First timer on brake pads and rotors - tips requestged
 

Hi Pelicans - I am going to replace pads and rotors for the first time on my '83SC. I have reviewed 101 Projects and Bentley, but I will not shy away from the wisdom of this board!

I've had a flush on fluid done recently, but the pads and rotors are the same as those on the car when I purchased it in 2012. I've also had the rubber lines replaced with the stainless braided ones from our host, I think the rubber ones were original to the car. :eek:I don't think I have any problems with the brakes, but this is a job I've been meaning to get around to. At a minimum, the pads are on the downside of good.

What are best practices here, and things to look out for/things you wish you had done the first time? For example:

1. Will I need to re-do bearings on either front or rear?
2. Which calipers can I hang without disconnecting the brake lines, and which do I need to separate?
3. I don't have new bearing seals - should I wait until I do?
4. Advice on bearing grease to use?
5. Things to look out for on the rears with the parking brake shoes?

I may have missed some items...Thanks as always for the advice, Pelicans!

It's a good time to repack your front bearings. Have the bearings and outer seals on hand in case yours need replacement (they're cheap). It would also be nice to have new set screws for the rear rotors.
Rears bearings are sealed and should be left alone until they go bad. (unless you're a masochist)
You'll probably need to briefly disconnect each line in order to move the calipers out of the way.
Everyone has their own grease preference... I like Redline CV-2.
No issues with the parking brake.

Bearings/seals questions: To check the bearings, raise the car, grab the wheel at 12 and 6 and gently rock on the vertical axis. If you feel play, it's time to replace. Otherwise, clean and repack the rollers and replace the grease seal. It's an easy DIY to replace them but frankly, well adjusted and greased front bearings rarely wear out. As for seals, the our seals fit other cars too. My local parts store had them in stock, $6 each. If you see grease on the inside of the hub, replace before reassembly. Grease is getting out and dirt is probably getting in.

You can't service rear bearings. They are pressed in as a unit.

Lots of folks use a coat hanger to suspend the caliper. You shouldn't hang it from the brake fluid line.

Grease? I'm on my second tub of the Valvoline synthetic wheel bearing grease and haven't had a single front wheel bearing failure. Any good quality WB grease from your local parts store should be fine.

In my sample of Porsche rear brake shoes (1), I didn't have any problem removing the hub. I think it's because they are normally either on or off, they don't wear nor will you get the typical "lip" preventing hub removal. Hope yours are as easy to remove as mine.

the fronts require discon the line. on the rear remove the big clip that secures the hard line then you can fish the line through there as your taking off the caliper. tip on removing the clip- get a pair of vice grips on the upper lip then position a screwdriver under the vice grips right where it grabs the lip and hit that w/a hammer upwards. its really not a big deal if you discon the line. ive bled my brakes w/the gravity feed method a bunch of times w/no problems check it out. on the front bearings there are a few ways to go. u could just put a new disk on and put it back together. i would take the opportunity to completely repack the whole shebang. if you have never adjusted a wheel bearing, do some reading on the procedure

Here is a tip about hanging the calipers with hard brake lines. I was confused at first.
http://forums.pelicanparts.com/porsche-911-technical-forum/867446-parking-brake-adjustment-stuck-caliper-removal-hard-line.html

Thanks for the advice guys, I'm sure it will be a big help!

When you reinstall the calipers make sure the bleeder is at the top-
Also steel braided lines are so cheap- good time to do them

Full youtube vid on wheel bearing regrease. Also show dismount of calipers etc. You might find it helpful for what you are doing.
https://www.youtube.com/watch?v=9QcqqoDh2io

I did not disconnect calipers to replace the discs....remove the line locks/stays and suspend the calipers ( I put mine on an extended jack stand)...this works on the rears too if you take your time and are careful.
If your brakes need flushing anyway then disconnect.
Test your front bearings and visually inspect. Repack with the proper grease.
Use a tire/wheel when tightening bolts on the disc...just lay it in there and you've a perfect 'holder'. Just make sure everything is spotless first.
Getting the front grease caps off can be a bear....I use a muffler C clamp on the cap to get a good purchase to pry it off...use wood between your pry bar and whatever surface.
You will not need any new seals unless you change out your front bearings...just don't bang things around.
Reseat the front spindle/disc unit a few times to seat it properly...there are a few threads on getting the setting just right.

Use a micrometer to check the disc thickness is several areas. If they are grooved, you can have them turned, but it might be cheaper to just replace them if they are getting close to the minimum thickness. This is covered in the 101 book.

When you compress the pistons back into the caliper to fit new pads, take note of the pad thickness. If you have one especially thin pad and the piston is harder to push back in than the others, this likely indicates a sticky piston, usually from corrosion. You can rebuild them yourself, but worn out plating in the piston bore may be the problem, in which case, you should get the calipers "restored". I and many others have had good results with Eric at PMB.

Definitely repack the bearings, or replace any that show pitting, scoring or brinelling.

If the fluid hasn't been flushed, (not just bled), within the last year, do yourself a favor and replace the fluid.

With an old master cylinder, or one of unknown age, I would advise against manual bleeding of the brakes, because after a while, crud and vicious trash build up in the MC bore at the limit of normal travel, so when you hop in and push the pedal to the floor, during bleeding, the piston rubber seal tries to ride over that "stuff" that has been pushed up to a point in the bore and in riding over or through it, the seal is cut.

This leads to a pedal that creeps to the floor with constant light pressure. If you slam the pedal, it will likely seal, but mild pressure isn't enough to retain the fluid and you have a "creeper".

While working in a dealership, I was frequently drafted for brake pedal duty and noticed a disturbingly high number of master cylinder "Fails" right after bleeding.

Motive, gravity or vacuum bleeding avoid this issue.

Buy good not cheap pads. Consider what your upcoming use is likely to be and buy accordingly. Stock OEM is the default minimum quality level.

I have not yet enough experience to offer sound advice on pad choice.

good luck,
chris

OK, so here's how things shook out for me:

1. Plenty of meat on the pads
2. Rotors looked fine, no scoring but plenty shiny. Didn't take a measurement on the rears but the fronts were fine.
3. Tried to replace the rears first, but couldn't get the calipers off due to frozen bolts - can I use Kroil in this area?
4. It was sunny, and since the pads were fine - away I went in the p-car for a fun drive!

So, I do want to replace the rotors, but the stars didn't line up to allow easy removal of the calipers - any best practices to share on this point - wrench types, penetrating fluid use, etc.?

Thanks, Pelicans!

Yes, kroil on the two bolts is okay just concentrate the spray on the bolts.

I use two box wrenches method the very first time. It is a real tight space but it can be done.