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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? |
#2
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Abeness > wrote in :
> 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. -- TeGGeR® The Unofficial Honda/Acura FAQ www.tegger.com/hondafaq/ |
#3
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TeGGeR® wrote:
> *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. [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. |
#4
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Abeness > wrote in :
> > 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... Do electrons have mass? > three cheers for the physics of vacuum! Thanks > again for awesome instrux. You're turning me into a reasonable > approximation of a brake dude. > 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. -- TeGGeR® The Unofficial Honda/Acura FAQ www.tegger.com/hondafaq/ |
#5
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TeGGeR® wrote:
> Abeness > wrote in : > > > >>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... > > > > Do electrons have mass? I doubt it. Should've written "gold coins". ;-) > I just changed my Master Cylinder. It got old and started leaking due to > worn-out seals. New pages soon! Lots of photos! 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> |
#6
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Abeness > wrote in :
> TeGGeR® wrote: >> Abeness > wrote in : >> >> >> >>>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... >> >> >> >> Do electrons have mass? > > I doubt it. Should've written "gold coins". ;-) > >> I just changed my Master Cylinder. It got old and started leaking due >> to worn-out seals. New pages soon! Lots of photos! > > 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. 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... > > 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. 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/...eal-remove.jpg Some probing revealed that this leakage had not risen to the point where it had got inside the booster itself. > Maybe I'll let it go for a while... Fix it now. Neglect can cost you. It's easy. Really. -- TeGGeR® The Unofficial Honda/Acura FAQ www.tegger.com/hondafaq/ |
#7
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Abeness wrote:
> TeGGeR® wrote: > >> Abeness > wrote in : >> >> >> >>> 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... >> >> >> >> >> Do electrons have mass? > > > I doubt it. Should've written "gold coins". ;-) > >> I just changed my Master Cylinder. It got old and started leaking due >> to worn-out seals. New pages soon! Lots of photos! > > > 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. *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. > > <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> |
#8
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TeGGeR® wrote:
> Abeness > wrote in : >>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. Replaced the caliper yesterday, and the parking brake now works correctly. Excellent! A few comments/additions to Tegger's excellent tips. > 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 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). > 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 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. > 5) Flip old copper washer over, and install banjo bolt and hydraulic line > onto new caliper. My OEM reman caliper came with new washers (2, one for each side of the connector). > 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. 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... > 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. 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. |
#9
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Abeness > wrote in :
> TeGGeR® wrote: >> Abeness > wrote in : > >>>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. 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. <snip> > Replaced the caliper yesterday, and the parking brake now works > correctly. Excellent! Congratulations! Other than the learning experience, it WAS easy, wasn't it? Next time you'll be 4 times faster. <snip> > 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 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. > 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. 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). <snip> > 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. 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. > 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. 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. <snip> > > 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... Because BOTH pistons are now contributing to retardation efforts. > > 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. It's silicone-based. You can't use petroleum greases because they wuill destroy the neoprene. > > Thanks again, Tegger, for being generous with your expertise. Much > appreciated. That's what Usenet is for isn't it? -- TeGGeR® The Unofficial Honda/Acura FAQ www.tegger.com/hondafaq/ |
#10
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TeGGeR® wrote:
>>>Abeness > wrote in : >> >>>>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. > > > > > 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. 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. > Congratulations! Other than the learning experience, it WAS easy, wasn't > it? Next time you'll be 4 times faster. For sure! > 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. Tried to do all that. Would have been easier to get it right with another set of hands, I suspect. > 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). Good idea. > 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. 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. > 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. 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. >>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... > > > > Because BOTH pistons are now contributing to retardation efforts. 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. >>Thanks again, Tegger, for being generous with your expertise. Much >>appreciated. > > > > That's what Usenet is for isn't it? 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. |
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