was just working on sister's 98 Civic 4dr LX AT

the brake light was on (I didnt realize the brake fluid was low. it was little bit above min. line)

I took out front wheels to check out the pads cuz she mentioned squeak. they were getting close to the indicator so I replaced them (had some new axxis metal master laying around)

when I push the front right piston back in via a caliper piston compression tool (loan from pepboys) I forgot to took off the cap for the mastery cylinder..

I also pushed the brake a few times while I was trying to press the piston back in (had to push in and out) cuz the boot wasnt seating in properly.

after I finish the front right, I went to the front left.

by this time the piston was out extensively on the front left caliper.. it also looks like the dust boot has somehow came off? I tried to seat the boot back on.. and piston was actually dangling around (I was like wtf?) then as i try to push the piston back in/reseat the dust boot.. the dust boot came out from the caliper somehow, and brake fluid came pouring out via the piston area.

while cursing up a storm and getting fluid everywhere.. (and air into the system).. I reseat the dust boot somehow (or at least I think its back in) and got the piston back in the caliper.. while fluid comes out as I press piston back in..

now I gotta bench bleed the system.. to get the air out.. but I'm not even sure if the caliper is okay. fluid shouldnt come out like that, even if the dust boot falls off. nor should the piston felt loose like that. is the piston seal somehow compromised?

that might be why the fluid level is low.. its been leaking slowly, and when I take off the pad and gave more room for the piston to travel, its now pouring out by the dozing via some leak.

anyways I know this is super long and i apologize for it, but I just want to give as much detail as possible. I'm not sure what the problem is, I still havent got a chance to bleed the system yet since its all dark now. i'll be doing that tomorrow while looking at the caliper piston again.

any suggestions/help would be greatly appreciated. I dont want my sister to be stuck without a ride.

edit: oh i forgot to mention. of course the pedal feel is soft now (brake barely works).. and when engine is on and when I depress the brake, I hear hissing of air leak around master cylinder.. that wasnt there before I think. but its there now. I put the cap back on tightly, so I duno whats wrong.

ack. i doubt my sister wants to spend the money on an enitre brake system overhaul, but there's so many problems.


Modified by CapYoda at 9:34 AM 3/27/2005


Modified by CapYoda at 11:22 AM 3/27/2005

 

I dunno man, I think something i screwed up in that caliper if you have fluid coming out of the piston area. I would look into a new caliper. You can probably buy one used for around 50$. Or check autozone, they have cheap calipers too.

 

i thought about it more, and I think it could simply be because I didnt take off the reservoir cap..

so this did a few thing maybe:

1. piston is completely unseated cuz caliper was left dangling while i depress brake pedal.. (no pads for the piston to press again, so it pooped out) and probably ripped the piston seal (or that happened when I try to push piston back in) piston wasnt out completely (like fell off) but it was quite loose.

2. while i push piston back in.. the mastery cylinder cap is still on.. excessive pressure (although I would think brake system can handle more press than what I can dish out via the piston compression tool) broke some seal or compromised MC, hence hissing around from that area. or leak in some seal, or hose..

so I think, worse case scenario:

1. caliper rebuilt or buy a new/rebuilt caliper.. I dont really feel like rebuilting the caliper. even if the rebuild kit is only like $18 bux.. it'll be messy and I gotta grab an air compression tool.

2. master cylinder rebuilt or buy new/rebuilt MC. this isnt worth the rebuilt I think, so I might get a new one..

both I think I can exchange old part for core refund..

sigh. its been so long since I did a brake job that, I forgot a lot of important steps. end up costing more just from a simple swap job.

best case scenario? caliper is still good, I wont require new one.. the fluid just magically leaked out and not due to my negligence.

MC doesnt need to be replaced.. all i need to do is to bleed complete system and it'll magically fix everything!



Modified by CapYoda at 9:23 PM 3/27/2005

 

ttt?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by CapYoda &raquo;</TD></TR><TR><TD CLASS="quote">1. piston is completely unseated cuz caliper was left dangling while i depress brake pedal.. (no pads for the piston to press again, so it pooped out) and probably ripped the piston seal (or that happened when I try to push piston back in) piston wasnt out completely (like fell off) but it was quite loose.
</TD></TR></TABLE>
thatll do it. just rebuild the caliper since its allready this far. its not too hard.

 

Just go exchange that caliper for a reman at auto zone/advance/napa. Put it on and bleed the entire system.

 

hmm I just checked out the front left caliper again.. and it seems to be working? its not loose, nor is it leaking anymore... piston goes in and out firm..

any chance its still okay? lol.

I'll bleed the system, and see if pedal firms up. and if brake works.

I cant pinpoint where the hissing noise is at. i guess it could be brake booster? or the MC. i duno.

i dont think i have time to get new caliper today.. so might get that exchange later.

thanks for suggestions.

 

you blew the seal on the piston out because you did the brake job improperly.

NEVER EVER EVER PRESS THE PEDAL WITH NO PADS IN THE CALIPER. thats what blew the seal.

you do not have to remove the master cylinder cap to squeeze the piston back in, just open the bleeder valve on the caliper. thats the proper way to do it. squeezing the piston with the bleeder closed can also damage any number of seals in the brake system. its very unlikley but its possible.

you may be OK but you should definatley rebuild the caliper for saftey.

 

yeah the piston seal is probably gone.. hence massive fluid leak.. its not leaking anymore.. but I duno.

I totally forgot the piston wasnt against a pad on the driver side..

autozone has a remanufactured one for good price, but its not in stock so imma have to order it and exchange my core another day.

gonna bleed entire system now just to get pedal feel back.. cuz there's still air in the system.

gonna have to get a longer wrench too cuz some of those bolts are 80+ lb.ft of torque i think.. to remove the caliper.

um anything i should watch for when removing the caliper? I know i should bleed the system again regardless if I seal up the brake line or not. any tips on that?

thanks for input.

 

just be mindfull of the brake line when removing the caliper, make sure you dont twist it too much or dangle the caliper by it.

 

okay thanks.

ill be getting that in as soon as the new caliper comes..

I've just finish bleeding the entire system.. some pockets of air came out and the old dirty fluid came out.. the brake pedal is still soft and mushy though.

i still cant pin point where the hissing noise is coming from, the master cylinder or the brake booster. some vaccum leak is going on..

anyone else have any ideas on the hissing noise? I've been searching and it looks more and more like the brake booster..

 

well, for future reference if anyone searches this thread... master cylinder is fine.

I did more test.. and pinpoint it to the brake booster. checked vacum line/check valve and it was working fine...

during pedal testing the brake booster wasnt working fully proper. ie: when brake pedal is depressed and engine is turn on, the pedal does sink lightly, which means booster is functional.

BUT, on leak test.. when engine is off, and you pump/press the brake pedal... the brake pedal should gradually rise up and get firmer/harder.. that didnt happen. it kept being soft...

so yeah.

brake booster, for whatever reason, failed. I'm guessing something internal (pushrod of pedal to booster/mc?) broke some seal or sometthing, the brake fluids were all contaminated too.. (nice colors of blue and green!)

so yeah. booster was replaced with a rebuilt one and hissing noise from vaccum leak is gone..

brake works fine now.

also replaced rear shoes. cuz that's gone.

welp, finally fixed.

oh wait, still need to replace caliper. lol. I'll wait on that and observe it, but it probably needs to be replaced.