ok so i havent replaced my master cylinder yet... which i know may be my main problem, but i did go ahead and replace the front and rear brakes, and bleed them. so now the car stops a little bit but still no pressure on the pedal????? a friend who helped with the brakes says it may be the booster? any suggestions? before i replace the master cylinder... and should i bleed the lines again after i change the m.c.?

 

what you mean no pressure on the pedal?

If you've got no leaks anywhere downstream of the master cylinder, and still no pedal pressure, then the only culprit is the master cylinder. brake booster will actually cause the pedal to get hard if it fails- just like pumping the brakes with the engine off.

(have you tried that? pump the brakes with the engine off and see if the pedal builds pressure then.)

 

yea when i pump with the engine off there is a lot of pressure, but when i pu tthe car into drive the pedal goes all the way down before there is any pressure or the car stops? also when i drive if i pump the brake a few times before i apply more pressure the brakes work better? like the master cylinder is not building enough pressure to stop the car???????

 

that's weird, but it sounds like the vacuum booster may be the culprit. if you're getting pressure in the master cylinder before you start the car, then it sounds as if it's working.

if the pedal drops to the floor afterwards, it sounds like the brake booster may be bad.

 

what am i looking at as far as repair/part cost on a new brake booster? this whole problem started after i let my car sit for the summer, when i got home no brakes?????????

 

if you go used, you're looking at probably $100 in parts or so. that's for a master cylinder and brake booster.

At this point, I'd highly suggest taking it to a brake shop though.
at least give someone local to you a call and get the advice of a "pro" before spending money on parts you may not need.

ummm.. since you've got drums in the back.. were the wheel cylinders leaking back there? it's very common on the drum brakes to leak fluid back there- especially then the car goes a long time between drives. try pulling the drums off and take a looksee at them again. if you see any fluid there, then they need to be replaced.

 

No, if the pedal drops to the floor at all it's due to either a leak in the brake circuit or bad seals in the master cylinder as discussed previously. It may seem odd that pedal firms up with engine off - leading one to suspect brake booster. Remember it's the vacuum in the booster that assists with forcing the brake fluid out of the master cylinder down the brake lines. With the engine off, you're having to do all the work & that's not easy. What gives the game away is "the pedal dropped to the floor after the engine started".
I'm gonna assume you checked the rear wheel cylinders & found they weren't leaking, so still suspect master cylinder needs replace / rebuild.
Yes, you will have to bleed the brakes again after you replace master cylinder - read previous thread as I've posted extensive notes on the how & why.
Yes, take car to brake shop to get a second opinion - doesn't cost & helps ease your mind that you're on the right track.
Interested to hear how this all turns out - good luck.

 

thanks again for all your help guys, i have togo the dealed today to get some stuff, while im there ill have them check it out.

 

check your vacuum lines on your master cylinder and brake booster first.

 

ok and how do i go about checking the vaccum line? or the booster?

 

when i did my brake service i had absolutely no brake pressure till i bleed the brakes the way that it was described in the service manual. Does your car have ABS or not?

 

oh and did you bench bleed the master cylinder?

 

maxine89 hasn't even replaced master cylinder yet! While it's preferable to bleed master cylinder before hooking it up to the system, it's not necessary - just takes longer to bleed whole system afterwards.

Master cylinder doesn't have a vacuum line - only booster. Pedal dropped to the floor after engine started = booster vacuum working.
Aye Carumba! The whole brake booster thing is a red herring

 

ok master cylinder has been replaced! brand new and there still is no pressure? the lines have been bleed all the way around and still nothing? also just noticed the right hand rear drum has a small leak????? im replacing the brake cylinder now. could that be the prob? no abs by the way

 

I had almost same problem two weeks ago.
changed both side wheel cylinders, problem solved.
Mine are rusted inside and frozen, one is leaking.
You must have got a leaking in the wheel cylinders.

 

http://www.cybrrpartspro.com/Chilton...961CH09_7.HTML

Check the brake booster now.

 

ok so i just went out and took off both drums to find that there is a leak on my drivers side comming form the wheel cylinder. now i ran out off daylight so i guess i gota to continue tomorrow unless isabell decides to ruin my plans.

 

Woohoo! found the problem!
be sure to clean up the pads and drum with brake cleaner before you put it all back together.

wheel cylinders are usually about $35 each from parts stores. not too bad. I suggest replacing both since you're already doing it.
Hardest part is removing the shoes off the drums in back.

 

$35 ea for a wheel cylinder? My customers complain when they're over $15.
Time to find new customers

 

I thought Matt said "check the wheel cylinders" like the second post....and maxine89 said "I went ahead and changed the front and rear brakes" in the first post..AND bled them...how do you do all that and not see a leaking wheel cylinder??

Don't get me wrong, I miss stuff too, but sometimes I don't think people LISTEN to good advice.

In other words, getting as far as the master cylinder apparently should not have been necessary. Sorry, just my .02

 

You sell many Maxima parts?
It's one thing to replace parts on a Chevy or Honda. they're everywhere and cheap. Try finding Maxima parts for cheap. just don't happen often.

 

wheel cylinders for 89 maxima less than $20 ea in coniseal (brand I stock Good quality too)
Yes I do sell a fair amount af maxima parts. lots of G3's around my area.

 

Yeah, I remember suggesting to maxine89 to check the rear wheel cylinders - amongst other things - in her first thread way back when, as this is a common problem - guess she must have missed it and had to spend $??? on master cylinder (probably not a bad idea anyways...).
The Max should use same wheel cylinder as most mid-size 4-pot Nissan's cars & trucks. I pay NZ$35 per wheel cylinder - about US$20. Usually Tokico with 7/8th fittings. Very standard & easy to come by - at least in NZ anyways.

 

durn good prices.. they're $35 from the parts stores around Tulsa, as well as the dealer price. That was for Tokico or wagner cylinders. ahh well. I have discs now anyway.

 

$17.50 ea in coniseal

 

ok so maybe i did miss the post way back when, my bad... well the master cylinder had a small leak anyways so that needed to be replaced. as far as noticing the rear wheel cylinder, i was doing the front brakes while a friend was doing th back so i guess he didnt think anything of it??? well its raining today so i cant go out and fix the cylinder, but thanx for all the postsit really helped alot.

ps maxine89 is not a girl, im a guy, i just knicknamed my car "maxine" just to clear that up

 

Yeah, I remember you saying someone else had checked the rears - and you've had so many posts advising this & that easy to miss stuff. Figured maxine89 was name of car & didin't want to assume name of owner - although maxine appropriate name for girl max owner My roomie named my car Enzo 'cause she's a big Ferrari F1 fan & the car's a dark red color.
Hope everything all works out now.

 

thanx very much nismobaron, youve been a lot of help! well at least now i know everything i need to know about brakes! lol. well now lets just hope that that wheel cylinder is the problem, and the final problem!