I was on my way home when I was coming to a stop and the break pedal just went to the floor and lost pressure. It would only stop after hitting the floor with the pedal and only the rear wheels. Well, I replaced the master cylinder after inspecting it and noticing some "pieces" in the reservoir. The problem is that after replacing it, it still has no brakes. The pads are all good, there is very little pressure going to the bleeding lines and it won't brake for crap. I tried looking around here but most of the threads are dead end with the same problem but they just stopped posting. The booster is fine and we bled the lines and the MC it self, for 2 hours with about 3 bottles of fluid to make sure we got all the air out. I've heard of the LSVP? or something like that? Can anyone please help before I call salvation army and make a donation?



Thanks.

 

anyone with any sense of care to respond?

 

did you find pieces in the MC reservoir after you replaced and bench-bled the MC? If so, you obviously have a bad MC. replace it, bench bleed it, and bleed all 4 wheels again.

 

The pieces were found before replacement, that's why we replaced. We bled all including the LSPV and still no brakes. I think I'm going to sell it to a local dealer for 1K or less. I'm sick and tired of this pos.

 

Same thing happened to me a few weeks ago. Mine got better after the master cylinder was replaced. Pump up the brakes and hold 'em down as hard as you can, does the system lose pressure? If it does, do it a couple more times and see if there's any fluid loss, and if there is look underneath and see if you can see where it's coming from.

 

No fluid loss. This thing has me puzzled like nothing ever.

 

Was the master cylinder replaced with a new/rebuilt one? Just to be sure the brakes were rear drum/front rotor, right? I know I had a problem on my Mazda where the rear shoes would wear to the point the piston would pop out the end of the wheel cylinder...not too sure what to say, maybe some debris stuck in the lines keeping it from bleeding properly?

 

Yep, a NEW master from autozone. There is absolutely no brakes at all, only the e brake, and that's not even stopping the car. Don't know. Gonna have to tow to a shop and if it's too much, I'll just leave it there for 500 bucks. It sucks cause this thing is in great shape, only has 100K on her and everything works, but I'm not dropping more money than what I paid for her on repairs...

 

I've had the same luck with all types of aftermarket MC's,new or (used)reman.If it were mine I would get a new Toyota(Aisin) MC and go from there.Make sure the rears are adjusted up.If the rears are out of adj the E brake will come way out when you pull it.Sometimes they are just hard to bleed but You must have a good new MC to start with.Bleed the farthest wheel first from the MC and so on and then bleed the LSVP.I took mine out due to a lift but that another story.I'm not being a smart ass but do you know how to bleed brakes?I'll tell you how I do it anyway and it works perfectly but it takes two people.One man operates the pedal.The other man opens the valve.Make sure MC is full always if it runs out then you have to start over.Open the bleeder,put your finger over the hole with a little pressure.Pedal pumper starts pumping continuosly,you'll feel it pushing and pulling on your finger.You need to get in rythm with the pumper.You may need to let your finger off the bleeder on the down stroke and plug the bleeder on the up stroke.If all else fails you can gravity bleed it.Fill the MC open F or R bleeder and go to lunch.Takes awhile but this works too.

 

i had to rebuilt master cylinders in a row taht were crap on my 93 4runner i ended up having to go oem and then it solved the problem.. expensive but worth it...

 

Could that be the cause? I mean, the brakes went out when I was coming to a stop. My friend replaced the MC and bled the whole system. There is pressure going to all the lines, but very low pressure and there is no brakes at all.

 

Ok. Tried all that again, over and over until the last single bubble came out. Still no brakes AT ALL! that's what's bugging me, at least I should have some sort of stopping or gripping right? If it's not the MC, what could it be? There is not a single drop of fluid anywhere under the car!

 

Well, there's definitely something wrong with the pressure, must be the MC. I tried bleeding again and there's more air than ever and no pressure after a few pumps of bubbles and air. I will tow to a shop tomorrow. This is certainly my first brake issue that really ate me alive.

 

Its got to be the MC. Take it back for a refund.

 

yeah maybe a bad seal in the MC or a way for air to enter it. If after bleeding it repeatedly you're still getting air out of the end, then that means more air is entering the line somehow, the MC is really the only answer.

 

Nothing yet. Power bled the system and nothing seems to work. Got all the air out, pedal still mushy and super soft with no brakes at all.