urgent: snoop needs brake gurus asap

[snoopyloopy]

alright, so for awhile now, my brakes have had a bit of a problem and were kinda non-existant at times. which has increased lately. we're talking i'll be trying to back out the driveway and my brakes are on the floor. so yesterday, i decided to try to tackle the problem. i've had some ebc greenstuff pads and some ss lines sitting in my garage for the longest, so i changed both my front pads and the lines. but, problem definitely not solved. brakes used to be low maybe 1:5 times, now brakes are on the floor 1:3 times and the other two they're low. also pulls right under braking. i did go ahead and glance at the lines and all again, there's some fluid around the right one and i'm thinking i'm going to rerun that one for sure. but beyond that, anything else anyone would recommend checking or having a look at?

[russiankid]

I would suspect the MC has a leak.

[snoopyloopy]

i would too, but i don't see any evidence of there really being one. at least not externally, and the fluid level isn't dropping.

[Oldblueaccord]

what are the condition on the rear brakes ?


I agree that from what I have gathered here your mastercylinder can fail completely in these cars. I have not ever had that happen to me.

I am guessing the fluid is all new since you out new front lines on it.


wp

[snoopyloopy]

well i didn't completely flush it all so the fluid isn't all new. and actually, now that it's mentioned, i didn't bleed the back lines. if you gentlemen will excuse me, i have a little project to go work on...

[Oldblueaccord]

I know it sucks but pull your rear tires drums etc and see whats going on back there. The shoes must be very very close to the drums to work correctly. I adjust them so I can barely slide the drum on over the shoes and it is ver hard to remove the drum with out some work. You shuld still be able to turn the wheel over by hand but hear the brake "scratch" the drum as they turn.


wp

[russiankid]

I know it sucks but pull your rear tires drums etc and see whats going on back there. The shoes must be very very close to the drums to work correctly. I adjust them so I can barely slide the drum on over the shoes and it is ver hard to remove the drum with out some work. You shuld still be able to turn the wheel over by hand but hear the brake "scratch" the drum as they turn.


wp

A few hard hits with a hammer to the drum help getting it off.

[snoopyloopy]

mmhmmm, readjusted the new lines and bled the entire car this time, just marginally better now. but the front passenger line has a leak where it meets the steel line, so i'm thinking that's the problem for sure.

[Civic Accord Honda]

reminds me i need to inspect my legends brake system its going thu brake fluid like a caviler goes thu oil

[carotman]

The Master cylinder doesn't need to have evidence of failure to not work properly. What fails on those is the inner seal. You press on the brakes and they go to the floor. If you pump the brakes, it will work because you'Re building pressure in the system.

I'm sure that replacing the MC will solve your problem.

[snoopyloopy]

mmhmmm, damnit. at this rate, i might as well go ahead and put in my rear disks too. what's a good source for a new mc of good quality and low price?

edit: when i bleed the brakes, it builds up like it's supposed to like in the haynes manual. but then when the car is turned on for driving, effective braking power is at the floor or non-existent. i already noticed that one of the lines is leaking at the connection. any better ways to remedy that short of new lines altogether?

[wprocomp]

did you strip the threads on those line-I have been through some sets of those lines and never had any problems-I assume your using a flared wrench for them I hope-I would also replace the the MC because if all new lines and pads are not helping-which actually shouldnt make the pedal go down to the floor in the first place I would suspect the MC-how are the seals around the piston on the calipers?

[Oldblueaccord]

I bought the nissan MC from rockauto a while back. I have it it the box still have not used it but it seemed to be the correct factory looking MC 15/16 or whatever it is susposed to be. I think it was 65$ or 80$ I cant remember.


wp

[Legend_master]

The Master cylinder doesn't need to have evidence of failure to not work properly. What fails on those is the inner seal. You press on the brakes and they go to the floor. If you pump the brakes, it will work because you'Re building pressure in the system.

I'm sure that replacing the MC will solve your problem.

I 100% agree, gonna be the inner seal leaking on the master cylinder. Change out the MC and your problem is solved

[snoopyloopy]

I bought the nissan MC from rockauto a while back. I have it it the box still have not used it but it seemed to be the correct factory looking MC 15/16 or whatever it is susposed to be. I think it was 65$ or 80$ I cant remember.


wp

yeah, i saw that on there too. i saw cheaper ones there and elsewhere, but nissin is on a lot of the oem parts, so i'm gonna splurge on my life.

edit: i was looking at se-i ones since i plan to make my car se-i in brakes, and they have two for '88 lx-i: the one i found for the '89 se-i as well as another one. anyone know the difference? and i noticed the lx-i offerings were 15/16, where as se-i were 7/8. does it make that much of a difference?
NISSIN Part # 46100SM4J03 for the 89 se-i one
NISSIN Part # 46100SF9013 for the 88 lx-i one


did you strip the threads on those line-I have been through some sets of those lines and never had any problems-I assume your using a flared wrench for them I hope-I would also replace the the MC because if all new lines and pads are not helping-which actually shouldnt make the pedal go down to the floor in the first place I would suspect the MC-how are the seals around the piston on the calipers?
no, lines aren't stripped. i made sure i avoided that wonderful (not!) part. but yeah, one of the lines is actually leaking, but i went ahead and teflon taped it just to see if that would help. not leaking as much anymore. although i think i might just invest in a complete set of lines.

[markmdz89hatch]

be careful with that teflon tape as I'm not sure if the brake fluid will eat it. brake fluid has the tendency to eat damn near everything it comes in contact with including paint, and rubber gloves (which is very annoying).

Anyway, as for the lines, did they come with copper washers? Where are they leaking? (ie. Where the braided line mates up with the hard line, or at the caliper itself?)

[Oldblueaccord]

Yeah I think above it correct there should be cooper crush washers on some of the joints I know for sure on the calipers and they must be the correct size and thickness. The chinese ones are wrecking havok on mopar guys. They flooded the market with too thin washers and they won't crush enough to give a good seal. I can't remember if there are washers on the ones from the body lines to the flex but I think there are.

As far as the MC sizing it gives you differant pedal feel,travel, and with the SE-i conversion I can not remember which way it goes if 7/8 is firmer or not then the 15/16. There some good write ups on this I think Sport comapct car did one about 5 years ago before they completely went to shit. I think the one I bought was new not rebuilt is why I paid the x-tra.
EDIT:
http://www.moparaction.com/tech/archive/disc-main.html

What to do if your car doesn't have a power booster? Simple. Forget it! Unless you have a 5,000-pound wagon, you'll do just fine without it. You can tailor the pedal pressure to your liking by playing with master cylinder diameters. Smaller cylinder = less pedal pressure required. Larger cylinder = ”harder” pedal, less travel.



wp

[russiankid]

If you have a leaking line I would be careful driving. You don't want the line to give out completely. I have Raybestos brake lines all around and no issues with them.

[snoopyloopy]

Yeah I think above it correct there should be cooper crush washers on some of the joints I know for sure on the calipers and they must be the correct size and thickness. The chinese ones are wrecking havok on mopar guys. They flooded the market with too thin washers and they won't crush enough to give a good seal. I can't remember if there are washers on the ones from the body lines to the flex but I think there are.

As far as the MC sizing it gives you differant pedal feel,travel, and with the SE-i conversion I can not remember which way it goes if 7/8 is firmer or not then the 15/16. There some good write ups on this I think Sport comapct car did one about 5 years ago before they completely went to shit. I think the one I bought was new not rebuilt is why I paid the x-tra.
EDIT:
http://www.moparaction.com/tech/archive/disc-main.html

What to do if your car doesn't have a power booster? Simple. Forget it! Unless you have a 5,000-pound wagon, you'll do just fine without it. You can tailor the pedal pressure to your liking by playing with master cylinder diameters. Smaller cylinder = less pedal pressure required. Larger cylinder = ”harder” pedal, less travel.



wp
so basically, the 15/16 mc would be slightly firmer in feel than the 7/8 cylinder since it's .0625" bigger. and no, no crush washers or anything, and i did reuse the washers at the calipers, but, there's no leaking at the calipers. only leaking around the threads of right front hardline-ss brake line.


be careful with that teflon tape as I'm not sure if the brake fluid will eat it. brake fluid has the tendency to eat damn near everything it comes in contact with including paint, and rubber gloves (which is very annoying).

Anyway, as for the lines, did they come with copper washers? Where are they leaking? (ie. Where the braided line mates up with the hard line, or at the caliper itself?)
yeah i was weary of it eating the teflon tape but i was looking at other lines and they were teflon-lined so i figured they'd be ok taped. and yeah, i've trashed so many pairs of nitrile gloves it's not even funny. and no, i bought the lines from a member here who said he'd never installed them, but all i received were the six lines, nothing else. and it's leaking from where it meets the hardline from the body. right around the threads. but i've gone ahead and just ordered a new set of techna-fit lines, so we'll see what happens with both of them.

[markmdz89hatch]

If it's leaking at the hardline connection, I'm 99% sure there's no washers or anything there as those hardlines are flared fittings, so as you tighten the line nut, they're supposed to seal themselves. ...good to know now that the brake fluid won't eat teflon. It might also help (if the teflon is brake fluid resistant) to back the nut off, slide it up the hardline a lil bit, then teflon the back of the flare, push the nut back over it, then re-snug the nut to the soft lines. Good luck.

[snoopyloopy]

yeah, so it turns out the master cylinder was the culprit. new mc, brakes are hard as a rock now. better even than when i bought the car last year. and also, the teflon tape at the corner isn't leaking, although i bought a new set of techna-fit lines just in case. put the ss lines in the back too so now i have complete ss lines all around. thanks guys for the help! :thumbup:

[codyJDM]

Did you go with a 7/8's or a 15/16's MC? good to hear you got your brake issues cleared up, I need to take care of mine as well :uh:

[snoopyloopy]

i went w/ the 15/16 nissin from rock auto. took some pix too, i'll post a thread when i get off my ass.

[MessyHonda]

yeah same thing was happening to me...i changed it out with a napa part and now its solid like a rock. i love the technafit lines

[snoopyloopy]

yeah i'm mad now though i can't heel-toe in corners. brake pedal is too high and i end up pressing too hard.