Source for rebuilt front calipers?

[m5bb]

I have looked many many places for rebuilt calipers.
Currently my right front has two pistons that work and two that are stuck.
The pistons won't retract because they are stuck in the cyls.
I have rebuilt many calipers but can see that these have been rebuilt before. Wonder about the tolerances?
If a manufacturer rebuilds them they would have to meet specs so they could be replacing the pistons if necessary to meet specs. I don't have those resources for new pistons?

BMW sells new ones for over $300 each. Ouch!

I've searched this site to see if there is any crossover to other BMW models but haven't found anything?

I did find some of all places Autozone. someone mentioned that in a related post. They are $59ea. the core is $27 Reman by Cardone?
Anyone use these?

Gary

 

[Luis A.]

I just rebuilt my rear ones. One of the cylinders in each caliper was firmly stuck and required several applications of ATF/acetone and vise gripping of the top lip, avoiding the polished surface, to get them free. They were perfect. No rust. A thorough cleaning and scrubbing with the 3M scrub pads and they were as good as new. A new set old seals is all it took. Don't make a decision until you pull out the pistons.

 

[jamesw]

I tried buying new front calipers but couldn't find them. I ended up buying some rebuilt ones from Mesa Performance. They send them out to get rebuilt - they don't do it themselves.

I have rebuilt calipers before and it's not that hard. It's just messy and takes time - something I just don't have right now w/ a one year-old.

HTH
James

 

[CSLCOUPE]

Remove the pads, and pump the pedal till all the pistons are against the rotor, (then there 90% out). Remove caliper and the pistons will come out with ease. The bore usually rusts from the piston seal to the dust boot. If the pistons are not pitted, there fine.

 

[HB Chris]

+1 for Mesa, they send them to Centric for rebuilding, just did my fronts. I bought the BMW bleeders, one of the replacement bleeders didn't seal well.

 

[m_thompson]

I just rebuilt the rear calipers for the second time in 30 years. I replaced the pistons this time because they are not too expensive.

 

[m5bb]

Remove the pads, and pump the pedal till all the pistons are against the rotor, (then there 90% out). Remove caliper and the pistons will come out with ease. The bore usually rusts from the piston seal to the dust boot. If the pistons are not pitted, there fine.

I took the caliper off the rotor and put blocks of wood in place and then pushed the brake pedal. That's how I determined 2 pistons (one side) was stuck.
I now have the caliper off the car and split into two halves. Didn't finish but was in the process of getting the stuck pistons out.
I'll see what they look like and then determine if I need to replace.

m thompson, where did you get pistons?

 

[m_thompson]

m thompson, where did you get pistons?

http://www.wallothnesch.com

 

[m5bb]

Oh, across the pond.
Thanks

 

[HB Chris]

Since you split the calipers be sure to get the new o-ring seals for the bolts, I think only W&N sells them.

 

[CRJ Driver]

Had mine rebuilt by local NAPA. They send the calipers off to a commercial rebuilder in Philly that splits and reworks, bench tests, etc..the parts using machines us mere mortals don't have access to. My finished calipers for all four corners are as new, maybe better. Around $40-50 a corner if i remember correctly.

 

[americium]

After getting turned away from the last place where I bought a full set of rebuilt calipers, BPS, I found a replacement for a front left leaker at Autozone. Like you said, it was about $60 and has a lifetime warrantee. (right...)

It's been on the coupe for about a year now, no issues. Of course it's not a high performance caliper but it seems to be adequate.

 

[m5bb]

Since you split the calipers be sure to get the new o-ring seals for the bolts, I think only W&N sells them.

There are other resources for those, locally.
Try this.

http://www.mcmaster.com/#o-rings/=i9cm99

 

[stphers]

Calipers

You must be careful using the proper O ring, it must be compatible with brake fluid and a normal o ring will not work. Caliper o rings are " square " cut, not round.

Have rebuilt a lot of calipers as a tech and have never seen these o rings come in a kit, most times you can reuse them as long as you don't damage them

Thanks, Rick

 

[m5bb]

After rebuilding my two front calipers I am having a dragging issue.
I bought rebuild kits, used a cylinder hone and polished the pistons with 600 grit emery paper. Cleaned and painted and then reassembled.
Pressure bled system and checked that pistons were moving with blocks of wood substituted for the pads. Good to go. All pistons extended.
Now when I first drive and things are cool its fine but after everything gets good and warm the left front in particular is dragging.

So I looked at all the brake lines and discovered that all are stainless steel.
Who knows how old though???
Can stainless steel lines develop the same inside collapse problem that rubber ones do?

BTW rebuilt calipers are becoming very difficult to find.

 

[wmnewlife]

rebuilt calipers

I ordered fronts from Autoparts Warehouse http://www.autopartswarehouse.com/shop_parts/brake_caliper/bmw/3-dot-0cs.html about $50 each. I'll let you know how they look. They should be in within the next couple of days. Dummy McDumbo ordered and received rears for my drum to vented rear conversion. Turns out they sent what I ordered - solids. If you want those, let me know. My office is in Sandy Springs, and I live near Emory. Walter

 

[sfdon]

Stainless brakehoses will and do go bad just like all rubber ones.
What is worse is that the stainless sheathing keeps you from seeing the condition of the rubber inside.

 

[m5bb]

Stainless brakehoses will and do go bad just like all rubber ones.
What is worse is that the stainless sheathing keeps you from seeing the condition of the rubber inside.

New SS hoses I have looked at say they are teflon inside. Not subject to collapse?

So you are sure the old ones were not teflon?

 

[MMercury]

New SS hoses I have looked at say they are teflon inside. Not subject to collapse?
So you are sure the old ones were not teflon?

There are rigid brake lines and flexible brake lines/hoses. It is probably a misnomer to refer to stainless steel flex lines, when the lines/conduit/hoses are clad in braided stainless steel - permitting flexibility. It is also probably a misnomer to refer to lines as teflon rather than a teflon-impregnated plastic or being teflon-coated.

My experience with lines (DOT approved and ahem . . . otherwise) is that the stainless clad hoses can be kinked, torn, overstressed, maltreated or poorly manufactured. Most "failures" are from leaks at the crimped threaded ends or obvious physical damage to the flex lines. Cut one apart or observe them being made and you may notice some have a plastic tube covered by the stainless braid. Once the stainless weave is broken, the protection is minimized, and who knows what may result due to sharp abraded stainless threads. But that is another story.

I suspect your braking issue is not related to the flex lines, especially if they do not evidence leaking or damage, i.e., "kinked." IMHO, even though you may have carefully rebuilt parts of the system, it is more likely you have a hang up with a moving part (caliper), or unforseen air or contaminants in the system. (I might feel differently if you were using older reenforced rubber hoses, which can balloon/swell under pressure but look perfectly normal in a static state.) This is particularly so, since you mention the issue appears when things are "warmed up." "Warmed up" carries with it the implication that brake fluid temps are “hot.” New brake fluid is designed to function at these higher operating temperatures. Older or contaminated fluid may not react the same way, which underscores the necessity of periodically refreshing/replacing it and purging the system of all contaminants - including air. Of course metal moving parts that have a tendency to expand when hot may function differently when hot. Ergo, you may have tested a caliper under pressure, but like pudding, the proof is in the eating (or braking and “baking”) rather than pressure testing on the bench.

Is it possible that your braking issue only seems like a sticky caliper? Glazed rotors, contaminated pads, mismatched pads, mismatched brake hoses, uneven road surfaces, tire issues, and even alignment settings can seemingly affect braking.

Coated Teflon® inner core


StopTech® brake lines consist of a PTFE (commonly referred to as Teflon®) inner line that carries the brake fluid, which is then covered with a layer of stainless steel woven braid. The PTFE tube is very resistant to expansion under pressure and maintains integrity with exposure to corrosive brake fluid.http://www.stoptech.com/products/stainless-steel-brake-lines

 

[m5bb]

There are rigid brake lines and flexible brake lines/hoses. It is probably a misnomer to refer to stainless steel flex lines, when the lines/conduit/hoses are clad in braided stainless steel - permitting flexibility. It is also probably a misnomer to refer to lines as teflon rather than a teflon-impregnated plastic or being teflon-coated.

My experience with lines (DOT approved and ahem . . . otherwise) is that the stainless clad hoses can be kinked, torn, overstressed, maltreated or poorly manufactured. Most "failures" are from leaks at the crimped threaded ends or obvious physical damage to the flex lines. Cut one apart or observe them being made and you may notice some have a plastic tube covered by the stainless braid. Once the stainless weave is broken, the protection is minimized, and who knows what may result due to sharp abraded stainless threads. But that is another story.

I suspect your braking issue is not related to the flex lines, especially if they do not evidence leaking or damage, i.e., "kinked." IMHO, even though you may have carefully rebuilt parts of the system, it is more likely you have a hang up with a moving part (caliper), or unforseen air or contaminants in the system. (I might feel differently if you were using older reenforced rubber hoses, which can balloon/swell under pressure but look perfectly normal in a static state.) This is particularly so, since you mention the issue appears when things are "warmed up." "Warmed up" carries with it the implication that brake fluid temps are “hot.” New brake fluid is designed to function at these higher operating temperatures. Older or contaminated fluid may not react the same way, which underscores the necessity of periodically refreshing/replacing it and purging the system of all contaminants - including air. Of course metal moving parts that have a tendency to expand when hot may function differently when hot. Ergo, you may have tested a caliper under pressure, but like pudding, the proof is in the eating (or braking and “baking”) rather than pressure testing on the bench.

Is it possible that your braking issue only seems like a sticky caliper? Glazed rotors, contaminated pads, mismatched pads, mismatched brake hoses, uneven road surfaces, tire issues, and even alignment settings can seemingly affect braking.

Great info and confirmed my suspicion about the SS flex lines.
None are leaking or damaged.
Fluid is new ATE super blue. But i need to bleed the back calipers again.
I will take apart the caliper again if necessary.
Dragging is the proper term. I drove about 12-15 miles yesterday earlier when cooler and then home in 95+ temp. (HotAtlanta)By the time I got in the driveway I did not have to step on the brake on a small hill as the left was dragging so much it would hold the car. Brakes were not pulling on the highway or anytime just slowing the car down. I could feel it.
I have rebuilt brakes for years. This is a first for me.
Also a new MC was installed about 3 years ago by PO.