SayNoToPistons

iTrader: (8)

Well since I got my new Racing Brake ET500 pads, I decided to swap them in with a friend. Everything went as planned until we hit the left rear caliper. The piston refused to contract into the cylinder. After much trouble, taking the caliper off the lines, and took apart the caliper itself, we discovered that the threaded sleeve inside was ruined. Left my car 2 hours away at my friends, he drove me home and back with his car.

He wakes me up the next morning and says that he couldn't find any places that sells just the pistons or sleeves alone and a new caliper is $304 at Mazda. He took a tap to it and tapped out about 1/3 Inch worth of thread at the end and some how got the piston to compress and extend enough for the new pads to go in as a temporary fix for a few thousand miles perhaps.

OK, so while that is temporarily fixed, we bled the brakes. First we bled them by pumping the pedal, flooring it, bleed, and repeat a few times for all four. We refilled the reservoir with DOT3 also. Well, that didn't work since the pedal was mushy.

So we followed a few DIY on the forum. Bleeding with with the master cylinder first with one stomp on the pedal and flooring it, and repeating on all four wheels, then back to bleed the MC again finally.

Pedal was still very mushy but seemed drivable. Took it for a spin and bedded the pads in. Even hit ABS a few times. The pedal was still very mushy and had much more travel than before the brake job.

Left it as is and we went to grab something to eat.

On the way home during my two hour drive, the pedal had no feel, very mushy, and the travel was even longer than before. I have to press the pedal nearly 3/4 of the way down to get any real braking. I tried the ebrake, even though it was stiffer than before, not much real braking force was produced. It also seems like at least one caliper is sticking because the car does not roll after coming to a stop on slight inclines/declines. I also got squeaking from the passenger side slowing to a stop at almost all times.

Finally limped it home through traffic. Checked for leaks under the hood and on all four calipers. I couldn't find any other than the areas that may seem like it was soaked by fluids during bleeding .

So I'm looking for suggestions now. I will be replacing the left rear caliper with a used unit. What is the solution to my horrible brake pedal travel (or the lack of "brakes") and squeaking?

Thanks in advance. Sorry for the long read.

TeamRX8

iTrader: (25)

It's probably that caliper

Dare I say it ..... just say no to brake pistons, lol.

Mazurfer

No doubt the caliper needs replacing, but doesn't it seem like there is still air in the system somewhere?

SayNoToPistons

iTrader: (8)

Perhaps. The caliper seems solid unless I wear the NEW pads down to or past minimum spec. My friend was in charge of bleeding while I was stomping the pedal. He said he made sure that the (problematic) left rear caliper bled fluid when he closed it.

Mazurfer

Forgetting the caliper fiasco for a second. How the brakes and pedal are acting is just the same as my daughters 3 until we bled them again and got all the air out. ??????????

SayNoToPistons

iTrader: (8)

I'm going to assume that there is air in the system and we just need to keep bleeding. THe thing that is throwing us off is the fluid coming out during bleeding instead of air. Shouldn't the lines be air free when fluid comes out instead of air?

Brettus

iTrader: (2)

Priobably the dodgy caliper not indexing properly and falling away from the disc .

But just in case it's a bleeding issue :

you should pump the pedal a few times before you loosen the bleed screw and pump out some fluid . Then shut the bleed screw off before the pedal is released .
Hope you are using a tight fitting bleed hose too ?

SayNoToPistons

iTrader: (8)

We used cups to catch the fluid. No hose was used

TeamRX8

iTrader: (25)

Say wha ......

SayNoToPistons

iTrader: (8)

Yes. Do tell.

JantzenRX-8

iTrader: (9)

Every time i've experienced this it's been a bleeding issue. Just relieve some pressure and it should retract. If that doesn't work it might be something more major like others are saying.

Brettus

iTrader: (2)

get a proper hose and bleed it again !

ken-x8

Then you would not have seen whether you were getting just fluid, or if air was mixed in. You need to use a piece of clear tubing so you can see what's coming out. In the old days, before clear plastic tubing, you'd catch the fluid in a clear glass bottle or jar, with the end of the hose immersed in the fluid so you could look for bubbles.

Your use of the word "stomp" does not give me a warm fuzzy feeling. There should not be any stomping involved. The process is:

1. Open the bleeder valve
2. Push pedal to the floor, taking a couple of seconds to do it. Observe fluid in tube for air bubbles and cleanliness
3. Tighten bleeder valve
4. Let pedal come up, taking a couple of seconds.

Repeat til done. Stop every now and then to make sure the reservoir still has fluid in it. If you let the reservoir get empty and suck air into the master cylinder, you might need to bench bleed it.

Rather than get a used caliper to replace the bad one, see if you can get a rebuilt. It will be used, but it will have new parts in it.

Ken

cjkim

if all else fails, gravity bleed.

takes longer, but there's no second guessing about air.

Razz1

It's the Bleeding and... Junk yard is your friend for a caliper.

SayNoToPistons

iTrader: (8)

Thank you all for the advices. Where can I look for a rebuilt caliper? I have searched high and low for caliper parts (piston) and rebuilt calipers on google and havent had much luck yet. I have found used calipers on the forum and on ebay though.

nycgps

iTrader: (1)

Just find the cheapest used Caliper that you can buy. perhaps go shop at juke yards.

Im 100% positive that they will have the rear calipers for sale like hmm maybe 50 bux each.

how you even broke it in the first place O_O

cuz those parts are pretty strong. hell even my 19 yr old PoS FC has pretty nice looking pistons

alnielsen

iTrader: (4)

Call Mazmart for a used one.

RotaryResurrection

iTrader: (3)

Sounds like there is air trapped in the ABS unit. Some of the older ABS units had bleed valves right on them. In some modern vehicles air gets trapped in the ABS unit and the only way to properly bleed it is to have the dealership command the ABS unit to activate each internal solenoid in sequence using a specialized computer (tech2 for GM vehicles, etc.), and then re-bleed each wheel circuit once that trapped air has been forced out and into the lines.

There is no accurate way to bleed the ABS units otherwise. Some people theorize that going to a gravel lot and activating the ABS several times can help, but you can not be sure that all wheel circuits and solenoids have been triggered, so you cannot be sure all air is out. Also, even if you did manage to activate the necessary ABS circuits, what is to say that the air bubble will move out through the line and into the caliper, and not simply return right back into the ABS unit?

This only happens when a caliper is disconnected and a large volume of fluid exits (thus air enters) one or more brake lines, or if the brake master cylinder reservoir goes empty for some reason.

SARRAS

Ouch! get some bleed hoses and do bleed the brakes AGAIN - this time with the engine running - you have to run the engine on ABS equipped cars to get a decent bleed

SARRAS

Ouch! get some bleed hoses and do bleed the brakes AGAIN - this time with the engine running - you have to run the engine on ABS equipped cars to get a decent bleed

Mazurfer

Yes sir, that's how I've always done it.......the old school way with one modification, and that is I have a heavy nut on the end of the bleed hose that goes into the glass jar to keep it down and totally immersed in fluid. My hose isn't clear, but using the glass jar, you can easily tell if you have bubbles of air.

Spin9k

Try using a search engine, like Google with "rx-8 rebuilt caliper". This came up immediately http://www.partstrain.com/store/inde...rake%20Caliper

Take your choice of several...

SayNoToPistons

iTrader: (8)

When we took off the caliper to check why it isn't going in, the piston was already crooked. Perhaps it over extended and the pressure of the brakes caused the hardened steel stud in the cylinder to mangle the threads in the sleeve in the piston.

The rear caliper was taken off to inspect the damage of the internals. I'm going to bleed the brakes properly again and see if that helps. This time with a clear hose.

Doesn't exactly say rebuilt calipers there. Either way, I can't go wrong if I can find a used caliper for 50.

ken-x8

The old ways are the good ways.

I was taught by a high school shop teacher about 50 years ago. I initially wondered why it was important to start with some fluid in the jar, since I could see the fluid in the plastic hose. Then I realized that when he learned to bleed brakes there was no clear plastic hose. Nut on the end of the hose is a great idea.

I trained my wife, who is afraid of mechanical things, to be the pedal pumper. Gives a nice moment of teamwork. Otherwise when I work on the cars she hides inside the house and prays that nothing will blow up.

Ken