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Changing hub bearing now brakes are shot

Combatcm

NAXJA Forum User
Location
NJ
I was changing my hub and took the caliper off then pressed the brakes by accident and the pad came out of the piston and there is brake fluid everywhere. I've never done a brake job before and this really sucks. I'm assuming im gonna need new pads all around cause i need them anyway. And im gonna need to clean them up good too. I dont want to touch it until i know what to do.

Any advice welcome.
 
you can purchase a caliper rebuild kit and reseat the piston in the caliper and reassemble everything, but the calipers are fairly cheap. I'd replace the caliper and pads (you need 'em anyway) and bleed everything until it's all new brake fluid.
 
You almost certainly need new pads if fluid contaminated them, and it's probably not a bad idea anyway, since a wobbling wheel bearing can wear the pads on that side prematurely. As for the caliper itself, it may depend on how well you can get the piston back in, and whether you can do this without damage either to the dust seal or the piston seal. If there's brake fluid escaping, you certainly pushed the piston out past the seal, so you will have to push it back. The dust seal is the bellows-like boot that surrounds the visible part of the piston. The piston seal is inside the bore of the caliper. It stands still while the piston moves back and forth, and cannot actually be removed without removing the piston completely.

If I were doing this, I'd try putting the piston back in (just press it in slowly, and as straight as you can. A C-clamp should work well for this, but make sure you don't chip the piston which is made of plastic). Clean it up as thoroughly as possible, so that there is no old fluid showing. If the dust seal is off, leave it off for now. Then, using old pads, reinstall the caliper on the disk and push good and hard on the pedal a few times to operate the brake. If there is no leakage past the piston seal, take the caliper back out and reinstall the dust seal if you took it off, put on the new pads, button the whole thing up, and keep a hard eye on your fluid levels and a nose for fluid leaks for a while until you're sure. If there is even a tiny bit of leakage, get a new or rebuilt caliper. It's probably not a good idea to try to rebuild the caliper yourself.

If you can't trust the piston seal, new or rebuilt calipers shouldn't break the bank, and better safe than sorry.
 
Yeah, i purchased a reman caliper for only $20. I rented a vacuum kit to bleed the brakes, i've never considered doing a brake job yet but now im knee deep in it. I bought new pads too.

I'm still confused after reading a ton of brake bleed pages, im thinking its more complicated than im making it to be.
 
Bleeding with one person is sometimes frustrating but it really is easier than it sounds. Once you do this one you will be set.
 
How much fluid does it take to completely bleed your entire brake "system"?
 
:us:I would think a couple quarts would be sufficent unless you run into some kinda of problem
 
One person bleeding can be a chore, but there are a couple of good ways I've found.

1: For something like a single caliper, a line repair, or a wheel cylinder, where I'm not replacing a master cylinder or giving it a big flush, I have an old gas filled hatch strut, to one end of which I've bolted a little block of wood with a notch to fit under the steering wheel. The strut is long enough so that it will be about half compressed when placed between the wheel and the brake pedal. I pump the pedal up hard, and put the strut in. This produces a single stroke of the brake pedal, usually enough to bleed a wheel cylinder. Just open the bleeder, and close it again when flow almost stops. Repeat as needed. For a full job you'll have to get up and pump, get under and bleed, etc. a number of times, which is a drag, but the job will get done effectively if not handily.

2: For anything more than the occasional bleed, consider getting a hand vacuum pump with a bleeder kit. Once you've gotten used to vacuum bleeding, you'll be spoiled. The only issue here is that a vacuum bleeder can pull out some air past the threads of the bleeder along with the fluid, so the usual "bleed until there are no bubbles" rule doesn't apply. Just bleed until the stream is steady and there's a reasonable amount of fluid in the cup. Usually you'll hear when it's right, because it will stop spitting. Close the bleeder while there's still vacuum present. If you just do each wheel and bleed out a few ounces, you'll have done a good flush too. Just make sure you don't let the level in the master cylinder go down too far and suck air, or you'll have to do it all over again!
 
Certainly not to contradict Matthew, as he repeatedly has proven great mechanical wisdom for all of us to digest (thank you, sir), but I have another method for bleeding brakes that was handed down to me by another great mechanic. Two other brief points first though. One is that any brake part replacement should be done in pairs. I would get another rebuilt caliper for the other side too (unless this was just done recently). The second thing to watch (this was a problem on another thread), is to make sure not to get the calipers on the wrong sides (R to L) because the bleeders will be at the bottom and not let the air out. Anyway - the bleed:

Here's the best way to bleed 'em from an old post.

"I did em that way for MANY years too. Called the kids or the old lady out and told em "pump it up and hold it down", and opened up the bleeder until the pedal went way down. There is a way easier way, but it takes longer. I use it whenever I replace brake cylinders or calipers, but mostly it's just to change the brake fluid, which I do whenever I change shoes or pads. Ideally you change brake fluid at least every other year. If you worked on old cars and saw rusty pistons, you'd know why, but people also say that old brake fluid boils and won't stop you right.

The best way is the GRAVITY method. The only problem is it takes a lot of beer and you don't want to drive right after. (CAUTION: YOU MUST BE 21 TO BLEED YOUR BRAKES THIS WAY!)

1.) Get the car in a position where you can open up the bleeders. I always like to break them loose with a 6 point socket being careful not to break them off. If you can, spray them with breakaway or similar a day before.)
2) Starting with the bleeder futhest away from the master (pass. rear), open it about 1 turn. You can put a little hose and cup on it if you want to keep the old fluid from running all over. Make SURE to keep the master cylinder topped off with fluid and DON'T let it get down to where air gets back into the master cyl. Let it flow this way until the fluid comes out of the bleeder clean. This will take at least 2 cups or so of brake fluid. Using gravity alone, you can drink 2 beers while topping off the master cylinder for the first corner. (CAUTION: Do not store brake fluid in beer cans or put beer into master cyinder. Drinking a little brake fluid however will probably not kill you. Beer in your brake lines might.) Snug up bleeder good when you're done.
3.) Proceed to drivers rear and repeat. It won't take as long because the long brake line has already been purged of the old fluid. So you have to drink your beer faster.
4.) Pass front. Drink even faster.
5.) Drivers front. Etc.

Patience can be substituted for beers, but that's no fun.

This prevents the rubber pieces from going any further than they are used to and self destructing.
:cheers: "
 
Gravity bleeding works fine too, but beer makes me fat. I tend to get impatient and get to doing something else and realize that I forgot to check the fluid. When I was regularly driving an old Mercedes, which uses vacuum for just about everything but the radio, I had to get the pump anyway, so I always have one on hand.
 
Thanks for the advice guys. It seems like bleeding is so easy it is hard to find info to do it. I like the gravity idea the best, i'd rather not mess with the vacuum kit because id always second guess myself with the amount of fluid that i pump into the line. I'll grab another caliper too for the passenger side. Windy and freezing tomorrow, its gonna suck makes me happy spring is near.
 
Thanks for the advice guys. It seems like bleeding is so easy it is hard to find info to do it. I like the gravity idea the best, i'd rather not mess with the vacuum kit because id always second guess myself with the amount of fluid that i pump into the line. I'll grab another caliper too for the passenger side. Windy and freezing tomorrow, its gonna suck makes me happy spring is near.
Just to clarify, with vacuum you pull the fluid out of the line through the bleeder. You could think of it as "assisted gravity."
 
I finished it up and bled the brake with someone pressing the brake pedal, it wasn't that hard. I got on the road and the vibes were still happening. I was about to get U joints but i went home and took the front driveshaft out and the vibes were gone. It wasnt a complete waste that i put in a new hub it was probably going anyway.
 
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