Brake fluid flush

[Tsel]

Hello all,

My '97 toyota corolla is having some front brake issues, locking up but after an hour or so of not moving the car they are released again and car is drive able again.
Anyone I speak to is not sure what the issue could be.
Already replaced pads and greased the pins.
It was suggested to do cheapest thing first. which seems to be a brake fluid flush, but I have no idea how to do that. I was reading about it and seems I remove all fluid from the master brake cylinder, then fill with new fluid, then bleed each tire until new brake fluid starts coming out.
Thing is I am not sure what tire, or if it matters, to bleed first and also how do I do it if I want to clean the system not just flush the fluid.

Any advice, guide, post, or any help would be very appreciated.

Thanks

[mvftw]

Maybe your brake hoses are breaking down and not releasing the pressure keeping the caliper from returning...

[godanigo]

I would check your brake booster. it's possible gasoline vapor from the engine is heating up when the car heats up, and building up to much pressure in the booster. it's unlikely, but worth checking.

[ganda1f]

Originally Posted by godanigo

I would check your brake booster. it's possible gasoline vapor from the engine is heating up when the car heats up, and building up to much pressure in the booster. it's unlikely, but worth checking.

Brake booster does not *build* any pressure. It is evacuated by the vacuum in the intake.
Do all wheels lock up or just one?
All wheels locking up would suggest a problem in the master cylinder.
If a single wheel locks up, the piston in its caliper could be sticking. Possibly due to corrosion on the piston surface.

[speedy25]

The problem is the compensation port is blocked. What that means is you now have a closed system with no means to compensate to brake fluid expansion when the brakes get hot.

You should have done that flush sooner!

Proper practice is rebuild the master cylinder and remove whatever gunk is blocking the port. Quick and easy but NOT RECOMMENDED is to run a small wire into the hole to open it up. Its not a good idea since whatever crud that was in the hole may compromise your brake system.

The other possible but not as common problem is deterioration or rubber brake hose. Some have had them turn into one way valves and not let fluid return. Typically these dont release when cold though.

-SP

[Shuttlepod One]

If you plan on doing this yourself, a great help would be having an experienced friend over to teach you. This could turn into a long learning experience for you.

If your old master cyl is clogged, which you are only going to be able to determine by removing it, you can either rebuild it, or buy a remaned one. cost is about $52 for a reman from O'Reilly, NAPA, etc.

If you don't already have the Hayne's repair manual for the car, get one. Verify if you have ABS or not, it will matter. A reman or rebuilt brake cyl will need to be 'bench bled' to ensure all the air is out. You can do this with it installed in the car but it's much easier to set it up on a work bench, clamped into a vice.

After that you need to bleed each wheel. Farthest from Master to closest. Rear right, rear left, front right, front left.

Tools and stuff you might need:

• 10mm flare nut wrench (master cyl bleeders)
• 10mm box end wrench
• 8mm or 5/16 (i think) closed end wrench for the bleeders at each corner
• clear tubing and a one man brake bleeder
• long bar to hold down the brake pedal (i used a length of plastic vacuum cleaner tubing, moved the seat forward and depressed the brake with it 3/4)
• lots of brake fluid (1 or 2 quarts)
• new or rebuilt master cyl
• 2 speed bleeders for the master (possibly 7/16ths thread, mine was on my 95)

The technique on how to bleed the system starts with the master if it's run dry. Can be done on a bench or in the car.

• install the 2 speed bleeders
• run hose from each into the master fill area
• secure hoses to master so they don't spray fluid all over
• get in car, pump brake until no more bubble come out of lines
• don't go nutty, long even pumps with a pause holding it down in between
• if on a bench you use a screw driver or a rod to push the cyl and force air out (dont push to fast or you'll have a fluid volcano)
• reinstall the 2 lines back onto master (a little fluid will run out, don't worry)
• begin corner bleeding or install master back on car if you were benched

Now is a good time to replace pads, shoes, and have rotors/drums machined and checked for run out. Last thing you want is the shaky shakes after all this work.

Bleeding each corner:

• Begin at right rear corner, further from the master.
• Use closed end of wrench, slip over the bleeder
• Push clear hose over bleeder
• Set bottle to catch fluid somewhere (preferably higher than the bleeder)
• make sure there is some fluid in bottom of container (you don't want the hose sucking air back into the line)
• install brake hold down and push to 3/4
• go back and crack the bleeder open
• wait for the bubbles to stop
• close bleeder
• rinse and repeat till no more air is leaving the line

• left rear, rinse and repeat per above
• front right, rinse and repeat per above
• front left, rinse and repeat per above

Each time you do this, the pedal will get firmer and firmer. Eventually your goal is to have a rock hard brake pedal after a few pumps. You do all of this with the car OFF by the way.

All said and done you will learn a lot and possibly spend just as much as if you took it somewhere. It all depends how much you screw up and how much brake fluid you go through. Shops tend to have vacuum bleeders which make the job quick and painless. You might end up paying $80 for a brake flush and fill though.

It's entirely possibly I've forgotten some things but the internet is a vast wasteland of YouTube videos and half written how-to's for you to sort through. Also keep in mind this is for a vehicle without ABS, you might have more steps.

Good luck.

[badquenga]

Bleeding brakes is cake. Just watch youtube, it's basically the same thing on all cars. Wait a month and I'll have my youtube video up .

[speedy25]

BE VERY CAREFUL about reman master cylinders!

DONT BUY AUTOZONE! It WILL leak.

Dont forget to "bench bleed" the MC before installation.

-SP

[Tsel]

Status update.

I know it has been a few days but I like to take things slow, mostly when doing something new.

First of all, thanks for the help.

So I decided to do a rebuild using a caliper kit from autozone on the front right caliper, which is the one locking up. After doing that I started with the entire system flush, for the most part went fine. I found it more time consuming than difficult.
The master cylinder in place I started bleeding the tires, back right, back left, front right, then finally the last part of the job, front left tire, taking bleeder screw out it snaps in half. The whole easy part was totally busted on that one last little screw. Tried the easy out methode, heat it up then cool it. Then easy out breaks too. Poor half screw is now fubar. I don't think I messed anything up on the thread. So now I am waiting for a friend to see if we can solder a nut into it and try removing it that way. If not then I will have to fork out the money for a new caliper which I thought I had saved.

Anyways, thank you guys, the information was very helpful to me who never done this before.
Tsel

[Shuttlepod One]

If there is anything to grip, you could try grabbing it with vice grips and twisting the wreck out. Then install a new bleeder screw. The calipers are so easy to rebuild you might as well redo that one while you are at it.

Sucks when brake jobs go into land.

Don't forget the slide pins and boots for it. If they are worn, get new. Grease em up and go.

[sequoiasoon]

definitely check/change the boots for the slide pins. I had one rip but on "normal" brake inspection all looked fine. One ripped and the slide rusted and the inboard pad wore down at an angle (but looked great from the top). I've had the hoses break down as described. Started great every day after 4-5 stops right front would start to drag heating pads causing brake fade. Next stop car would pull left real hard almost changing lanes. Not good under emergency braking. Real easy to change and not real expensive while your there.

I use a Motive pressure bleeder and ATE Blue (and alternate with typ 200 gold) fluid when I do it. Same fluid just tinted lets you know when full line is bled out as it changes to new color.

[badquenga]

Originally Posted by sequoiasoon

I use a Motive pressure bleeder and ATE Blue (and alternate with typ 200 gold) fluid when I do it. Same fluid just tinted lets you know when full line is bled out as it changes to new color.

Ditto on the Motive pressure bleeder! BuyBrakes.com has a youtube video for the universal adapter and I think it's even on a Corolla. I bled brakes via 2 man process too many times and it takes too long. Bought this thing and did my M3 in 20 minutes...which includes jacking up and taking off each wheel.

[speedy25]

My tool of choice is a mityvac vacuum pump with the fluid reservoir. Most of the time I can do it without removing the wheels. Only disadvantage from the Motive piece is you have to check the reservoir and make sure it doesnt go empty. I'll also add that the FIRST step is to suck out the old fluid from the master cylinder, remove and clean the reservoir. Mine was nasty with all kinds of ugly deposits!

-SP