Forum Home Forum Home > CJ-2A Discussion Area > Tech Questions and Answers
  New Posts New Posts RSS Feed - Master cylinder- rebuild or replace?
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

Master cylinder- rebuild or replace?

 Post Reply Post Reply
Author
Message
Scott R View Drop Down
Member
Member
Avatar

Joined: 16 Mar. 2007
Location: Gaines, MI
Status: Offline
Points: 1387
Post Options Post Options   Thanks (0) Thanks(0)   Quote Scott R Quote  Post ReplyReply Direct Link To This Post Topic: Master cylinder- rebuild or replace?
    Posted: 06 May 2007 at 5:38am

Never done a master cylinder rebuild before, but always willing to explore the unknown. Would like to know from those that have been there done thatů is the cost, time, trouble worth rebuilding vs. just buying a new one?

Michigan Flat Fender Club on Facebook

1949 CJ2A #221621

1965 CJ-5
Back to Top
Bluax View Drop Down
Member
Member


Joined: 04 Feb. 2006
Location: Phoenix
Status: Offline
Points: 750
Post Options Post Options   Thanks (0) Thanks(0)   Quote Bluax Quote  Post ReplyReply Direct Link To This Post Posted: 06 May 2007 at 5:44am
If I can do it, ANYBODY can do it!  and I've done it at least 4 or 5 times and have now even graduated up to rebuilding fuel pumps.   Degree of success on the master cylinder can, however, depend on the bore wear.  When disassembling just lay the parts out in order (assuming it was working before, if not, its a fairly logical system).
 
B
Mountains ta climb, roads ta drive an' rivers ta paddle .... now 'Ride Bambino, Ride!'
Back to Top
F Bill View Drop Down
Member
Member
Avatar
Sponsor Member x 2

Joined: 05 Dec. 2005
Location: central Texas
Status: Offline
Points: 7681
Post Options Post Options   Thanks (0) Thanks(0)   Quote F Bill Quote  Post ReplyReply Direct Link To This Post Posted: 06 May 2007 at 10:43am
If you can operate a brake cylinder hone and a spray can, you can do a master cylinder. Make certain the old stuff matches the new stuff and that the piston returns as far with the new stuff installed as it did before.  Some kits seem to contain extra parts that if installed keep the piston from a full return, and they don't let the bleedback hole inside the bore get uncovered, so the brakes tend to build up pressure and drag.
 
If the bore cleans up nicely without pitting in the crucial areas where the seals would be during operation, you should have it made in the shade. Be certain to clean out all the holes and passageways with compressed air or whatever....(not that there are many to clean but there are all important.....)
 
If you want more info check out an older motors manual from the library and read up on brake parts rebuilding.  Newer manuals don't cover it much as it is more practical for a shop to simply install rebuilts.
 
When you reinstall, pay close attention to pedal freeplay and brake pushrod freeplay measurements. Making the pedal too "tight" will also allow the pedal to hold the master piston partially engaged and create drag in the brakes that only will go away if you bleed away the pressure ....and it will build right back up next time you use the brakes.
If you haven't checked out the tech FAQ section, go to:
http://www.thecj2apage.com/forums/tech-faq_forum57.html
for a lot of great stuff you need to know!!

Back to Top
hillbilly21 View Drop Down
Member
Member
Avatar
Sponsor Member

Joined: 18 June 2006
Location: USA
Status: Offline
Points: 4841
Post Options Post Options   Thanks (0) Thanks(0)   Quote hillbilly21 Quote  Post ReplyReply Direct Link To This Post Posted: 06 May 2007 at 11:25am
 Save time ..replace it with a new one for under 60.00....get the Jeep on the road summer is coming Wink
1946 CJ2a POW-MIA
51 M38 DOC. ORIGINAL
www.eastcoastwillys.org
59-WILLYS TRUCK
PRES NC FLAT FENDERS CLUB
www.eastcoastwillys.org
hillbillystoys.phanfare.co
Back to Top
Turtleherder View Drop Down
Member
Member
Avatar

Joined: 15 Jan. 2006
Location: Asheboro, NC
Status: Offline
Points: 303
Post Options Post Options   Thanks (0) Thanks(0)   Quote Turtleherder Quote  Post ReplyReply Direct Link To This Post Posted: 06 May 2007 at 2:32pm
Hillbilly. You and I both know the pleasure and reward of doing it ourselves and reaping the benefits later. Done right. It shouldn't take much longer than to just replace the old one with a NROS. Remember, there isn't an endless stream of parts. I say, let the rookie go for it.
Turtleherder,
'46CJ2A, 77547
'46CJ2A, 83055
'48CJ3A 211398
'48B1PW
"We, the willing, led by the unknowing, have been doing so much, with so little, for so long, we can now do anything with nothing."
Back to Top
Scott R View Drop Down
Member
Member
Avatar

Joined: 16 Mar. 2007
Location: Gaines, MI
Status: Offline
Points: 1387
Post Options Post Options   Thanks (0) Thanks(0)   Quote Scott R Quote  Post ReplyReply Direct Link To This Post Posted: 06 May 2007 at 3:27pm
Originally posted by F Bill F Bill wrote:

Make certain the old stuff matches the new stuff and that the piston returns as far with the new stuff installed as it did before.  
 
If the bore cleans up nicely without pitting in the crucial areas where the seals would be during operation, you should have it made in the shade. 
 
You may have just provided the key phrases to my decision. It's not that this one doesn't work very well... it's completly shot and has been for a long time. Guess I need dig into it and see if there is any corrosion.
Michigan Flat Fender Club on Facebook

1949 CJ2A #221621

1965 CJ-5
Back to Top
uglyjeep View Drop Down
Member
Member
Avatar

Joined: 08 Aug. 2005
Location: Mukwonago, WI
Status: Offline
Points: 961
Post Options Post Options   Thanks (0) Thanks(0)   Quote uglyjeep Quote  Post ReplyReply Direct Link To This Post Posted: 06 May 2007 at 5:33pm
Scott, if you find your core is unrebuildable, drop me an email, I have a used one here that I can check to see if its OK, and send to you for just the postage cost if you need it.  Let me know, thanks!
Daniel
Back to Top
dclear View Drop Down
Member
Member
Avatar

Joined: 12 July 2006
Location: Milwaukee, wi
Status: Offline
Points: 927
Post Options Post Options   Thanks (0) Thanks(0)   Quote dclear Quote  Post ReplyReply Direct Link To This Post Posted: 07 May 2007 at 3:44pm
I rebuilt mine, and the bore was rather "on the edge" but it does not leak.  Just be sure that all the pieces are in the kit you rebuilt with.  Last winter I went through all sorts of gyrations due to a missing part in the rebuild kit that I failed to notice, or, thinking stupidly, that it's absence was an "upgrade."
 
You don't get much wiggle room on these cast iron parts.  OTH you cant always depend on new parts--they sometimes are junk from the factory.  I'd trust Daniel--you can hone them out, and a hand drill operated hone is not all that expensive.
 
You win, you win.  You lose, You lose.  I think it's worth a try.  You can always start over with new, and there is really not much hassle in replacing a MC if you dont mind wrinkly paint.
 
del clear
del clear











Together we can figure it out, after all, it's only a machine, if a man can build it, a man can fix it. {Author: bkruetz}
Back to Top
Scott R View Drop Down
Member
Member
Avatar

Joined: 16 Mar. 2007
Location: Gaines, MI
Status: Offline
Points: 1387
Post Options Post Options   Thanks (0) Thanks(0)   Quote Scott R Quote  Post ReplyReply Direct Link To This Post Posted: 10 May 2007 at 4:32pm
Daniel, Thank you very much! I just might take you up on that offer.
 
Once I get a couple hours of down time I'm going to look a little further into the one I have.


Edited by Scott R - 11 May 2007 at 4:42pm
Michigan Flat Fender Club on Facebook

1949 CJ2A #221621

1965 CJ-5
Back to Top
p3ferris View Drop Down
Member
Member
Avatar

Joined: 22 July 2005
Location: Norfolk Nebraska
Status: Offline
Points: 3629
Post Options Post Options   Thanks (0) Thanks(0)   Quote p3ferris Quote  Post ReplyReply Direct Link To This Post Posted: 10 May 2007 at 6:38pm
I rebuilt mine.  Never done one before and I found out it is very simple.  They make a rebuild kit and a hone for doing it.  Way less than 60.00.
Ed
cj2a lefty
Back to Top
Scott R View Drop Down
Member
Member
Avatar

Joined: 16 Mar. 2007
Location: Gaines, MI
Status: Offline
Points: 1387
Post Options Post Options   Thanks (0) Thanks(0)   Quote Scott R Quote  Post ReplyReply Direct Link To This Post Posted: 11 May 2007 at 4:54pm
Where is a good place to buy a rebuild kit?
 
I looked at Walck's and they list a Master Cylinder Repair Kit for $9.95
 
 
Seems awful cheap.... would this have all the goodies for a complete rebuild?
Michigan Flat Fender Club on Facebook

1949 CJ2A #221621

1965 CJ-5
Back to Top
sean View Drop Down
Moderator Group
Moderator Group
Avatar
Sponsor Member

Joined: 20 July 2005
Location: North Idaho
Status: Offline
Points: 7328
Post Options Post Options   Thanks (0) Thanks(0)   Quote sean Quote  Post ReplyReply Direct Link To This Post Posted: 11 May 2007 at 5:09pm
Got mine at NAPA for $14.95.

The same rebuild kit works in many older vehicles, so it's fairly common.


Edited by sean - 11 May 2007 at 5:10pm
Back to Top
p3ferris View Drop Down
Member
Member
Avatar

Joined: 22 July 2005
Location: Norfolk Nebraska
Status: Offline
Points: 3629
Post Options Post Options   Thanks (0) Thanks(0)   Quote p3ferris Quote  Post ReplyReply Direct Link To This Post Posted: 11 May 2007 at 6:18pm
Mine was 11.00 and some change
Ed
cj2a lefty
Back to Top
 Post Reply Post Reply
  Share Topic   

Forum Jump Forum Permissions View Drop Down



This page was generated in 0.172 seconds.