This is the adjuster at the
bottom of the backing plate, in it's place on my car after the
frame and brake system restoration.
You can see the two piston
halves nearly touching as these are new brake shoes and there is
no outward adjustment needed yet.
That was the day before I
took the car. These pictures below were 125 miles later.
Notice the two "missing" studs?
Luckily there was no real
damage to the new aluminum drum, but you can see the aluminum
shavings on the wheel cylinder and shoes.
Not the best tapping job that
I've ever seen.
This is why I suggested
saving your originals as described below.
I've
accumulated several old backing plates that had the original
Girling wheel cylinders and adjusters intact.
To remove these without snapping off the studs, I soaked them
heavily with Kroil and allowed it to loosen
the nuts and then I put the plate in a vise and slowly and
evenly applied pressure on the wrench to remove them.
So once you
get everything off, it's time to clean up the messy parts and
take them all apart for rebuilding.
For now, I'll focus on the adjusters and leave the wheel
cylinders for another day.
Thanks to a
great tip that I picked up on the 6-Pack Forum from a regular
aka TR6Harris, the process
begins with a 30 hour soaking in a plastic tub with a sealing
lid, as this does start to stink when the
CLR and water mix starts to eat at the grease and rust that has
accumulated on these parts over the past 35 years.
The tub on
the left is ready to be emptied of the parts soaking in it and
the dirty ones on the right will be added to a fresh
60/40 mix of CLR and water. Depending on your
parts condition the time and mix ratio may need to be longer or
weaker.
*****PLEASE
NOTE THAT THIS IS AN ACID BASED PRODUCT AND PROPER EYE AND HAND
PROTECTION*****
MUST BE USED ALONG WITH ADEQUATE VENTILATION AND GOOD COMMON
SENSE.
As you
could see above, the mix was rather dirty, so it was time to
dispose of it responsibly and add the new mix.
But first,
these are the parts that I'm going to clean up. I was
move, if you have the time, is to remove the grease first, but I
was lazy and wanted to see how long it took with a slightly
stronger normal mix (rather than the normal 50/50 ratio).
OK, so here
we go. I cover these well, but do NOT seal the lid all the
way, as it seems that the mix expands the air as it cleans.
*****PLEASE
NOTE THAT THIS IS AN ACID BASED PRODUCT AND PROPER EYE AND HAND
PROTECTION*****
MUST BE USED ALONG WITH ADEQUATE VENTILATION AND GOOD COMMON
SENSE.
I was busy,
so I didn't bother to look at these for 30 hours and I was
pleasantly surprised when I peeked into the dirty solution.
*****PLEASE
NOTE THAT THIS IS AN ACID BASED PRODUCT AND PROPER EYE AND HAND
PROTECTION*****
MUST BE USED ALONG WITH ADEQUATE VENTILATION AND GOOD COMMON
SENSE.
I washed the parts in HOT water
and scrub them with a toothbrush to remove all of the acid from
the soaking and any
other crud that is hanging on, even after all of that chemical
action.
The wheel cylinders can wait
for another time, so let's get started on the adjusters.
Disassembly is easy, IF the
parts are not frozen up from rust, corrosion and old grease
inside.
The CLR will help get rid of most of it, but at times a soaking
of a stubborn unit in Kroil (strong penetrating oil) is
required.
This guy needed another 10
hours of soaking before it would allow me to remove the pistons
and screw out the adjuster bolt.
You first remove the pistons
by pushing them out of the adjuster bolt by turning the back and
forth until they come loose.
The adjuster bolt is turned clockwise down into the bore of the
cylinder and you use the octagon faced front edge to finish it
out.
When the pistons and the
adjuster bolt are out, you can see how it works and why they
freeze up, but we have the cure for that.
The beveled edge on the screw
has eight faces on it and you can feel a click sensation when
you adjust the brakes. This allows
the piston faces to each sit on a flat surface as there are
pushed further out in the bores to move the shoes closer to the
drum face.
Even though these soaked in
the CLR/Water mix, I still additionally cleaned them with a brass brush wheel
on my bench grinder.
So here we go with the empty
adjuster housing. I always tap the threads on parts like
these to be sure the parts go back in easily.
I run the tap through the
back side first to the front and then from the front to the back
to be sure it's all clean and working smoothly.
That is a 3/8" X 24 Tap with
a little CRC Cutting Oil on it, to bring out the chips if any
are made and to make the threads smooth.
And it looks like there was
some crap in there. That screw was a little tight coming
out, so this should help later.
The next step is running it
back through from the front side after removing that junk BEFORE
winding the tap out the back.
Now it's time to take care of
the screws on the piston. Part of these are exposed when
the shoes are new and over the years
rust, salt and road grime, would get into the threads and make
them hard to turn. If these would have been cleaned and
serviced at the time of every brake job, it may have lessened
the build up of corrosion that leads to the locked up problems.
Again, I am now using a 3/8"
X 24 Die to clean up these threads with a little cutting oil.
This will insure a good fit.
A little blast with brake
cleaner and some compressed air to clean everything out and
we're ready to go back together.
I am a big fan of Anti-Seize
and this is a perfect spot for it. I will put it on all of
the threads because we are using dissimilar
metals and if it has to come apart, you want it to be easy.
But by doing so, this will allow it to work for more years that
originally.
The adjuster screw goes in
first with a liberal amount on the threads. I use Q-Tips
to spread it around and Nitrile gloves are good too.
At a certain point you will
not be able to turn this from the front, which is OK as the
square end is now seen out of the back.
The difficult time is taking
these apart if the threads are dirty inside and you have those
last few turns to go to get it out of the front.
Just another view to show how
it should look. This has to go down a lot further to allow
the beveled pistons to fit in against the tip.
You can also see that the
inside of the bores are clean of all corrosion and build up.
After all of these years, there will be stuff in there.
OK, so this shows the other
end, with the adjuster screw bottomed out to show the threads
through the back.
The mounting threads are
cleaned and will get new SS washers and nuts and Anti-Seize as
well. These are 1/4" X 28 Fine Thread.
Before I get into assembling
the pistons, this is a fairly good piston after soaking in a new
batch of CLR mix for over 12 hours.
It still needs a better
cleaning on the wire brush to get is down to bare metal as shown
below on the right.
Now it's time for the
Anti-Sieze again and a nice coat will insure lots of lube and no
rust build up for many years to come
This is just for
illustration, but you need to cover the entire surface and the
bores of the housing.
That is where the Q-Tips come in
handy.
This shows the proper
alignment of the beveled edges to get them against the adjuster
screw properly.
And here we have it, all
done, with the slots lined up where the shoes can fit if
properly. I slid these back out and added
more A/S after I looked at the picture and saw the ends were not
completely covered. Again, the Q-Tip works well for touch
up.
I found out the hard way that
these will slide right out and on to the floor, which may
requiring cleaning and new A/S,
so to keep things together a new elastic on each one does the
trick of keeping them together until you are installing them.
You can also see how far in
the screw went, but that position will probably come back out
with new shoes on the car.
Lastly after some thread
chasing on the mounting studs and some Anti-Seize, I installed
new SS lock washers and 1/4" X 28 nuts.
A final view of the front and
these are ready for installation and many miles of trouble free
use. It would not hurt
to run a bead of the Anti-Seize around the big raised area between the
two studs where it fits into the backing plate.
That is a rust on contact area and makes
it hard to get them out.
What could
you do differently? I don't think much, except to add Nyloc
nuts to the studs and that would probably be a help.
It's time
to throw a plug to my friends at Alexander Racing Enterprises,
who make a nice tool for these adjusters that has an end that
fits the oil pan and differential plugs as well. It is
bent to get into the adjusters easily and will make a nice
addition to your tool box.
ARE- The Vintage
Racer
It's a nice
combination tool that does a good job which a regular open end wrench is
not bent to do.
Happy
Motoring!!!
|