Brakes for Beginners
By Jeremy Whitehead
First let me qualify this article by stating that
I'm no expert here. I'm simply a amateur mechanic who would like to share some
recent experiences with other novices in hopes they might decide to tackle
what really isn't too hard of a job. Brakes are one of those things that we
all tend to overlook until there's a serious problem with them. In my own
case, I recently came down out of the mountains only to find that my already
spongy pedal went clear to the floor this time and liked to scared me half to
death. I got lucky in that we weren't going very fast at the time and I was
able to grab the emergency brake and downshift enough to get the car stopped.
A near miss, but enough to wake me up to the fact that I needed to do
something - and quick. On the Spitfire, I decided to have Barry Rosenberg do a
serious brake upgrade (Wilwood calipers, GT6 rotors, braided steel lines, and
an uprated Master Cylinder). While this was perhaps a bit of overkill, I
thought it prudent to make sure that brakes would no longer be a weak link.
In this article however, we will deal more with my recent experience
with TR6 front brakes. My father in law, Jon Fry owns an early TR6 that is
pretty well bone stock. When he recently heard the metal on metal grinding
noise that makes the pit of your stomach cringe, he decided that it was about
time to look into his braking system. The TR6 brakes are rather a simple
affair and actually most Triumph brakes are rather similar in design. Jon's
car uses the Girling Type 16P calipers which are pretty much your basic dual
piston calipers. In Jon's case, nothing had been done to the car brake wise
since he purchased it, so we really didn't know how far we were going to get
in to it. Since the front brakes do about 80% of the braking job, we decided
to just tackle the front brakes and leave the rear's alone for the time being.
It can help to make things go a whole lot smoother if you've lined up
all your parts ahead of time. Rotors, Caliper rebuild kits, Caliper pistons
LMA Brake fluid, Brake Pads, Brake Clean and other assorted parts are all
readily available through the catalogs or local suppliers if you have them in
your area. Most Auto Zone's and the like will look at you dumbfounded like if
you show up asking for Triumph brake parts, but you can try if you like.
You'll need a can of standard grease, some 1/2 drive sockets, a few open ended
wrenches, screwdrivers and needle nose pliers, but most folks have this stuff
already so this really can be done by amateurs. A pencil (small) chisel can
come in handy as you'll find out later. An impact gun (air or electric) can
come in handy, but isn't really necessary. A good size bag full of old rags
would also be a good item to lay nearby as you're sure to be reaching for
them. LMA brake fluid is something that I've heard debated back and forth ever
since I got into this hobby. LMA just refers to the type of fluid it is and
some will say that it's an absolutely necessary item to keep from eating the
rubber seals in your British brake system. I've heard it both ways and really
have no opinion on the matter. LMA isn't that much more expensive than regular
brake fluid and you can get if from most British supply houses so why not?
Just whatever you do…don't mix it or any brake fluid with Type 5 silicone
fluid. Use either one or the other…not both. The two do not play well
together.
Jon got a really good deal on brand new rotors that made it almost a no
brainer when it came to turning his old rotors or just installing new ones.
For those of you that don't know, "turning" a rotor refers to taking your
rotors to an auto parts store or machine shop and having them shaved down so
that the braking surface is perfectly flat on each side. Since your brake pads
press up against the rotor in order to generate stopping force, a perfectly
flat surface is really an advantage. If you've ever driven a car whose brake
pedal pulsates and makes the whole car vibrate when applying the brakes, you
know what I mean. Pulsating or vibrating brakes usually result from a rotor
that has gotten too hot and actually warped. Other times, rotors can simply
rust , become grooved or get pitted thereby reducing the effectiveness of the
rotors. In any case, "turning" or machining down the rotors will true them up
and give you a good, flat surface for your pads to press against. Of course,
if the rotors have been machined once or twice before, they can become too
thin to machine again must be replaced. The minimum thickness rating is
usually stamped on the rotor hub and usually, I've found that the auto parts
store or machine shop can measure them and tell if you they can be turned
again. In this case, as I said earlier, Jon got a good deal on new ones so we
decided to just replace them.
When I arrived at Jon's house on Saturday morning he already had the
front wheels off the car and had removed one caliper already. He discovered
something that I'm sure is pretty similar on most TR's. When he went to unbolt
the caliper, he just reached around back and assumed that the four bolts he
found right off the bat were the ones he needed to remove. Well, as it turns
out, the four bolts that he had located were the four bolts that held the two
halves of the caliper together. Suffice to say that these didn't actually need
to be removed. Once you separate the two halves, there's a small o-ring in the
center that will need to be inspected for damage and perhaps replaced. It's an
easy mistake to make and not a big deal The caliper is actually held on by two
large bolts that hold it securely to the vertical link. Crane your neck around
back of the rotor with a trouble light and you'll see what I mean Removing
these two bolts are really all that is necessary. Once you've removed those
two bolts, the caliper and brake pads should just slide right off the rotor.
Now here's where you'll need to make a decision. If you're going to
rebuild your caliper, you can just disconnect your brake line from the caliper
and go set your caliper on your work bench. If you're not going to rebuild it
however, don't disconnect the line. Leave it connected to the caliper and just
support the caliper on the lower A-arm or a block of wood so that it's not
pulling on your rubber brake hose. How do you determine if you need to rebuild
the caliper? Well, first off, take a look at the rubber dust seals and see if
they're cracked or stiff. Another good idea would be to inspect the brake pads
and check for wear. If one brake pad has significantly more wear on it than do
the rest, it probably means that one of your caliper pistons is sticking and
your brakes have been dragging. Time to rebuild the calipers. In Jon's case,
the dust seals were shot, so we decided to go ahead and rebuild the calipers.
Rebuilding calipers is actually a bit easier than perhaps it might sound.
First, once we had removed both calipers, we pulled off what was left of
his dust seals got them out of our road The caliper rebuild kits that you can
purchase from just about any supplier come with directions that say you can
use compressed air to blow the pistons out of the calipers. Given that we're a
couple of rank amateurs without the necessary equipment to do this, we decided
to drive them out with a small chisel. Here again, you have a decision to
make. If you're planning on replacing the caliper pistons with new ones, you
don't need to be too careful with your old pistons. However, if you think your
pistons are in good shape and you might want to reuse them, then do this
carefully. Caliper pistons can easily add the better part of a $100 bill to
your total cost, but if they're pitted and rusty, I'd advise you to replace
them. We decided to go ahead and do the whole shebang while we were at it.
Driving the pistons out of the calipers proved to be more an exercise in
patience than anything. We mounted the caliper in a vise and used a small
pencil chisel to tap them out. There is a lip on the outside edge of the
piston that proved to be very helpful in getting these out. I tapped gently on
this lip around the piston forcing it out slowly but surely. Here again,
you'll want to be careful not to destroy this lip if you plan on re-using the
pistons.
Once you've got the pistons out, it's important to clean up the inside
of the caliper. First, take a rag and wipe out all the goo and other misc.
crud that has accumulated. Then take a look just inside the cylinder and you
should see a black rubber seal that is recessed into the cylinder. You'll be
replacing this, so take a small screwdriver and while holding your mouth right
and hopping and up and down on one leg, bunch up the rubber seal in one area
and force it out of it's groove. This is where a second pair of hands actually
comes in quite handy. By the fourth one, Jon and I had this down pat so don't
worry if you have a bit of trouble getting it out. Remember that you're
replacing it anyway so you don't have to be gentle with it. Just try not to
scratch up the inside of the cylinder while you're doing it.
Ok, once you got all remnants of the rubber seals and dust covers
removed, go back to cleaning up the cylinders. Make sure you clean up the
groove that you removed the rubber seal from and remove any built up deposits
of crud from the inside of the cylinder. I used a small bit of med grit
sandpaper to remove the stubborn bits and smooth up the inside of the
cylinder. You don't want pits or damage, so if it looks pretty rusty, you
might consider just replacing the whole caliper. However, if you get it
cleaned up and it's nice and smooth inside, now you're ready to start
replacing seals and pistons. The inner seal will go back in first. I coated
the seal in a bit of new brake fluid to help lube it up and ensure a proper
seal before I put it back in. Here again, a half dozen sets of hands can be
useful. The seal will look like it's too big around to fit in the cylinder,
but believe me, it will go in and fits nicely. You'll know it when you get it
seated right…it just sort of pops into place. Next, the outer dust cover will
need to be fitted. Read the directions that came with the caliper rebuild kit
to determine which sort of caliper you have and which step you need to do
first. On Jon's calipers, the dust seal went in first and once it was in
place, then you push the piston through the middle of it. This can be trickier
than it sounds and at least 4 hands were necessary to keep everything in place
when we did it. It really helps to coat everything in a coat of fresh brake
fluid as I described earlier. It helps to lube everything and keep it from
binding up while you're reinserting the piston. MAKE SURE you get that piston
lined up straight. It won't go in otherwise. It should be tight fit so don't
worry if it sticks a bit…you don't your brake fluid to run out all over the
place do you? On the early TR6 calipers the dust seal should fit right down on
that lip that you used to drive the piston out with. This was a bit tricky to
gently pull the edge of the rubber dust seal out and make sure it wasn't going
back down into the cylinder with the piston. We used a small screwdriver to
run around the outside edge and turn it back the right direction. You'll see
what I'm talking about..it looks pretty logical when you're doing it.
Once you've got all 4 pistons back in the calipers, you might want to
turn your attention to the brake bleeder nipples. This is an often neglected
area since it really doesn't do a whole lot, but if that 7/16" fitting is
rounded off from years of use, now would be the time to replace it. They're
cheap and real easy to replace so why not do it at now that it's convenient.
That's pretty much it for the calipers. Go ahead and put your new brake pads
in and fit the pins that hold the pads in. Make sure you force the pistons
pretty well as far back in the caliper as they'll go since you've got to get
the caliper, with the new brake pads installed down over that rotor. We used a
C-Clamp to push the pistons back in as far as they'd go. This is also how
you'd do it if you were JUST replacing your brake pads. Remember, I told you
NOT to disconnect the brake lines if you weren't replacing your calipers? This
is so that you won't have to bleed them when you're done. Just force the
pistons back in with the C-Clamp, put the new pads in and reinstall the
calipers over your newly turned or brand new rotors and you'd be done. It's
really quite easy if you don't have to rebuild the calipers.
One other thing to check is that rubber or cloth covered brake hose .
Make sure that aren't cracked, stiff or checked. If you see small cracks in
the rubber, REPLACE IT. Now's the time to do it and if one of those things
springs a leak, you probably won't have much in the way of brakes. They always
seem to spring a leak when they're under pressure and that's usually when that
big Buick has just pulled out in front of you. This is a safety issue
here…don't skimp if your rubber lines are cracked.
In any case, now you're ready to tackle the rotors. TR6 rotors are
behind the hubs so you'll have to remove that little bell shaped metal dust
cap in the center of the hub to get to the castle nut underneath. This was a
tad tricky until I got out the chisel again. Rather than try to pry the lip of
the dust cap out away from the hub, I stood the chisel up at a parallel angle
to the front shocks and hit it two or three times with a hammer. After two or
three medium licks, I rotated it 90 degrees and hit it a few more times with
the hammer. Using the chisel allowed it get to get a bit of "bite" into the
dust cap that a standard screwdriver didn't have. Keep rotating the hub and
hitting it with the chisel and hammer till you've got it worked out. Unless
you've already bought a replacement, don't destroy this thing because you're
got to re-use it. Once you've got the dust cap off, then remove the cotter pin
that keeps the castle nut from turning. You'll know why I call it a castle nut
after you've seen it.
This is where I broke out the tool of all tools. The electric impact
gun. This is very similar to an air powered impact wrench but obviously it's
powered by electricity. Now let me state something here on the use of this
tool. It's got it's purpose, but I mainly used it to take stuff off with. DO
NOT USE IT TO RE-TIGHTEN the castle nut that holds your front hub assembly on.
It's a powerful tool and also a good way to destroy the front axel bearings.
I'm serious folks…don't hold me responsible if you strip a nut or destroy
something with one of these. They're awesome for removing stubborn bolts that
haven't been off for a while, but they'll twist a small bolt in half if you're
not careful.
Anyway, once you've removed the castle nut and the thick washer behind
it, you'll need to reach in and pull out your outer wheel bearing. Remember
how it came out. This should be packed in heavy grease. If it's not, you've
got a problem. While you've got it in your hand, inspect it for wear and
damage. All the little wheels should turn freely and be nice and round without
flat spots on them. Check the bearing for play and make sure it goes round
without binding or a gritty feeling. Once you're done playing in the grease
and spinning your wheel (bearings) put that aside and go ahead and pull the
rest of the hub assembly off. You'll notice that there's another (inner) wheel
bearing on the inside. Check it for wear as well. By now you've noticed that
the rotor came off with the hub. There's four bolts that hold it onto the hub.
Now's where that impact wrench came in real handy. Unbolt those four bolts and
remove the rotors. You can now either take the rotors out to have them
machined or simply install the new ones. It's a good idea to use a bit of
brake clean available from any auto parts store and clean any cosmoline off
them unless you really like the smell of burnt cosmoline for the first couple
hundred miles.
Once you've got the new rotors on, put the hub assembly back on the car
taking care to remember to put the bearings back in place the same way they
came out. I'd recommend packing some fresh grease in the hub as well as the
bearing. You don't want it squirting out around the edges, but you also don't
want them dry either. Put the bearing in the cup of your hand and press the
grease in the bearing till you hear the air bubbles popping out. If you're too
squeamish to play in the grease, get your wife to do it…I'm sure she won't
mind. Be sure to wipe a bit of the grease on your forehead and cheeks so it
looks like you've worked hard. Once you've got the hub with both wheel
bearings and the washer fitted back on to the axel put the castle nut back on
and tighten it down. DON'T OVER TIGHTEN. Remember what I said about NOT using
the impact wrench here? You don't need to be He-Man here and crank this down
so it'll never come off again, but you also don't want it loose. Just nice and
snug see? Locate the hole for the cotter pin and reinstall it. Bend it back so
the castle nut can't turn off and then put the dust cap back on.
You're in the home stretch now, so go grab your calipers with the new
brake pads in them and put them back down over the rotors. Take care to line
up all the dust shield brackets and brake line brackets the way the came off.
Put the bolts back in the holes and then reattach your brake lines. You can
tighten up the calipers AFTER you get the brake lines put back in. It just
makes it a little easier to do is all. Ok…now is where you'll need two folks
again unless you've purchased one of those nifty one man brake bleeders.
They're pretty nifty if you're doing this by yourself, but if you've got an
assistant, the old way works just as well. Fill up your master cylinder which
is by now empty and then have one person set in the car. Have them pump the
brakes and then push down the pedal all the way and hold it all the way down.
You probably won't have much of a pedal at first. Once they're holding the
pedal all the way down, open the bleeder screw on one side and release the
air. Close the bleeder screw again and repeat the process. After a few times,
you'll see fluid coming out along with air. Check the fluid level in the
master cylinder and keep repeating this until you've gotten all the air of the
lines and you're just getting brake fluid with no air bubbles. We put a small
length of rubber hose on the end of the bleeder nipple running down into an
old coffee can to keep the mess to a minimum. You can use whatever works best
for you. Once you're sure you've gotten all the air bled out of the system,
then top of the master cylinder and recheck all your lines and bolts to make
sure you didn't forget to tighten any. You can now put your wheels back on the
car and let it down off the jack stands. You're done.
I would advise you to go easy on your brakes till you get them broke it
(a couple hundred miles should be enough). The pads will actually need a small
amount of seat time before they work REALLY well, but you should have pretty
good brakes to begin with. I'll tell you from experience to back out of the
garage CAREFULLY the first time having your hand on the emergency brake when
you do. If somehow, you've left a line loose or not bled them properly, you
don't want to back out of your garage and into your neighbors new Lexus. Take
it around the block the first time rather gingerly to make sure you've got a
good pedal feel and that they're going to stop you when you need them. Like I
said, go easy on them for a short while to allow them to break in properly for
the first couple hundred miles or so.
Believe it or not, but disc brakes really haven't changed all that much
in the last 40 years. I just did the brakes on my '99 Hyundai Elantra the
other evening. They were actually a bit simpler and easier to do. I had the
whole thing done in an hour and a half so once you've done it once or twice,
you can save yourself some money and hopefully apply what you've learned here
to your everyday car as well.
Good brakes are something that should not be neglected. There's
absolutely nothing worse than that feeling when you push the pedal down and
nothing happens. Spend a little quality time with you car now and you'll never
regret it. Happy Motoring!
Georgia
Triumph Association Technical Articles