replacing single rear brake caliper?

The last time I checked my rear brakes, they were fine but for the fact
that the parking brake arm rotates freely on the left side, without
engaging the piston. 94 Civic EX. The calipers show no evidence of brake
action problems: perfectly smooth in-and-out action on both rear
pistons--they even retract automatically when the brake pedal is
released. The evidence points to there being a break in the link between
the p-brake cam (which looks perfect on the top side, nice boot and
seal, no rust) and the piston, inside the caliper. Whether it's the pin,
sleeve piston, or adjusting bolt, I dunno--whatever it is, a reman
caliper is indicated.

So, I was planning to replace just the left rear caliper myself, but
decided to get a quote on having it done, whereupon I was told that they
do all such work in pairs for reasons of liability (and the guy didn't
have time to give me a quote if he wasn't guaranteed of the work--hah
hah--after quoting me $480 to do the exhaust from the cat on back).
Replacing brake stuff in pairs makes perfect sense where the calipers
are rusted out, or in the case of brake pads, but it really seems
unnecessary in this case--though I can understand the shop's policy.

Suggestions to the contrary?

 

*IF* the good caliper is in fact actually good, and *IF* BOTH old and new
pistons move in AND out with EQUAL ease, and *IF* you are certain that
water has not penetrated under the parking brake shaft seal, then replacing
just the one is probably OK.

The problem is that if one piston can move more freely than the other, your
brakes will pull differently, which can cause the rear of your car to yaw
slightly on braking. This can be a safety issue in wet or icy weather, but
no more so than if you had poorly-maintained brakes to begin with.

Me, I wouldn't cheap out like that. I'd replace both (which I've actually
done).

Replacing the caliper is easy as pie, if you want to do it yourself.
1) Remove cover from master cylinder. Wet upper lip of cylinder with brake
fluid, and smooth Saran Wrap over the open MC, making certain that there
are no folds or kinks that cross the lip. Pull the Saran taut, and secure
with a rubber band
2) Remove parking brake clevis pin, and remove clevis from parking brake
shaft
3) With brake cleaner spray, spray all dirt off the banjo bolt at the back
of the caliper, and remove the bolt
4) Have a pan under the caliper to catch the fluid that will drip out.
Fluid will drip until the Saran Wrap is slightly concave, then it will stop
5) Flip old copper washer over, and install banjo bolt and hydraulic line
onto new caliper.
6) Place a piece of wood to keep the piston from being able to be ejected
from the bore, and bleed with the caliper OFF the mount bracket.
7) Bleed as you normally would, but turning and rapping the caliper with a
nylon hammer every few strokes to shock air bubbles free.
8) Reassemble to mount bracket and put parking brake back together
9) Done!

Because of the complex internals, there are lots of little nooks and
crannies that can trap air bubbles and make them hard to get rid of.
Shocking the caliper while turning it different ways is the only way of
dislodging them.

Good luck.

 

[reposting cuz it looks like my newserver burped when I posted this last
night, and never let it through]

According to the repair history *summary* I got from the previous owner,
the rear calipers were replaced at 111,500 miles (ca. March 2004). I'm
now at 118K. I'll take another look to be absolutely certain, but I'm
quite sure that a caliper with only 6.5K miles on it (very few of them
snow/salt miles) has a long life ahead of it. Near as I can guess, the
left rear must've been defective from the start, as the p-brake wasn't
working on that side when I got the car at 113K--I just didn't realize
it was a serious problem for some months, when I had a chance to
investigate. Unfortunately, I don't have the repair receipts and the
shop is 40 miles away, so I wasn't about to pursue it for such a small item.

Tegger, the tips about the saran wrap on the master cylinder and the
wood to prevent piston ejection during bleeding are worth their
electrons in gold... three cheers for the physics of vacuum! Thanks
again for awesome instrux. You're turning me into a reasonable
approximation of a brake dude.

 

Never hear of replacing calipers in pairs... although it sounds like a
good idea from the shops perspective... LOL

Professor
www.telstar-electronics.com

 

Do electrons have mass?

I just changed my Master Cylinder. It got old and started leaking due to
worn-out seals. New pages soon! Lots of photos!

BTW, after a few complaints from some (dialup) readers, I'm going to be
reworking the pages (especially the ones with lots of photos) so the pics
are a lot smaller in size to make the pages load faster. You would then
click on the small pics to get the big ones. Currently the pics are full
size, but show up small until you click on them.

 

I doubt it. Should've written "gold coins". ;-)

Youdaman! I'm planning to replace my clutch master cylinder this summer.
If I find the digital camera a friend gave me a while back, maybe I'll
document the process and join the effort.

Truth is, though, I got the replacement maybe 6-8 months ago before I
ran out of time, and it hasn't failed yet. Not leaking seriously,
either, just a little. I don't have to add fluid, but there is some
fluid present around the rubber boot at the pedal side of the engine
wall. Maybe I'll let it go for a while... oil up my new parts a little
more so they don't rust... ahhh.

<rant>
Sears.com is a royal PITA. I finally ordered a floor jack (for store
pickup) and some new metric sockets. They cancelled the jack and two of
the other three items cuz they didn't have it at the store!
Unbelievable. They didn't think to change it to "ship from wherever to
the store". Duh. Now they're gonna call in 6-12 hours to discuss? Guess
I'll never do THAT again...
</rant>

 

Excellent. The nore the merrier. Usenet thrives on collective input,
individually gathered and presented, of course.

Since this was my first time, I made a few mistakes that cost some time.
Details to follow.

Main tip: Unbolt the MC from the booster FIRST, THEN undo the hydraulics.
And cover the alternator to keep crud from falling into it.

Also, move as many cables as far as possible out of the way and tie them in
place as far away as you can, using multiple zip-ties daisy-chained
together as needed. The more room you have to work in, the better.

And you may need to adjust the master cylinder pushrod after. This part is
a minor adventure.

Photos soon...

Leave it too long and the fluid will dribble into the booster and eat the
diaphragm. I found a tiny bit inside the "cup" of the booster. Whether or
not this was due to leakage through the rear seal I do not know.
http://www.tegger.com/hondafaq/misc/booster-seal-remove.jpg

Some probing revealed that this leakage had not risen to the point where it
had got inside the booster itself.

Fix it now. Neglect can cost you. It's easy. Really.

 

*do not* *do not* *do not* oil brake parts!!! it rots the seal rubbers
big time. if you want to use a lube, make sure it's a silicone lube.
and beware that "synthetic" is not necessarily silicone. "contains"
silicone is not good enough either. needs to 100% silicone.

 

Sil-Glyde (watch the spelling!) is OK and is readily available.

 

But crack the hydraulic seals first, otherwise you may have trouble
exerting enough force to break it loose with the MC unbolted.

 

i hate that stuff. it says it "contains" silicone, and may be fine for
assembly in non-critical situations, but my experience is that it reacts
with the kind of rubber it's [allegedly] ok to be used on [natural
rubber - nr] & quickly turns into a sticky brown gunge. i'd use tom
cats urine before using that filth ever again. used it on some sway bar
bushings. left the car standing for a couple of weeks, & when i went to
drive it again, it felt like the suspension was locked solid.
eventually stripped the sway bar bushings down again, & it /was/ locked
solid! had to use a big screwdriver to pry that mess apart so i could
clean up. could see where the nr had swelled - classic symptom of oil
contamination. had to replace the bushings again because after the
contamination, the polymers were still breaking down & kept sticking
themselves to the sway bars. nightmare. it may be fine for butyl
rubbers, like cv joints, but nr like bushings & brake seals? absolutely
no no no way.

 

I should have asked what Abeness wanted to keep from "rusting".

The caliper body is washed with either zinc yellow dichromate or that new
gray aluminum compound. Everything else is either rubber or Parkerized,
with the exception of the piston face and the parking brake mechanism.

I use Zip-Slip 100% silicone grease for internal seals and caliper piston
dust boots (which don't "rust"). The Sil-Glyde is used on external rubber
parts, such as slide pin boots (which don't "rust").

The advantage of Sil-Glyde is that it is substantial enough to resist
washing away under winter conditions. Pure silicone will disappear in days.
http://www.tegger.com/hondafaq/rustybrakes/moredetail/brakes2_detail.html


Abeness would be better to keep the parts indoors on an upper floor of his
house rather than attempt anti-corrosive measures.

 

*Clutch* master and slave cylinders; nothing to do with brakes, guys. It
seemed pretty clear to me that they were *very* lightly oiled on
arrival, but ISTR that we went through this discussion a while back and
I was probably informed that the factory coating was something special,
or whatever. I probably won't do more than stick the parts in a ziploc
bag after heating them very gently (i.e., very low heat) in the oven to
eradicate any moisture, as one might do with an iron skillet, though
lower temp.

 

You know I'm talking about the *clutch* master cylinder, right? I didn't
think that had a booster.

It looks like the clutch master will be easy, too. I may apply your
saran wrap trick, though I'll probably want to change the fluid as I did
with my brakes last year. Maybe it was done when the clutch was
replaced, maybe not... Man, I regret not having that repair history
every other week.

 

I do know, BTW, that petroleum doesn't go near rubber. Thanks for the
reminder.

 

You are? Oops! Guess I didn't read carefully enough. That's different.

Since the clutch has no booster, leaks only make a mess, nothing else. If
you don't mind the mess and the clutch re-engaging at lights, you can leave
it until the car is undriveble if you really have to.

The clutch master cylinder is even easier to deal with than the brakes. If
you're changing both master and slave, you will be unable to keep the old
fluid. Everything has to come apart.

Bleeding will be very easy, as you've only got a single, short, simple
circuit and no proportioning valve. Just rip it all apart and throw the new
stuff together. You won't have any trouble bleeding it.

 

Well, I do have the parts--both master and slave, actually, on the
dealer's recommendation last summer at my pre-purchase checkup, though I
don't see any obvious leaking at the slave (they wrote up $3000 worth of
work all told). Haven't pulled the boot off yet, though. Clutch isn't
re-engaging at lights yet--thanks for the info on what I might start to
see. I don't *really* want brake fluid dripping down my carpeting, so
will probably do it, and both at the same time.

I *am* a little suspicious of a shudder that seems new as I pull out of
a parked position heading uphill (my block), but hopefully that's simply
the result of a change in the action of my leg in easing the clutch out
that I can adjust. Clutch seems fully engaged when the pedal is out all
the way. Hope it's not starting to slip!

Okeedok, thanks. I sure am glad I got a Helm manual (great investment,
that) and found this group. Great help.

 

Replaced the caliper yesterday, and the parking brake now works
correctly. Excellent! A few comments/additions to Tegger's excellent tips.

Disconnect the parking brake lever return spring before attempting to
remove the pin--relieves the tension on the pin. Obviously, make sure
the parking brake is fully released (and that a front wheel is blocked).

I was unable to achieve a perfect seal with the plastic wrap on my
master cylinder reservoir--either my rubber band wasn't tight enough or,
more likely, I think, there was enough going on around the outside of
the lip (locking tabs in particular) that it dripped a bit until I
rolled up a paper towel (the cheap, not-so-absorbent kind) into a tight
cone and pulled it into the hydraulic line connector, which was
conveniently shaped something like a donut. That stopped the drip until
I was ready to connect the new caliper.

Do be sure that there's enough fluid in the reservoir that it doesn't
become empty, or you'll have to bleed the whole system instead of just
the caliper you're working on.

At this point, one removes the caliper body from the caliper bracket and
the old caliper bracket from the wheel. Remove the pad spring and
retainers and install them in the new caliper. Then install the new
caliper bracket, and attach the caliper body to the bracket temporarily
to ease attaching the hydraulic line.

My OEM reman caliper came with new washers (2, one for each side of the
connector).

The wood is critical (could also probably use a C-clamp, now that I
think about it). ;-/ I forgot to stick it in initially (can't believe
THAT), and while the bleed relief and maybe my slow pumping prevented
the piston from ejecting completely, thank goodness, by the time I
remembered, it was far enough out that I faced two problems:

1) My Lisle disc brake piston tool was too large to rotate between the
piston and the caliper body--it got hung up on the body; and
2) Screwing the piston (with adept manipulation of a needle-nose pliers)
did not retract it. Perhaps it had extended beyond the threads of the
adjusting bolt, I dunno. Of course there's all kinds of little bits in
there (see p. 19-31 in the Helm manual for a diagram), and I was
seriously worried that I'd managed to cause it all to come apart.

Thankfully, persistence paid off in the end. Between pushing and turning
the piston, I managed to re-engage and retract it, then finished
bleeding it, and everything appears to be working correctly. If you turn
out to be forgetful like me and find yourself wrestling with needle-nose
pliers, be careful not to damage the rubber piston boot: it's easy for
the pliers to slip.

Live and learn...

Worked for me. Several sets of bubbles emerged in the course of
turning/rapping. For some reason, the brakes feel slightly better after
replacing the caliper. Hmmm...

I'm a little concerned that the grease on everything (e.g. pins and cam)
*looked* like some of the petroleum greases I've seen, but I guess I'll
hope that since the caliper came right from Honda that the right grease
was used and I just don't know what it looks like.

Thanks again, Tegger, for being generous with your expertise. Much
appreciated.

 

Perfect! That's precisely what you want. Some time later I'll show you how
to keep them retracting that way. This involves a Lee Valley syringe and
some silicone grease.

Congratulations! Other than the learning experience, it WAS easy, wasn't
it? Next time you'll be 4 times faster.

That Saran MUST be 100% flat and sealed along the MC reservoir lip. Dirt or
wrinkles (even the tiniest specks) in the Saran will prevent a perfect
seal. You also have to wet the lip with brake fluid before laying the Saran
down, then stretch it tight.

There's another approach I've used in cars with a non-round MC: Get a very
small C-clamp (G-clamp to you Brits), and a couple of tiny squares of
cereal box board. Put a square of board on either side of the banjo bolt
and tighten the C-clamp over them. If you still get leakage, build up two
or three thicknesses of board on each side (stick the pieces together with
glue or tape).

Yep. You have to push hard to get it back to the screw threads again. You
have to push the fluid back into the MC. As somebody once suggested here
(Mike Pardee?), you can open the bleed screw to release the excess fluid
that way instead.

No way. No worries there. The ONLY thing you could ever have done is to
unscrew the piston off the adjusting screw. There is this amazingly strong
snap-ring deep inside keeping everything else together.

Actually, that's a way of doing a cheap-and-dirty rear caliper rebuild:
Simply unscrew the piston off the screw and remove it. Clean it off or
replace if rusty; replace the hydraulic seal; flush well with fresh brake
fluid and reassemble. Works well if the internal PB mechanism is still OK,
and saves having to get that inner snap-ring out.

Because BOTH pistons are now contributing to retardation efforts.

It's silicone-based. You can't use petroleum greases because they wuill
destroy the neoprene.

That's what Usenet is for isn't it?

 

Well, that was then and this is now... it appears that the pins on the
right side might be binding a wee bit--the wheel is a tad tighter on
that side, as I discovered when adjusting the p-brake afetr the caliper
replacement. Phooey. I wonder if it was just the left caliper that was
replaced at 111.5K miles. Man, I curse the day I didn't get the repair
history on this vehicle. Yet another example of just how critical it is
if you have any chance of getting it when you buy a used vehicle.

I gotta look into a drill attachment to aid in scouring out the holes
those pins slide into... come to think of it, I think I've seen files
that are designed for drills. Just have to be careful not to overdo it.

For sure!

Tried to do all that. Would have been easier to get it right with
another set of hands, I suspect.

Good idea.

Had done that, but it still took a hell of a lot of finagling to get
those screw threads to bite. I didn't have good leverage on the caliper
without the piston tool.

Thanks goodness. The p-brake is still working correctly after
vacationing. But now of course the clutch master is starting to feel
funny, as is the accelerator, and it appears that one cylinder is
missing a bit. More summer projects, it seems.

The regular brake seemed to be working on that side despite the p-brake
problem--at least, stepping on the pedal resulted in the piston pushing
out. Maybe not as vigorously. Oh well, all speculation at this point.

Absolutely. I'm a regular volunteer supporter in another forum (for
publishing software). I've learned so much from usenet over the years, I
can't help passing it on when I can.