front ABS brake caliper piston retract

All you need do is use a C-clamp to push the pistons back inside the caliper housing.

If you are careful, you can wedge an appropriate prying device between the caliper and a brake pad, and force the caliper open by prying. (You have to be cautious so as to avoid scratching the rotor.)

Speaking of rotors, did you measure them to be sure they are not worn to the minimum spec that is printed on them?

As said, it just shoves back in but the recommended way of doing ABS equipped cars is to open the bleed nipple and force the fluid out of there rather than back through the master cylinder. Also makes it easier to push back in by hand, though an assistant is helpful to stop you drawing air back into the system.

Or er damaging the seal, but this may depend on model.

Not necessarily. Back in the dark old days when I drove a Bummer (up to last year), unless the calipers were original (which I could easily push back in) these things will freeze out, and they simply won't budge. I'm a strong guy to begin with, but even a big C clamp didn't do the job with the fluid bleed open.

Oh, the memories. A list of problems over those 8 years that was literally half as long as my arm, including the shitty GM transmission they put in the "ultimate driving machines" going south at 85K miles--nearly $4 grand to replace. I drive an '09 Honda Accord now. Pure bliss and looking forward to years of bliss!

Why read a BMW group then? Obviously need persuading you made the right decision by your posts...

Just thought I'd drop in. I read lots and lots of stuff. I became a bit of a Bummer expert during ownership.

This group looks like it's dying, like a lot of USENET.

But you obviously think Bummers are great cars.

Doesn't sound like it by your advice about calipers. If they seize as you suggest there'd be lots of other problems. And why wouldn't they be original - they have a very long life.

BMW, like any other brand, isn't perfect. But usually enjoyable to drive

- unlike most Hondas.

Yeah, like their transmissions, and their electronic components, and their blower motors, and their cat. converters, and their rubber molding, etc., etc.,etc.

The Accord drives fine. Like most Hondas, it's very light on its feet, although it's actually a pretty heavy car--the Accord is considered a mid-sized car now. And it is a HELL of a lot more comfortable than the bummer was.

Not had a problem with any of these on my 10 year old E39. Except the final stage resistor - easily changed.

But hey - if reliability is the only important thing for you - you're probably right in buying a Honda. Or Toyota. Everyone has to retire and slow down some time.

As others have suggested, use a C clamp and screw the clamp down on the piston top to settle it back down into the shell (brake housing we say in the colonies).

The brake fluid squeezed it down that way as the brake pad linings wore away from use.

Sooooooo ... you have to give the brake fluid a place to go back up the pipe it came back down (some people loosen the brake fluid filler cap), and drain out ALL the old brake fluid.

Flush out the system, the pipes and all down to the refurbished brake shoes ... it is full of dirt and rust, makes for pitting in the master cylinder miles later ... so use DOT 3 or what ever BMW recommendes as brake fluid ... get a whole liter or quart ... save off what you expend and recycle it. Rather toxic so be mindful.

Go slow, don't scratch things, clean it up nicely, and follow the steps in the shop manual you zeroxed out of the public library ... and it will do rather nicely.

Penny wise is dollar foolish on a BMW ... so use good parts and use all the BMW stuff they say to use or better if it is on the shelf.

Sumbuddie hopes this helps

:?

Jane Earnshaw wrote:

Hondas are OK, for FWD cars. I'd love to see them do a 3-series comptetitor. I think they could hit the target better than what Lexus (and Mercedes, for that matter) has been able to do...

Try changing the brake fluid once in a while. Works for our bimmers thus far.

My '91 Accord now has over 210K miles. It also has original calipers and wheel cylinders.

Original calipers? Big deal.

I've been working on cars (shadetree stuff for my own fleet) for 40+ years and never replaced a caliper.

My first BMW topped 225K miles on the original calipers. I've had Hondas that were closing in on 200K miles with no reason to think the calipers were going south.

Brake fluid makes sense though ...

.

It was an *example*. The point is this: Brake fluid is hygroscopic. If you don't change it, water vapor eventually gets past the seals (even if they are good, they are rarely perfect). When that happens, corrosion starts. I've replaced any number of calipers that were corroded, many of which would not retract. After the first time it happened to me,

30-something years ago, and I started to change brake fluid from time to time, none of them have been mine.

(So far, the record for me is 264K on a 1972 Datsun 510. The Accord and our two E46s might very well break that record handily if we don't hit too many deer with them....)

Where did I say I didn't?

If you had lots of problems with calipers seizing, it's the likely cause.

Was that a "Steptronic"?

Doubt it makes much difference to the replacement cost.

Any guesses as to why BMW used GM transmissions on US cars, but ZF pretty well everywhere else? Especially if the GM wasn't reliable?

ISTR reading that engine/gearbox combos had to be type approved in the US which cost mucho-wonga. Perhaps using a home grown box got round this somehow.

Alternatively, perhaps the ratios were better suited to US driving. Fifth on my ZF boxed 325 was so long that it probably wouldn't have got into it at 55mph[1].

[1] Don't forget, this is 15+ years ago. I know limits are higher now.