one caliper needs a rebuild... rebuild them all?
 

ok. i've had my 911 for 8 months and have done lots of baseline maintenance and some nice upgrades. I'm getting some occasional moaning out of the left front that appears to be a caliper.

If I rebuild the caliper, should I pull them all? (115k) anything else to do to the brakes while i'm there?

stainless lines... new fluid... anything else?

when do i resurface the rotors? (some are smooth, others have slight grooves).

thanks for any comments!

-Bernie

Check the puck orientation in the calipers, I've heard that they can groan if they get rotated out of position when pads are changed, at least I was warned about it 20 years ago on my '79.

If you do need to rebuild a caliper, I would recommend rebuilding the other caliper on that same axle. You want both wheels on any given axle to have the same level of braking performance otherwise you will pull to one side. Having one wheel rebuilt and the opposite wheel left alone would make me nervous. If the other axle seems OK, I would not worry about it. Pull out the brake pads and look at the rubber seals to check their condition.

You'll want to change your fluid as part of the rebuild process. If your current brake lines are not expanding on you, I wouldn't worry about changing them. It can wait til later.

I just did all 4 of mine. One of the problems with the pucks is that they get frozen. I would agree with jakermc and rebuild the other caliper on that same axle. Also check the master cylinder and replace it if it shows any signs of leaking. If that is necessary, you may want to replace the lines at the same time.

Bernie, I would say rebuild all 4 and change the lines (you can't tell from the outside what's happening on the inside). This will give you a good base line and peace of mind, better safe than sorry with brakes. I just did mine (rebuilt all 4, new DOT stainless lines, new fluid and pads), it is not a difficult job. Your rotors should be fine if the are within specs and not lurching when you stop, the specs should be engraved on the rotor. If within specs and not grooved too deeply, take the glaze off the rotor with a piece of sand paper sanding in a circular motion. You can also paint the calipers and rotor hats and edges while you have it all apart. Don't forget to repack your front bearings while your at it.

That all makes pretty good sense. I'll just redo the front two for starters, new fluid, maybe replace the front lines while i'm there. Thanks folks.

Can someone recommend a good book on how to do a brake job. I'm getting ready to do my fronts and would love some advice with pictures.

The one and only.....

http://www.pelicanparts.com/cgi-bin/autocat/load_page.cgi?page_number=1&bookmark=2&model=911E& currsection=documt

Not only brakes but plenty more! Order here and you get a bonus CD and if you're lucky Wayne will sign it for you. Better yet, one signed copy for the book collection and the other copy for the garage.

http://forums.pelicanparts.com/uploa...1068130293.gif

Ummmm, speaking as The Board's most notorious cheapskate, I think you should consider a broader brake overhaul strategy. A caliper rebuid kit is, what, $15? C'mon. As long as you've got the system "open," why not do the rears at the same time. Cost you just a few extra bucks. Takes just a little more time. Taking the glaze off the rotors is a good idea. Taking them to a brake shop for inspection/measuring/turning is even better. And even if you end up getting new rotors, you're still going to pay WAY less than shop brake work costs. And from there, if you replace or rebuild the MC and replace the lines, then you have brand new brakes that will work perfectly and not need attention for quite a while. Rebuilding brake parts is a small pain if you do it once. A larger pain if you do it two or more times because your first job was not a complete one. Just a suggestion. In truth, a partial, one-axle brake job is something you can probably get away with.

Call me crazy (and you'd be right), but I consider brakes to be an important safety system.

Here are a couple good Pelican Tech Article with pictures to get you through pad replacement and caliper rebuild: http://www.pelicanparts.com/techarticles/911_caliper_rebuild/911_caliper_rebuild.htm

http://www.pelicanparts.com/techarticles/911_brake_pads/911_brake_pads.htm

na2ub, the DOT stainless lines are approved by the Department of Transportation, the others are for racing and off road use only. I don't know if there is any actual difference but with brakes I would rather be safe than sorry.

I just did this not to long ago. I had a sticking caliper on the front. Just did the one axle - but replaced everything for piece of mind. New bearings, Lines - different views for SS vs OEM - replaced the rotors (they are pretty cheap) and pads and fluid. I got speed bleeders and didn't even use a whole can to firm 'em up.

Checked the rears and they were not even 30% worn so didn't touch them.

http://forums.pelicanparts.com/uploa...1068131464.jpg

Jeremy, somebody has to talk to you about keeping your carrera clean. It doesn't look like your wheel wells have been waxed in weeks!

Thanks cassisrot - actually this is one of the benefits (to me anyway) of doing this yourself. I got to clean the crap out - polish the hubs, paint the calipers (yes a little bling bling) etc. No mechanic is going to do that for you during a brake job.

A few items to consider when doing this job - hints that were passed on to me that I will now pass along (and sorry I don't remember who told me what or I'd give you credit) - Hubs - heat 'em up on a BBQ grill to get the old races out when you install new bearings. To get the dust cap off the hub (and mine was a b!tch to remove) use one hammer with the claw on the lip of the dust cap and strike the head with the other hammer (worked like a charm) To install the new races - seperate them from the bearings and stick in the freezer. Warm the hub and beat em in! Thom (widebody) has a great how to that I printed out the pictures and it helped me with the sequence Link

That is all

PS - you want to see clean, check out Kevin's (KTL) ride.... SmileWavy

Quote: "PS - you want to see clean, check out Kevin's (KTL) ride...."

That's for sure.

Absolutely do them all. Replace the hoses, and you probably want to rebuild or replace the MC too.

You can bet the seals are shot on all 4 calipers. The parts are cheap, better to get the whole system solid and safe and avoid repeating the work down the road.

What Chuck said.

Get your protractor out to make your own template for aligning the piston when you put it back in. Use some thick card, or quarter inch plywood, etc. I used a piece of foam core I had lying around.

Do them all. This is one of the least expensive and easiest thing you can DIY. I did this 2 years ago on a Saturday at home. Doing them all gives you piece of mind and a good baseline. Porsche brakes are some of the best out there.

OK... I'm doing them all. I pulled the pads front and back and took a look at the seals... not pretty. So, more questions after reading 101 projects...

Is it possible to get the caliper pistons out without compressed air?

Yeah, don't disconnect the caliper from the hardline. Leave it connected and alternate clamping one piston then the other on the caliper while pressing the pedal in between changing the clamp from side to side worked great on my frozen piston.

Just like it's detailed here:

http://www.pelicanparts.com/techarticles/911_caliper_rebuild/911_caliper_rebuild.htm

I used a bike pump and cut the valve off an old inner tube. Leave just enough rubber to seal around the caliper inlet.

Took about 30 psi to get my pistons moving. Use a C clamp to hold the other piston. 30psi x 2.5 in is 75 lbs force so don't use your fingers.

PP sells caliper grease which will make this rebuilt last a while.

What about replacing the roter? I've never replaced the roter, repacked the seals, etc. That's where I'm interested in learning how to do. The pelican articles are great for the caliper rebuild. Should I clean the bearings and reback? If so, what do you clean them with? Anything I should be cautious about before I begin.

Get new bearings - they are cheap. You have to replace the races (the part that the bearings ride on) they come with the berings and are matched. Heat up the old hubs on the BBQ grill and pound out with a flat punch or a bearing remover (I think KTL knows of a specific bearing remover for $30 bucks at Pep boys that will work so you don't have to beat the races out!) Wish I would have know about that before hand.

Freeze the races, heat the hub back up and drop the races in the hub. Then repack. I was a little intimidated by that too but it was actually pretty easy. Just be careful with the hubs as they are aluminium and will get beat up pretty easy.

tt_targa... i think i'll go that route first... thanks for the suggestion.

mtelliott - replacing the rotors is simply a matter of getting the caliper clear and unbolting the rotors. The bearings are a little tougher and the hot/cool method helps(There was something a little satisfying about getting the webber grill up to 600 degrees), but i'm gonna get a cheap bearing remover (per KTL) the next time i do it.