Brake Caliper Rebuild Questions

||Caroline wrote:
||> Thanks Rex, Eric, Mike, mrhct, and Jim.
||>
||> Due to negligence, my 1991 Civic didn't have its first brake flush until 3
||> years, 60k miles into its life. After this I wasn't much better, abiding
only by
||> the 30k mile requirement (again, due to negligence on my part). To date the
car
||> has had only 4 brake flushes in its 13 year life. Its due for its next this
||> month (July, 2004).
||>
||> I have never done my own brake flush. I have been studying up on it using
||> Autozone's repair guides, my Chilton's, and the UK (essentially helm) site.
I am
||> now prepping for a one-person gravity bleed and flush.
||
||gravity works great for fluid refresh if you don't have airlocks, but
||it's unreliable in a rebuild like this. borrow a neighbor kid for a few
||minutes and have them pump the pedal for you. just make sure they
||understand how important it is that they don't let their foot /off/ the
||pedal until you say! suckback is bad news.

Put a wooden block under the pedal

||> replacing the piston seal
||
||that bit's easy - small electrical screwdriver has that thing out in no
||time. the fiddliest item in the whole job is fitting the new boot, and
||even that's not too bad if you think about it before you start working.

I agree, you can do it.

||
||if you need to, you can replace the rear cylinders without removing the
||shoe assembly.
||
||if you want to tackle the rear shoes, that's not such a big deal.
||despite the fact that it's often sworn at as being difficult to
||reassemble, i promise, it can be done without brute force, skinned
||knuckles and special tools. simply attach the brake cable, screw the
||adjuster bar all the way back in, fit the main tension spring, and you
||can then "puzzle" that essembly back into position in one piece. then
||you can fit the lower spring by hand and puzzle that into position also.

The key to working on rear drums is to remove both drums, hose them off to get
rid of the dust, then work on one side at a time. That way you can look at the
other side if you get confused.

Texas Parts Guy

 

dudette, youre probably 4 brake flushes ahead of most 91 civics! i have
yet to give my 98 its second, but its only at 46k miles. i plan to very
soon though.

i got a mityvac kit at harbor freight... works great, 1 person. no pedal
pumping, which is what can screw up the master cylinder! start at the
far rear, then drivers rear, then pass front, then drivers front,
working your way to the master cylinder. by then, all the fluid should
be that nice straw color!

compared to what youve done so far, itll be a non-event. trust me.

or you can jack up the front, take the wheels off, and turn the rotors
by hand. then press the brakes and do it again. thatll tell you if one
side is sticking. youll feel it. some dragging is normal, but both
rotors should move ok.

 

dudette, youre probably 4 brake flushes ahead of most 91 civics! i have
yet to give my 98 its second, but its only at 46k miles. i plan to very
soon though.

i got a mityvac kit at harbor freight... works great, 1 person. no pedal
pumping, which is what can screw up the master cylinder! start at the
far rear, then drivers rear, then pass front, then drivers front,
working your way to the master cylinder. by then, all the fluid should
be that nice straw color!

compared to what youve done so far, itll be a non-event. trust me.

or you can jack up the front, take the wheels off, and turn the rotors
by hand. then press the brakes and do it again. thatll tell you if one
side is sticking. youll feel it. some dragging is normal, but both
rotors should move ok.

 

id go with the mityvac. its hard to say where exactly the ridge in the
master cylinder might be. itll come in handy reading vacuum and doing
other tests that require vacuum and/or pressure. its a fun tool!

 

id go with the mityvac. its hard to say where exactly the ridge in the
master cylinder might be. itll come in handy reading vacuum and doing
other tests that require vacuum and/or pressure. its a fun tool!

 

I'm not freakin' or sweatin' it, Curly and Mike. Just "coming clean" with my
automotive sins.

I saw quite a bit of commentary on the mityvac kits when googling the archives.
I'll look into this more tomorrow.

Aside: I discovered Harbor Freight two weeks ago. There's a store not too far
from me. It's for anyone interested in low price tools at not necessarily
Craftsman quality. I bought a 20 to 200 inch-pound Pittsburgh torque wrench
there for under $20 (on sale). I'm using it all the time. Compared it a couple
times to my larger, Home Depot Husky torque wrench (lower ranges). Works great,
though I realize it likely won't last as long (or hold calibration as long) as
something much more expensive.

'kay-doke.

Sounds good.

 

I'm not freakin' or sweatin' it, Curly and Mike. Just "coming clean" with my
automotive sins.

I saw quite a bit of commentary on the mityvac kits when googling the archives.
I'll look into this more tomorrow.

Aside: I discovered Harbor Freight two weeks ago. There's a store not too far
from me. It's for anyone interested in low price tools at not necessarily
Craftsman quality. I bought a 20 to 200 inch-pound Pittsburgh torque wrench
there for under $20 (on sale). I'm using it all the time. Compared it a couple
times to my larger, Home Depot Husky torque wrench (lower ranges). Works great,
though I realize it likely won't last as long (or hold calibration as long) as
something much more expensive.

'kay-doke.

Sounds good.

 

Update:

I did a "dry run" over the weekend and found that the three boots per caliper
were in pretty good condition, after all. After more study, I decided to
"rebuild" only the piston, replacing the piston seal, the boot ring, and the
boot. Majestic (online parts) had quite a delay, due to both the July 4 holiday
and because it didn't have all the OEM parts in stock, and so I ultimately
canceled an order I had with them (which they were very cool about). I called my
favorite independent shop, and they likewise didn't keep these parts but
suggested I use a Napa piston rebuild kit by United. I ended up using this kit.
$14 per piston, which is a lot less than OEM, though I note others' concerns
about material quality.

As you suggested, Jim, I raised the caliper and then used the brake pedal to
increase the brake fluid pressure. Slowly, with a lot of checking, I pushed the
piston out far enough that I could wobble it a bit with my fingers as it sat in
its boot. When the caliper was off and at the workbench, I ended up pounding a
bit (going through the banjo bolt hole with a wooden dowel). To novices: Beware
the close tolerance of the piston in the cylinder. Don't "pound hard" anything
on the caliper.

With the electrician's screwdriver (thin, small diameter) I probed around the
piston boot an hour or so trying to figure out how everything went together. I
found the metal of the boot ring beneath the gunky buildup near the
circumference. I soon found I could pry the boot ring up and out easily. The
boot ring seems just a little thicker and just a little stiffer than baling
wire.

On the next caliper, this all went a lot faster, of course.

Which grease to buy was puzzling for a few days. My Chilton's manual says to use
"silicone grease" on the pins on which the caliper "floats" and "cylinder
grease" on the piston seal. Plenty of silicone greases are in the hardware and
auto parts stores, but I went with a synthetic grease dedicated to brake
calipers, like I think Jim cited with his link. $2 for a generous packet at
Autozone. It's red in color. It said it could be used on pistons, too, so, fed
up with the conflicts in my research on this issue and what the stores were
selling, I used the red Autozone synthetic grease on the pins and a very thin
film of it on the piston seal, along with brake fluid, for the required
lubrication.

The piston seal was no problem installing. The piston went back in place pretty
easily, with a little help from a C-clamp. A little fidgeting got the boot and
boot ring into place pretty easily, too.

I cleaned up the three sleeves with a degreaser followed by a thorough water
rinse and let them dry. I wiped down the two pin (= bolt) assemblies, applied
the red caliper grease, and re-assembled all.

After studying reports on the MityVac vacuum pump for brake bleeding, I happily
splurged on the super-duper MityVac kit at Harbor Freight. (I"m on a "buy only
really nice tools" kick, anyway. Plus, like Mike said, I can use the MityVac for
vacuum tests elsewhere on my car's engine.) Using a vacuum to pump out the brake
fluid at each wheel made a lot of sense to me. So too does not operating the
brake pedal, at some risk to the master cylinder. All as Mike and others in the
archives have suggested.

In hindsight, I don't know how I could have achieved as thorough and controlled
a flush as I think I did without the MityVac kit.

I goofed once and I think dropped the level below the bottom of the Master
Cylinder reservoir. "Gulp" sound at the reserovoir? Big mistake. I was going to
do a more thorough flush anyway and so pretty easily recovered from this
mistake. Naturally, you test the car's brakes thoroughly before going out on the
roads. After the "gulp," the pedal went just about to the floor and wouldn't
"lock," so I knew I'd probably injected an air bubble into the system.

The MityVac fittings worked great on the front caliper bleeder valves but not so
well on the rear ones. Consequently, vacuum was harder to hold on the rears, and
a lot more air bubbles came through the Mityvac hose for the rears. Undoubtedly
this was from the ambient air leaking through the fitting and not the brake
fluid in the car's system. The car's braking fine, so I am not worried.

Jim, I removed the brake drums from the rear brakes, cleaned off the inside
parts with brake cleaner, and got a good look at the cylinders and what all is
going on in there. I've got plenty of shoe left (by the specs for the car) and
figure that most of the braking power comes from the front, anyway. Thus I'm
holding off replacing the rear brake cylinders until I need another pair of rear
brake shoes. (The car's on its second pair of rear brake shoes at 154k miles.)

Hose pinchers (= clamps) were a vital part to this job, as Jim suggested. After
more study, I ended up with a pair from Autozone for $7 or so. They operate like
little vises and did the job perfectly. I could not locate anything like what
Jim cited online at any of the Auto parts stores or hardware stores, though I
would have preferred the clamps he suggested. Easier fastening and releasing...

In hindsight, and as several here suggested, I'd say anyone on a tight budget
worried about his/her car's brakes and reasonably mechanically inclined could
probably get away with just cleaning up the sleeves, pins (= bolts), and piston
boot, and boot ring. From the pistons I carefully scraped off a tiny bit (but
just enough to resist motion, I figured) of residue, too. Re-grease with
synthetic caliper grease, bleed, and you're back on the road.

"Must have" tools and materials for this job to me are:
Medium-large C-clamp
Hose pinchers (= clamps)
Mityvac kit
Brake cleaner (read what it can go on and what it can't)
Brake fluid
Jack stands, one pair
Lotta cardboard to lay on the ground and on the car where you're doing the work.
Brake fluid eats paint.

As always, I appreciate the various nudges in the right direction folks provided
here. All responses were helpful to making decisions on this.

 

Update:

I did a "dry run" over the weekend and found that the three boots per caliper
were in pretty good condition, after all. After more study, I decided to
"rebuild" only the piston, replacing the piston seal, the boot ring, and the
boot. Majestic (online parts) had quite a delay, due to both the July 4 holiday
and because it didn't have all the OEM parts in stock, and so I ultimately
canceled an order I had with them (which they were very cool about). I called my
favorite independent shop, and they likewise didn't keep these parts but
suggested I use a Napa piston rebuild kit by United. I ended up using this kit.
$14 per piston, which is a lot less than OEM, though I note others' concerns
about material quality.

As you suggested, Jim, I raised the caliper and then used the brake pedal to
increase the brake fluid pressure. Slowly, with a lot of checking, I pushed the
piston out far enough that I could wobble it a bit with my fingers as it sat in
its boot. When the caliper was off and at the workbench, I ended up pounding a
bit (going through the banjo bolt hole with a wooden dowel). To novices: Beware
the close tolerance of the piston in the cylinder. Don't "pound hard" anything
on the caliper.

With the electrician's screwdriver (thin, small diameter) I probed around the
piston boot an hour or so trying to figure out how everything went together. I
found the metal of the boot ring beneath the gunky buildup near the
circumference. I soon found I could pry the boot ring up and out easily. The
boot ring seems just a little thicker and just a little stiffer than baling
wire.

On the next caliper, this all went a lot faster, of course.

Which grease to buy was puzzling for a few days. My Chilton's manual says to use
"silicone grease" on the pins on which the caliper "floats" and "cylinder
grease" on the piston seal. Plenty of silicone greases are in the hardware and
auto parts stores, but I went with a synthetic grease dedicated to brake
calipers, like I think Jim cited with his link. $2 for a generous packet at
Autozone. It's red in color. It said it could be used on pistons, too, so, fed
up with the conflicts in my research on this issue and what the stores were
selling, I used the red Autozone synthetic grease on the pins and a very thin
film of it on the piston seal, along with brake fluid, for the required
lubrication.

The piston seal was no problem installing. The piston went back in place pretty
easily, with a little help from a C-clamp. A little fidgeting got the boot and
boot ring into place pretty easily, too.

I cleaned up the three sleeves with a degreaser followed by a thorough water
rinse and let them dry. I wiped down the two pin (= bolt) assemblies, applied
the red caliper grease, and re-assembled all.

After studying reports on the MityVac vacuum pump for brake bleeding, I happily
splurged on the super-duper MityVac kit at Harbor Freight. (I"m on a "buy only
really nice tools" kick, anyway. Plus, like Mike said, I can use the MityVac for
vacuum tests elsewhere on my car's engine.) Using a vacuum to pump out the brake
fluid at each wheel made a lot of sense to me. So too does not operating the
brake pedal, at some risk to the master cylinder. All as Mike and others in the
archives have suggested.

In hindsight, I don't know how I could have achieved as thorough and controlled
a flush as I think I did without the MityVac kit.

I goofed once and I think dropped the level below the bottom of the Master
Cylinder reservoir. "Gulp" sound at the reserovoir? Big mistake. I was going to
do a more thorough flush anyway and so pretty easily recovered from this
mistake. Naturally, you test the car's brakes thoroughly before going out on the
roads. After the "gulp," the pedal went just about to the floor and wouldn't
"lock," so I knew I'd probably injected an air bubble into the system.

The MityVac fittings worked great on the front caliper bleeder valves but not so
well on the rear ones. Consequently, vacuum was harder to hold on the rears, and
a lot more air bubbles came through the Mityvac hose for the rears. Undoubtedly
this was from the ambient air leaking through the fitting and not the brake
fluid in the car's system. The car's braking fine, so I am not worried.

Jim, I removed the brake drums from the rear brakes, cleaned off the inside
parts with brake cleaner, and got a good look at the cylinders and what all is
going on in there. I've got plenty of shoe left (by the specs for the car) and
figure that most of the braking power comes from the front, anyway. Thus I'm
holding off replacing the rear brake cylinders until I need another pair of rear
brake shoes. (The car's on its second pair of rear brake shoes at 154k miles.)

Hose pinchers (= clamps) were a vital part to this job, as Jim suggested. After
more study, I ended up with a pair from Autozone for $7 or so. They operate like
little vises and did the job perfectly. I could not locate anything like what
Jim cited online at any of the Auto parts stores or hardware stores, though I
would have preferred the clamps he suggested. Easier fastening and releasing...

In hindsight, and as several here suggested, I'd say anyone on a tight budget
worried about his/her car's brakes and reasonably mechanically inclined could
probably get away with just cleaning up the sleeves, pins (= bolts), and piston
boot, and boot ring. From the pistons I carefully scraped off a tiny bit (but
just enough to resist motion, I figured) of residue, too. Re-grease with
synthetic caliper grease, bleed, and you're back on the road.

"Must have" tools and materials for this job to me are:
Medium-large C-clamp
Hose pinchers (= clamps)
Mityvac kit
Brake cleaner (read what it can go on and what it can't)
Brake fluid
Jack stands, one pair
Lotta cardboard to lay on the ground and on the car where you're doing the work.
Brake fluid eats paint.

As always, I appreciate the various nudges in the right direction folks provided
here. All responses were helpful to making decisions on this.

 

After studying reports on the MityVac vacuum pump for brake bleeding, I happily

Re: Mityvac,

Which one did you get? I checked Harbor Freight and they had 3..
$29, $33, $50.. What's the difference between them? It looks like
the diff between the 29 and 33 is that the $33 has a gauge, but I
also saw the $50, and didn't see much of a difference except the case,
and that it might be metal..??

Thanks

Randall Fox

 

After studying reports on the MityVac vacuum pump for brake bleeding, I happily

Re: Mityvac,

Which one did you get? I checked Harbor Freight and they had 3..
$29, $33, $50.. What's the difference between them? It looks like
the diff between the 29 and 33 is that the $33 has a gauge, but I
also saw the $50, and didn't see much of a difference except the case,
and that it might be metal..??

Thanks

Randall Fox

 

Randall,

I bought #2068, priced at $53.99 I agree the difference between it and #39522
(priced at $33.99) is the fact that the more expensive one has the case and is
some kind of metal.

From googling I think a lot of people are quite happy with the $33.99 or lower
version. I'd say the version I bought is an extravagance. Maybe the super-duper
one will last a bit longer but if one only wants to bleed brakes, the plastic
pump may easily last many years.

I drove a bit farther today and my brakes feel just a bit mushy. I will try to
bleed a little more air tomorrow, hopefully with some sort of improved fitting
for the rear brake bleeder valves.

OTOH, the ride is noticeably quieter and smoother (both with the brakes applied
and not applied) than I remember.

 

Randall,

I bought #2068, priced at $53.99 I agree the difference between it and #39522
(priced at $33.99) is the fact that the more expensive one has the case and is
some kind of metal.

From googling I think a lot of people are quite happy with the $33.99 or lower
version. I'd say the version I bought is an extravagance. Maybe the super-duper
one will last a bit longer but if one only wants to bleed brakes, the plastic
pump may easily last many years.

I drove a bit farther today and my brakes feel just a bit mushy. I will try to
bleed a little more air tomorrow, hopefully with some sort of improved fitting
for the rear brake bleeder valves.

OTOH, the ride is noticeably quieter and smoother (both with the brakes applied
and not applied) than I remember.

 

||> >After studying reports on the MityVac vacuum pump for brake bleeding, I
||> >happily splurged on the super-duper MityVac kit at Harbor Freight.
||snip
||> Which one did you get? I checked Harbor Freight and they had 3..
||> $29, $33, $50.. What's the difference between them? It looks like
||> the diff between the 29 and 33 is that the $33 has a gauge, but I
||> also saw the $50, and didn't see much of a difference except the case,
||> and that it might be metal..??
||
||Randall,
||
||I bought #2068, priced at $53.99 I agree the difference between it and #39522
||(priced at $33.99) is the fact that the more expensive one has the case and is
||some kind of metal.
||
||From googling I think a lot of people are quite happy with the $33.99 or lower
||version. I'd say the version I bought is an extravagance. Maybe the
super-duper
||one will last a bit longer but if one only wants to bleed brakes, the plastic
||pump may easily last many years.
||
||I drove a bit farther today and my brakes feel just a bit mushy. I will try to
||bleed a little more air tomorrow, hopefully with some sort of improved fitting
||for the rear brake bleeder valves.

#07000 includes a brake bleeding kit.
Includes a fluid feeder to keep the MC full automatically while you are under
the car sucking (sorry, couldn't resist).
It also includes a bottle to catch the fluid before it gets to your Mityvac.

Alternately, you can use a common jar, with tubes epoxied into the lid.
One tube goes to the bottom and attaches to the tube that goes to the brake
nipple.
The other just goes through the lid and attaches to the Mityvac

#06000 is just the brake bleeding accessory kit.

#07205 brake bleeding accessory Kit kit has a molded silicone tip that snaps
over a brake bleeder nipple. The kit costs as much as you probably paid for your
gun, but I don't see that particular tip listed as a separate service item.

And Mityvac recommends using teflon tape on the threads to prevent air being
sucked in around the threads and giving you false readings. I highly recommend
doing this. Not only does the fluid come out in a solid stream, it reduces the
amount of pumping. It also eliminates the possibility of a seized bleeder screw
in the future. Just be careful not to get the tape near the tip.
..
Texas Parts Guy

 

||> >After studying reports on the MityVac vacuum pump for brake bleeding, I
||> >happily splurged on the super-duper MityVac kit at Harbor Freight.
||snip
||> Which one did you get? I checked Harbor Freight and they had 3..
||> $29, $33, $50.. What's the difference between them? It looks like
||> the diff between the 29 and 33 is that the $33 has a gauge, but I
||> also saw the $50, and didn't see much of a difference except the case,
||> and that it might be metal..??
||
||Randall,
||
||I bought #2068, priced at $53.99 I agree the difference between it and #39522
||(priced at $33.99) is the fact that the more expensive one has the case and is
||some kind of metal.
||
||From googling I think a lot of people are quite happy with the $33.99 or lower
||version. I'd say the version I bought is an extravagance. Maybe the
super-duper
||one will last a bit longer but if one only wants to bleed brakes, the plastic
||pump may easily last many years.
||
||I drove a bit farther today and my brakes feel just a bit mushy. I will try to
||bleed a little more air tomorrow, hopefully with some sort of improved fitting
||for the rear brake bleeder valves.

#07000 includes a brake bleeding kit.
Includes a fluid feeder to keep the MC full automatically while you are under
the car sucking (sorry, couldn't resist).
It also includes a bottle to catch the fluid before it gets to your Mityvac.

Alternately, you can use a common jar, with tubes epoxied into the lid.
One tube goes to the bottom and attaches to the tube that goes to the brake
nipple.
The other just goes through the lid and attaches to the Mityvac

#06000 is just the brake bleeding accessory kit.

#07205 brake bleeding accessory Kit kit has a molded silicone tip that snaps
over a brake bleeder nipple. The kit costs as much as you probably paid for your
gun, but I don't see that particular tip listed as a separate service item.

And Mityvac recommends using teflon tape on the threads to prevent air being
sucked in around the threads and giving you false readings. I highly recommend
doing this. Not only does the fluid come out in a solid stream, it reduces the
amount of pumping. It also eliminates the possibility of a seized bleeder screw
in the future. Just be careful not to get the tape near the tip.
..
Texas Parts Guy

 

glad it worked out ok!

regarding refitting the pistons, they should slide back in with just
thumb pressure. the important seal points are the outer face of the
cylinder groove and the piston wall. the groove is hard cast iron &
difficult to mess up if you're using a scraper - one that's not too
scratchy anyway. this means you can scrape out /all/ the accumulated
oxidation & gunk in the cylinder without too much fear. likewise, the
piston is forged & hard chrome plated. it too is fairly wear resistant,
so the flat blade of a larger blunt screw driver makes a great scraper
to get these things clean. [try not to drop it tho - can bash up the
piston wall quite badly if it improbably happens to land exactly square
on the only flinty surface for miles around.... ]

when all that's done, and the seal/piston are lubed up, it should slide
back in without any significant resistance.

regarding lube, yes, brake fluid is the recommended lube if you don't
have silicone handy - it contains rubber preservatives as well as being
slippery. BUT, it's also highly corrosive in the presence of water. if
you're living in a wet or snowy climate, this'll show itself by rusting
the piston solid. this is why good quality boots/seals are vital and
the silicone is so useful. spread a thin film on the cylinder wall both
above & below the seal. then spread a thin film on the piston before
insertion. [which is how you discover not to drop them.] as the piston
slides in, the lube scrapes off the piston at the seal and completely
fills the gap. this and a thin film on the sealing surface of the boot,
ensures the brake fluid is as sealed as possible from moisture ingress
and hence not as likely to corrode.

 

glad it worked out ok!

regarding refitting the pistons, they should slide back in with just
thumb pressure. the important seal points are the outer face of the
cylinder groove and the piston wall. the groove is hard cast iron &
difficult to mess up if you're using a scraper - one that's not too
scratchy anyway. this means you can scrape out /all/ the accumulated
oxidation & gunk in the cylinder without too much fear. likewise, the
piston is forged & hard chrome plated. it too is fairly wear resistant,
so the flat blade of a larger blunt screw driver makes a great scraper
to get these things clean. [try not to drop it tho - can bash up the
piston wall quite badly if it improbably happens to land exactly square
on the only flinty surface for miles around.... ]

when all that's done, and the seal/piston are lubed up, it should slide
back in without any significant resistance.

regarding lube, yes, brake fluid is the recommended lube if you don't
have silicone handy - it contains rubber preservatives as well as being
slippery. BUT, it's also highly corrosive in the presence of water. if
you're living in a wet or snowy climate, this'll show itself by rusting
the piston solid. this is why good quality boots/seals are vital and
the silicone is so useful. spread a thin film on the cylinder wall both
above & below the seal. then spread a thin film on the piston before
insertion. [which is how you discover not to drop them.] as the piston
slides in, the lube scrapes off the piston at the seal and completely
fills the gap. this and a thin film on the sealing surface of the boot,
ensures the brake fluid is as sealed as possible from moisture ingress
and hence not as likely to corrode.

 

||regarding lube, yes, brake fluid is the recommended lube

Actually, the recommended lube is Brake Assembly Lubricant.
The old Raybestos number was BSF12. It would be hard to find.
Texas Parts Guy

 

||regarding lube, yes, brake fluid is the recommended lube

Actually, the recommended lube is Brake Assembly Lubricant.
The old Raybestos number was BSF12. It would be hard to find.
Texas Parts Guy

 

Caroline, Rex,

Thanks for the info...

Randall Fox