Dan_s_young

iTrader: (1)

Hey guys.

I just finsihed the suspension on my car a little while ago and in order to do it I needed to take the front calipers off. Now in the process of this I hung the caliper up as to not damage the hose.

Anyways, the car is now back together without the front anti rattle springs. I pushed the caliper pistons back with a C-clamp and pumped the brakes up before driving of course. The brakes seemed to be engaging very late, as in with the pedal 2 inches off the floor. At first I thought the system could just need to be bled but today I bled the brakes and the pedal is still engaging late.

So my question is: Is the problem of late engaging brakes possibiliy caused by not using the anti-rattle springs? The lines are bled but the problem persists and I have no idea as to what else my problem could be...

Thanks

evil_motors

iTrader: (3)

maybe you damaged the piston .. or maybe you somehow messed up the master cylinder.. thats the only thing i can think of.. do you have pleanty of fluid and did you bleed them in the correct order?

JIMMY54

iTrader: (2)

I have the same problem pretty much.....4 master cylinders later, and still same problem....However im not sure about you, but when it starts to engage...it REALLY engages, as in,,,very sensitve....Will lock up easy.... I thought it had somthing to do with the fact that i installed a Line lock on the front lines, but i guess not.... Check your booster maybe? Mine seems ok, but who knows, maybe thats your problem?

Dan_s_young

iTrader: (1)

There is no way the master cylinder or Caliper is damaged. I was very careful to tie the caliper out of the way and I did not touch the master cylinder.

The only thing I can think of is that the anti-rattle spring would somehow help to engage the front brakes faster? I dunno im confused....

And the problem isn't my booster either, I still have perfect assist...

Maguire

iTrader: (1)

the cailper could just be starting to seize. and when you pushed them back in, now its getting friction on the corroded part. I was having the same problem. the either didnt work. or they poped when i pushed on it real hard. i would recommend investing in some new calipers. you can get a pair from rockauto.com for $60. thats where i bought mine, they even came with new slide pins. hope thats helpful info.

LokiRx7.1

iTrader: (1)

the anti rattle springs have nothing to do with brake engagement, used to own an sa with this problem and it had sat forever. the pistons were frozen inside the calipers. moisture had worked its way around the seal on the brake piston. I also had to buy new calipers that solved my problem

t_g_farrell

iTrader: (1)

I agree with the piston catching or seizing. When you pushed it all the way in it probably came in contact with some old scale that was on the rear of the caliper bore and now its not sliding smoothly. One suggestion is you can just rebuild the calipers yourself if they aren't too far gone. You'll need a caliper rebuild kit and a small hone that will fit inside the piston bore. I'm talking about the little hones that look like smaller versions of engine cylinder hones with the three stones attached to flexible wire that you can use in a drill. Its a lot cheaper than getting new calipers and really doesn't take much time. While your at it check you might want to check the rear brake cylinders ( if you have drums in the back ) and replace them as well.

Dan_s_young

iTrader: (1)

hmmm that sucks if the pistons are seized... Why can't they invent rotary brakes? lol...

Ill take another look at it when I have time by having someone apply the brakes and I watch what those suckers are doing. It would be nice to get some new calipers in there though...

Kentetsu

Naw, you guys are all way off track. If it was a siezed piston, then the pedal would not be going almost all the way to the floor before meeting any resistance. I think you screwed up when doing the bleeding procedure, which seems to happen to a lot of people. Get some of those fancy bleeder nipples from Autozone and try it again.

If you had rear drum brakes, I might consider that those were out of adjustment and causing the slack. But since you have a GSL that's out of the question. Its your bleeding bleeding that causing the issue here. And yes, that is my final answer....

Tanjo

You bled in the right sequence, right?

Dan_s_young

iTrader: (1)

well I bled by passenger side rear, passenger side front, drivers side rear, drivers side front. Which I know isn't quite right, (supposed to do farthest to closest) But isn't bleeding in sequence only to prevent new fluid contaimination with the old stuff?

I didn't use speed bleeders, I did it the old fashioned way. With an assistant, hold, release, hold, release.. As I opened and closed the bleeder. I bled all the old fluid out.

But like I said the problem with when the brake pedal applied the brakes was just as bad as it was before... Will the speed bleeders really make a difference? And why, its just doing the same thing is it not?

Kentetsu

Well, doing it the old fashioned way you are more likely to make a mistake and let air into the system. Also, make sure that you bleed in the proper order. The only reason that you could have a soft pedal now is either because of air in the system, or fluid seeping past the pressure seals in the master cyclinder (assuming that you don't have fluid shooting out of your calipers or somewhere else).

Dan_s_young

iTrader: (1)

Thanks for the quick reply. I think the next thing im going to do when I have time is try and take a look at what the front calipers are actually doing...

I agree with you though that it sounds like a hydraulic problem... I just thought that I could cross that off my list now that I bled my brakes...

Also I think its weird that the problem could be the master cylinder if it hasn't even been touched. I realize that its possible but its more likely the problem is elsewhere... I'll take a look and see what I can see (when I have time, im really busy)

Kentetsu

Well, the thing about master cylinders is that they can work forever as long as nothing changes. But when you bleed brakes using any method that involves pushing the pedal, you are asking the MC to do something new. When the brakes are in use, the main plunger in the MC moves along the same area of the cylinder all of the time. But when bleeding brakes, you push the pedal all the way to the floor, so the plunger is now running into parts of the cylinder that it only sees once in a blue moon. Now, the part of the cylinder that is always used has worn in along with the seal for twenty years, and they're getting along pretty good with each other due to their long term relationship. But when it runs into the unused portions, they might not match up to the seal as well or there might be a burr, ridge, etc. Anyway, you always stand a chance of messing up the seal by asking it to run along the unused areas of the cylinder. Hopefully your issue is simply air in the lines, and not a bad seal in the MC. Good luck.

84stock

iTrader: (5)

I agree, air in the system somewhere. Are your rears adjusted up right, could impact as well.

Dan_s_young

iTrader: (1)

The rear calipers were never taken off the pads so they should be fine. I just don't understand the concept of how air could get in the system.... I guess ill take a look at it in a little while here...

t_g_farrell

iTrader: (1)

Theres two things that I can rememebr hitting that are specific to rx7 brkae bleeding. One is that the brake bias valve is not centered and only the one end of the brake system engages ( front or rear ). Doesn't sound like you problem, but its something to check. The second is that if the master cylinder has air in it, you need to bleed the master. Theres a bleed screw on the master. I ran into both of these when I emptied the entire hydraulic system while doing some major suspension/brake work earlier this year. I never drove the car when this happened tho so I'm not sure what the symptoms would be except I would get what felt like a hard enough pedal but would see no pressure to the rears when I was bleeding ( that was caused by the brake bias valve ). Then I bled the system and the pedal was still not right, kind of soft. I then realized I didn't bleed the master after I rebuilt it. Once I did everything was fine.