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Brake Master Cylinder rebuild - 64 D100 318

Posted: Tue Dec 08, 2009 8:55 pm
by jeb2086
Gents,

getting back to my 64 D100 w/poly 318. current project is brake master cylinder. opted to rebuild since new one is $140+ (napa).
don't know what the previous owner had in mind but the master cylinder rubber is in shambles. got rebuild kit at napa. contents: 5 pieces

this may be an easy one for you but I need a logic check on proper re-assembly. Basically the kit came with pieces that weren't in the one I took apart. Wondering on little stamped metal piece that goes on end of spring. Orientation? does spring orientation matter? One end is slightly smaller than other. I also got a flat rubber washer. not sure where this goes. I can make a good guess but would rather not.

any help appreciated and pics are even better. I can provide pics of what I have also.

additionally, I cleaned the cylinder up with a soft brass wheel on dremel (nylon didn't cut it) but don't know how abrasive is too abrasive.

thanks,
Joe

Re: Brake Master Cylinder rebuild - 64 D100 318

Posted: Thu Dec 10, 2009 8:48 pm
by Hobcobble
Hi Joe,
Rather than re-doing my single reservoir brake master cylinder, I
opted to switch to a dual reservoir system. The dual master ran
me about $45 and all the lines, fittings, etc. were about $20.
DSCF0134.JPG
Its an easy job.
You might want to consider it.....
John :Thumbsup

Re: Brake Master Cylinder rebuild - 64 D100 318

Posted: Fri Dec 11, 2009 5:05 pm
by rd200
I just completed mine on the 65D200 should all be the same.
your rebuild kit should include

aluminum piston, washer, rubber cup, and rubber dust shield.

The rubber cup will go in the cyl large end in first. The washer will go in next. That will act as a brace for the piston. The spring will go in next, then the piston. You will then have to attach the backing plate with the dust shield to the back of the cyl using the two small bolts. You will want to buy a cheap break cyl hone to smooth out the inside of the master cyl. If it has any big pits it might not be able to be rebuilt. I had to buy a new one as mine kept sucking in air even with the new kit. You can test it out on a vise using a screwdriver as a simulated clutch pedal pushing in the piston after putting fluid in it. It should not leak from the back and should shoot fluid out in a good stream.

Good Luck....

Re: Brake Master Cylinder rebuild - 64 D100 318

Posted: Mon Dec 14, 2009 4:23 pm
by jeb2086
thanks guys,

from your description, I beleive I have the right kit. here's a link showing kit contents:

http://shop.oreillyauto.com/productdeta ... mber=MK376

Your order of assembly is a significant departure from how I found it but then again they were locking up after a minimal braking.

the dual resovoir sounds like a good contingency.

the I'll take a crack at the rebuild and let you know.

Re: Brake Master Cylinder rebuild - 64 D100 318

Posted: Thu Jan 21, 2010 8:49 am
by jarheadsgt
If you are working on a 64 brakes I need to know how do you remove the rear drums, mine are stuck and all I have managed to do is remove the axle, not what I was attempting to do there. also any ideas on the dual pot master and pix would be helpful, I am still waiting for my shop manual to show up :banghead

Re: Brake Master Cylinder rebuild - 64 D100 318

Posted: Thu Jan 21, 2010 11:48 am
by junior
Turn the adjusting screw from the inner window on the lower inner backing plate; turn until brakes close and the drum is easy to pull off. If still won't pull off,you may need a brake drum puller.Hope this helps.

Re: Brake Master Cylinder rebuild - 64 D100 318

Posted: Thu Jan 21, 2010 12:32 pm
by Hobcobble
jarheadsgt wrote:If you are working on a 64 brakes I need to know how do you remove the rear drums, mine are stuck and all I have managed to do is remove the axle, not what I was attempting to do there. also any ideas on the dual pot master and pix would be helpful, I am still waiting for my shop manual to show up :banghead
100 or 200 series?
John

Re: Brake Master Cylinder rebuild - 64 D100 318

Posted: Thu Jan 21, 2010 12:44 pm
by Hobcobble
Hobcobble wrote:
jarheadsgt wrote:If you are working on a 64 brakes I need to know how do you remove the rear drums, mine are stuck and all I have managed to do is remove the axle, not what I was attempting to do there. also any ideas on the dual pot master and pix would be helpful, I am still waiting for my shop manual to show up :banghead
100 or 200 series?
John
OK.... just read your other post on rims. Here's what you need to do.
As your axles are already out..... there is a 2 3/8" large nut that will
need to come off. There is a socket available at most parts stores
that is meant for this job. They are normally 3/4" drive but you can
just use a 3/4-to-1/2 adapter. Anyhow.... you must bend the "tabs"
of the lock washer away from this large outer nut before removing it.
Once you've got the outer nut off, remove the tabbed lock washer and
then the second large nut that is behind it. At this point, your drum is
ready to be pulled off. To ensure its easy removal, you might want to
adjust your brake shoes INWARD so the drum doesn't drag on them.
You might lose a bit of gear lube.... just so you know.

Some of these large axle nuts can possibly be a 2 1/4. I'm not sure
if they got as big as 2 1/2".... just take a measurement to confirm.
If the socket is out of the question, you might try to use a large pair
of channel locks or use a hammer and drift punch to CAREFULLY back
the nut off. :idea
John

Re: Brake Master Cylinder rebuild - 64 D100 318

Posted: Fri Jan 22, 2010 1:14 pm
by Jones
I'll chime in too...

Here is what used to get the drums off. It was made by a guy that I used to work with. If you're going to keep the original axle under the truck, you might want to consider having something like this to pull the drums.

:2cents
Keith

PS... Ignore the Poly in the background... :joker