinks the one in their now is OEM or similar spec and looks to him to be a drum brake style master cyl

He notes that disc brake conversion kits for these do not spec a new or diff type master cyl and a mech buddy of him who works at a 4x4 shop also told him to continue with OEM style master cyl, not upgrade to a disc style one?

Thoughts?

I was told when I bought it from a jeep shop that I would have to learn to live with sh**tty brakes on a CJ7, but it seems that something can be done?

Thx!

gabbagabba is offline   Reply With Quote
Unread 06-26-2013, 09:54 AM   #2
gabbagabba
Registered User
2014 WK 
 
Join Date: Jan 2013
Location: Southwest, NH
Posts: 383
sorry

for some reason my other thread about this did not pop up and I reposted with this. sorry for the double post, mods please delete the other one if needed

please reply to this one, thx
gabbagabba is offline   Reply With Quote
Unread 06-26-2013, 12:49 PM   #3
texasdave
Senior Member
 
texasdave's Avatar
1980 CJ7 
 
Join Date: Dec 2007
Location: Killeen, Texas
Posts: 912
Upgrade to power brakes. Get a booster from a 95 yj and master cylinder to match it. It will improve you braking greatly. I would be leery of a mechanic telling me I have to live with crappy brakes just because it is a jeep. If you're running stock size tires no problem but if you go bigger you need to upgrade.
texasdave is offline   Reply With Quote
Unread 06-26-2013, 01:01 PM   #4
CSP
Registered User
 
Join Date: Aug 2002
Location: Colorado
Posts: 11,813
So are we to assume that your rear brakes have been upgraded to disc?

Power brakes won't fix a master that isn't sufficiently sized for the fluid demands of rear calipers, if that's the case. It would be helpful to know if in fact it does have rear discs, and what the calipers are out of.
CSP is offline   Reply With Quote
Unread 06-26-2013, 01:27 PM   #5
gabbagabba
Registered User
2014 WK 
 
Join Date: Jan 2013
Location: Southwest, NH
Posts: 383
Quote:
Originally Posted by texasdave View Post
Upgrade to power brakes. Get a booster from a 95 yj and master cylinder to match it. It will improve you braking greatly. I would be leery of a mechanic telling me I have to live with crappy brakes just because it is a jeep. If you're running stock size tires no problem but if you go bigger you need to upgrade.
Goos info, makes sense, will relay that to my mechanic, or find a new one.... It was the place selling me the Jeep that told me 'that is CJ brakes'
gabbagabba is offline   Reply With Quote
Unread 06-26-2013, 06:08 PM   #6
84scrambler
Registered User
1984 CJ8 
 
Join Date: Jul 2005
Posts: 169
What exactly do you mean by disc brake conversion kit? Why do you think there's a drum brake master cylinder?

From the factory you should have discs up front and drums in the back, assuming nobody screwed with the thing. If you have stocks size tires then that jeep will stop no problem. Did somebody try and put a disc brake kit in the rear?

With 33" tires on my CJ8 and stock non power brakes my jeep couldn't lock up the tires but it still stopped fairly well. There are many options available if you would like to upgrade, but you have to be careful to make sure the master cylinder is sized correctly for the rear and front brakes.
84scrambler is offline   Reply With Quote
Unread 06-26-2013, 09:38 PM   #7
CSP
Registered User
 
Join Date: Aug 2002
Location: Colorado
Posts: 11,813
Quote:
Originally Posted by gabbagabba View Post
Goos info, makes sense,
Actually it doesn't. Power brakes just add assist or less pedal pressure. If the volume of the master cylinder isn't correct for the rest of the braking system, or the proportion between front and rear isn't correct, adding assist isn't going to change any of those variables. My CJ5 stops perfectly on 37" tires on heavy, one ton axles. I do not have power brakes either, but my braking system is a matched system.

We still don't know if you're talking about the rear brakes being converted to disc or if you're assuming that CJs had drums on all four corners and just have disc in front.
CSP is offline   Reply With Quote
Unread 06-26-2013, 10:39 PM   #8
dg6772
Registered User
1986 CJ7 
 
Join Date: Feb 2011
Location: Muskegon, Michigan
Posts: 1,314
I upgraded my 86 to 4wheel disc. I used a Corvette master because it has enough capicty for the disc calipers.

Dave in Muskegon
dg6772 is offline   Reply With Quote
Unread 06-27-2013, 07:17 AM   #9
gabbagabba
Registered User
2014 WK 
 
Join Date: Jan 2013
Location: Southwest, NH
Posts: 383
Quote:
Originally Posted by CSP View Post
Actually it doesn't. Power brakes just add assist or less pedal pressure. If the volume of the master cylinder isn't correct for the rest of the braking system, or the proportion between front and rear isn't correct, adding assist isn't going to change any of those variables. My CJ5 stops perfectly on 37" tires on heavy, one ton axles. I do not have power brakes either, but my braking system is a matched system.

We still don't know if you're talking about the rear brakes being converted to disc or if you're assuming that CJs had drums on all four corners and just have disc in front.
It is at the shop now and I have not pulled the wheels off myself. My understanding is that disc's are stock up front and that it also has disc's now in the back. So I am under the assumption that it now has disc's at all four corners, I will confirm
gabbagabba is offline   Reply With Quote
Unread 06-27-2013, 10:37 AM   #10
dandd
Registered User
1982 CJ8 
 
Join Date: Oct 2012
Location: San Jose, California
Posts: 64
I have the same setup in a cj8 (Scrambler) with 35" all the added steel and 4 wheel disc. The MC is vette 1 1/8 with dual diaphragm booster and a adjustable rear proportioning valve (required). This setup is minimally acceptable for a dally driver.
The next step would be to increase the front braking capacity with wilwood 12" 4 piston jeep CJ upgrade. This will require 16" or larger rim, which I have. $900 ebay
Hope this helps.
http://wilwood.com/BrakeKits/BrakeKi...ion=All&whl=16
dandd is offline   Reply With Quote




Jeep, Wrangler, Cherokee, Grand Cherokee, and other models are copyrighted and trademarked to Jeep/Chrysler Corporation. JeepForum.com is not in any way associated with Jeep or the Chrysler Corp.