Author Topic: Master cylinder disassembly?  (Read 2671 times)

ski

  • FOUNDING MEMBER
  • Senior Forum Member
  • *****
  • Posts: 117
    • View Profile
Master cylinder disassembly?
« on: August 22, 2008, 01:38:57 PM »
The diagrams I have seem to show a snap ring or "piston stop lock wire" that must be removed to get the "piston stop?" out and then the piston and rest of the inner parts.   I can't see this wire from the push rod end of the cylinder.  Any tips?  Does the stop have to be depressed inward to uncover the lock wire?  I tapped on it gently after soaking it with penetrant but I don't want to damage the unit.  Any help is appreciated.

ski 

Doug

  • FOUNDING MEMBER
  • Senior Forum Member
  • *****
  • Posts: 173
    • View Profile
Re: Master cylinder disassembly?
« Reply #1 on: August 22, 2008, 05:03:46 PM »
I rebuilt my mastercylinder a few monthes ago and it has a snap ring just inside the opening.

ski

  • FOUNDING MEMBER
  • Senior Forum Member
  • *****
  • Posts: 117
    • View Profile
Re: Master cylinder disassembly?
« Reply #2 on: August 22, 2008, 06:47:41 PM »
Okay that's what I thought but I couldn't see it even after cleaning.  Reason was it wasn't there.  Corrosion was holding the piston stop in after the M/C was separated from the push rod.  I cleaned it up and soaked it and the piston stop popped right out.  The last part to come out was a domed sheetmetal valve.  It was sideways in the bore after the stop popped out.  Does anyone remember if this goes in with the dome facing the spring or away from it?

ski

ski

  • FOUNDING MEMBER
  • Senior Forum Member
  • *****
  • Posts: 117
    • View Profile
Re: Master cylinder disassembly?
« Reply #3 on: August 22, 2008, 07:11:06 PM »
Correction.  The last piece to come out was a rubber washer.  From the marks on it I think the valve goes with the dome facing the spring.  The only piece in my kit I can't identify now is the larger rubber washer that appears to go in the pushrod end of the M/C?

ski

ski

  • FOUNDING MEMBER
  • Senior Forum Member
  • *****
  • Posts: 117
    • View Profile
Re: Master cylinder disassembly?
« Reply #4 on: August 22, 2008, 08:48:18 PM »
Okay I see where the bigger rubber washer goes.  Has anyone successfully unscrewed the master cylinder head and got it back on without wrecking it?

chetbrz

  • POC MEMBER
  • Senior Forum Member
  • ****
  • Posts: 1122
    • View Profile
    • My Space on the Web
Re: Master cylinder disassembly?
« Reply #5 on: August 23, 2008, 06:56:07 AM »
Okay Has anyone successfully unscrewed the master cylinder head and got it back on without wrecking it?

Ski,

I removed the rear piece but there really isnít any reason to do so.  There is nothing inside just empty space.  Make sure your return port is clear before you reassemble the Master cylinder.  Item 9 in the diagram.



I honed the cylinder and installed the kit.



 hope this helps,  ChetÖ
« Last Edit: August 23, 2008, 07:00:08 AM by chetbrz »
http://www.1948Plymouth.info           Web Master - Forum Administrator - AACA member

ski

  • FOUNDING MEMBER
  • Senior Forum Member
  • *****
  • Posts: 117
    • View Profile
Re: Master cylinder disassembly?
« Reply #6 on: August 23, 2008, 08:23:10 PM »
Chet, I just realized my picture is different than yours because my book is a 28.  I did not try to take the end off, what I thought to be a rubber gasket inside there was not.  Underneath the inlet fitting I have a hole about 3/16 that is wide open and an small orafice that I stuck a piece of .030 copper wire into.  The wire stops and I didn't force it.  Should this little hole be open into the cylinder area also?  I cannot see any light through it either.  My diagram although slightly different has a "compensating relief port" in that area. The bigger one is labled "secondary fluid port".

ski

Satillite70

  • Full Member
  • *****
  • Posts: 59
    • View Profile
Re: Master cylinder disassembly?
« Reply #7 on: August 23, 2008, 09:51:49 PM »
Hi Ski,
    I did mine a ouple months ago on my 28 Q 4door.  I took the end cap off, by heating the end cap with oxy/actelene torch till almost cherry, the quenching in cold water 3 times.  I with a bit of force, a vice and a very large channel-lock with came free.  There is an aluminum rind at the end with was corroded, and only visible once totally disassembled.  There were no welds holding mine together as there were with Chet's

Chris

chetbrz

  • POC MEMBER
  • Senior Forum Member
  • ****
  • Posts: 1122
    • View Profile
    • My Space on the Web
Re: Master cylinder disassembly?
« Reply #8 on: August 24, 2008, 02:48:08 PM »
Chet, I just realized my picture is different than yours because my book is a 28.  I did not try to take the end off, what I thought to be a rubber gasket inside there was not.  Underneath the inlet fitting I have a hole about 3/16 that is wide open and an small orafice that I stuck a piece of .030 copper wire into.  The wire stops and I didn't force it.  Should this little hole be open into the cylinder area also?  I cannot see any light through it either.  My diagram although slightly different has a "compensating relief port" in that area. The bigger one is labled "secondary fluid port".

ski

Ski,

That little hole should go clear through to the cylinder.  The hole is very small at the cylinder wall so maybe use high pressure air to clear it.  It is a bleed hole to allow the hydraulic cylinder to equalize on both sides of the piston.  I am not sure if you can see light through it but you should feel air flow when you apply air preasure. 

Chris,

That aluminum piece was the remains from the original valve.  This part is replaced by the kit (valve & rubber washer).  So it is no longer necessary.

My 2 cents,  Chet...
http://www.1948Plymouth.info           Web Master - Forum Administrator - AACA member

ski

  • FOUNDING MEMBER
  • Senior Forum Member
  • *****
  • Posts: 117
    • View Profile
Re: Master cylinder disassembly?
« Reply #9 on: August 06, 2014, 01:39:58 PM »
.....okay, like I was saying six years ago, I'm working on my brakes.  After a short break I now have two good front brakes with the rears capped off.  I was lacking a puller to get the rear hubs off but I got one off with a knocker type puller. The other side has funky threads and the knocker won't easily screw on to it.  It's new so the threads are sharp and want to cut their owned path. I have another knocker on the way that is old and worn.  I'm hoping it screws on easily like the retaining nuts do.  The knocker I used is 3/4 - 16 and I'm pretty sure it's correct. In the last few weeks I've also done the following:

got engine running fairly well
removed and cleaned oil pan & strainer
drained and filled transmission
drained & filled rear end
replaced repaired floor structure and parts of cab structure
replaced drive shaft discs
replaced fuel pump and regulators
rebuilt tillotson carb and carter DR-0

I took lots of pictures as I find it easier when I start putting things back together.  It was good to have for the drive shaft discs. I plan to post some with a description of what I did when I get the time but I hate typing. My immediate concern is brake pistons for the rear slave cylinders.  I need at least 2 and figure the other side will be bad as well. I also have a question on the master cylinder. Where does the rubber washer that fits into the bore of the master cylinder go?  Is it a cushion for the piston stop?   I installed it in that spot but took it out after thinking about it too long. I thought I had this worked out but I don't. There was one installed on the car when I got it because I had the old one in the bag with all the other old MC parts.  The brakes seem to work without it but that's just sitting in the garage.  I guess I should have been taking pictures six years ago when I took it apart.

ski

ski

  • FOUNDING MEMBER
  • Senior Forum Member
  • *****
  • Posts: 117
    • View Profile
Re: Master cylinder disassembly?
« Reply #10 on: August 06, 2014, 01:45:01 PM »
The rubber washer in question is on the left.