sinking brake pedal

[k624ash]

i just removed the abs on my car and since then the pedal has slowly been sinking, somtimes worse than others. at first i found a few loose lines and tightened them down. but now all the lines are very tight and i cant find any leaking fluid. i bled the brakes a couple times, but i havent bled them since i tightened down all the lines. Do you think another bleeding will fix it? or could it be my master cylinder?
i know a bad master cylinder can be the cause of the sinking pedal, but mine worked fine before so i dont see why it would be bad now, unless switcing the lines out somehow ruined my master.

id like to hear peoples opinions. im going to bleed it again in the next couple days, but does it sound like i need a new master cylinder? also if im going to replace the master, i mine as well replace both that and the booster with an rs one right? i think the si one would work also

 

[weksos]

I would try bleeding it again to make sure. It does sound like a bad master cylinder though.

 

[jdmvtecboi]

I would try bleeding it again to make sure. It does sound like a bad master cylinder though.

X2

 

[integra4life29]

you got air in your brake lines....bleed them again

 

[k624ash]

i bled it today, it still sinks, but less than eariler. but like i said in the original post sometimes its worse than others so it might be bad tommorow.

any reason why the master would go bad on me all of a sudden like that? could removing the abs or bleeding the system have caused it to go bad?

ive noticed that the idle and the brakes are connected, like if i push the brakes hard or let off quick the idle will change. also it seems when the brakes are sinking quick the car shudders a tiny bit. could it be some sort of vaccum problem?

also is there anything to check other than the master cylinder?

 

[nexgenintegra]

yup like everyone is saying sounds like a bad master. happened to my boy's 4 door had the same exact problem swapped it out worked like a charm

 

[k624ash]

also where should i go to buy a new master? id like to get a dealer on but they are like 230, any other cheaper ones that are good quality? i doubt buying a used one is a good idea

 

[k624ash]

and since i removed abs should i get a non abs brake master and booster? or is that not worth it?

 

[GSratedR]

on my old del sol i had the same prob. i just bought a new MC and it was like 68bucks. i got mine at pep boys and it was a rebuilt one but it worked perfect.

 

[k624ash]

on my old del sol i had the same prob. i just bought a new MC and it was like 68bucks. i got mine at pep boys and it was a rebuilt one but it worked perfect.

how long ago was that? is it still working good? cause i dont want to spend 200 bucks on an oem replacment but i also dont want a crappy one

 

[GSratedR]

how long ago was that? is it still working good? cause i dont want to spend 200 bucks on an oem replacment but i also dont want a crappy one

i sold it to get my gsr like 6 months ago but i had put another 12000 miles on it after the install and it was working just fine when i sold it off. but yeah i got mine at pep boys and they gave me a rebuilt unit and it was all gravy after that. i suppose you could get it at any of your fine auto retailors in your community.

 

[k624ash]

i sold it to get my gsr like 6 months ago but i had put another 12000 miles on it after the install and it was working just fine when i sold it off. but yeah i got mine at pep boys and they gave me a rebuilt unit and it was all gravy after that. i suppose you could get it at any of your fine auto retailors in your community.

yea its just that not too long ago pep boys sold me an axle with a torn cv boot, but i didnt realize until after i put it on, what a pain in the ass. They replaced it for free, but i had to go through the work of changing it twice. plus it got tons of axle grease everywhere.

 

[GSratedR]

yea its just that not too long ago pep boys sold me an axle with a torn cv boot, but i didnt realize until after i put it on, what a pain in the ass. They replaced it for free, but i had to go through the work of changing it twice. plus it got tons of axle grease everywhere.

thats a tough one i would just go to a different store and buy it. the change on the MC is pretty easy, but make sure you have the right line wrench cause i tried to do it without it and ended up stripping the bolt and having to cut and bend my own new brakeline. that was a bitch. so yeah i would just get it from another strore. oh and you might ave to reuse your old resivuoar. i cant spell.

 

[nautica_t]

to answer your question in regards to the brake pedal feel when you push it hard and hte revs goes up its due to brake booster works on vacuum. so when you brake hard or pump it, the engine is under load to create a vacuum this is why you hear the car/feel the car do that. its perfectly normal.


as for a MC malfuction, they can just fail, there's no way to really test a MC for failure, if it wants to go it'll go, espically if it gets too much air in it, the rubber o-ring seals can rip. i mean anything is posible right, or just over time it gets warn, but maybe it was going in the first place and by removal of the abs unit you got my air in the MC and provoked it to fail sooner.

but like i said it my not even be a factor.

bleed the line like 4 times through. remember with engine off and shit, but i'm sure you know how to do it.
futhest away from the MC first. so right rear the left rear than passenger front and than drivers' front.

upon doing so, stay at one location for a couple of times, until you see absolutely no air come out, its a straight stream of fluid. you may need to use one bottle of brake fluid. and be sure to constantly keep it topped up and have the lid closed so it has pressure.


good luck. and tell us what happens.
if you do have to get a new MC. get flare wrenches, otherwise you'll strip those lines and its not going to be a fun thing to do to get it replaced. and don't forget to bleed the lines as well. there should be fittings inside the kit to prep the MC>

once again good luck with everythign and fill us in.

 

[k624ash]

yea i already bled the crap out of it, i went through a little more than one of the bigger bottles of preston fluid. it hasnt been a problem recently but i think thats just cause its cold out. i have the proper wrench and will at some point get a new master cylinder. maybe in the spring, i dont feel like doing the work while its cold out, unless it becomes more of a problem.