Caliper Swap DIY?

[LVDell]

I have seen DIY's for brake pad swaps, rotor swaps, etc.....

but no Caliper swap DIY. Anybody have one for a 996 (mine is a MY00)

I am replacing my blacks with reds (same calipers just red) and want to make sure I don't screw this up.

Looking for a DIY that covers the swap AND torque recommendations for the bolts, etc.

Thanks!

Dell

[ar38070]

This is straightforward just messy.

Once you remove the caliper from the wheel carrier you disconnect the brake line and then attach the new caliper.

The torque for the two bolts that hold the calilper to the wheel carrier is 63 ft-lbs. The torque for the brake line to the caliper is 9 ft-lbs.

Now you need a power bleeder to purge the air from the system and a liter of fresh brake fluid. With the power bleeder hooked up you start with the caliper furthest from the reservoir and work your way closer. Do not forget that there is a bleed screw on each caliper (8 total). You start with the right rear, then left rear, right front and finally left front.

[LVDell]

Anything a bit more detailed? I am going to need to swap EVERYTHING over from the old calipers to the new and want to make sure I do everything correctly (and in order) so I don't screw this one up.

By the way, thanks for the reply (it was informative but I guess I am more of novice to the brake systems and need a bit more spoonfeeding :wacko: )

Thanks for all your input!

Dell

[Loren]

Your calipers should come complete and ready for installing and bleeding. After swapping them it is just a matter of bleeding them. Have you done that before? Do you have a power bleeder (like the Motive) ?

[LVDell]

I do have the bleeder (bought a motive last week from PP at 20% off). So you are saying the calipers will already have pads, sensors, etc? I ordered the factory OEM reds:

996 351 425/6 11

996 352 421/2 13

Thanks Loren

:cheers:

[Loren]

No pads or sensors. Just swap from the old ones to the new ones.

[KarlS]

OK, I'm doing this from memory, so you guys double check me to make sure I didn't forget anything.

Here are the steps for a caliper change:

1. First, disconnect the sensors and remove the pads using the pad change DIY.

2. Loosen the two hex head bolts that hold the caliper to the wheel hub. I think these require a 10mm hex head socket. I recommend a 1/2" Snap-On socket because the 3/8" ones you get at Sears will sometimes snap when trying to loosen the bolt. You'll also need a big breaker bar to break the bolt loose.

3. Before completely removing the 2 bolts from the wheel hub, remove the 10mm bolt that secures the front brake line to the wheel hub. Note: this step is only required for the front calipers.

4. Have a short bungee handy so that you can hang the caliper from the spring so that the brake line doesn't crimp. Finish removing the 2 hex head bolts and hang the caliper using the bungee.

5. Before removing the brake line from the caliper, you may want to pick up some rubber brake line plugs from the local auto parts store. Plugging the line once you remove it will help minimize the amount of brake fluid you spill on the garage floor.

6. To remove the brake line from the old caliper you need a flare end or line wrench, either 10mm or 11mm, I can't remember which. A flare end wrench is a special type of open end wrench that wraps around 5 sides of the fitting so you don't strip it. Don't cheap out and try to do this with a regular open end wrench. You will surely strip at least one brake line and getting that fixed will cost a lot more than buying the right tool in the first place.

7. Loosen the brake line fitting where it connects to the caliper with the flare end wrench.

8. Remove the fitting and plug the end with a rubber plug to keep it from dripping all over.

9. Remove the old caliper.

10. Mount the new caliper on the wheel hub by just starting the 2 hex head bolts. Before inserting the bolts, coat the threads lightly with anti-seize compound. BTW, I think Porsche recommends replacing these bolts when replacing the caliper as they are only designed to be torqued once. I have reused them without problem but I wanted you to know what Porsche recommends.

11. Unplug the brake line and connect it to the new caliper. Tighten the fitting with the flare end wrench to 9 ft lbs, which isn't much. You probably can't get a torque wrench onto the fitting, so just snug it and make sure not to over torque it.

12. Screw the hex head bolts in the rest of the way to the hub and torque them to 63 ft lbs.

13. Reconnect the 10mm bolt that secures the front brake line to the wheel hub. Again, this step is for the front brakes only.

14. Replace the pads and sensors per the DIY.

15. Bleed the brakes. For a caliper change, I usually go around twice, just to make sure I get all the air out. You also should tap the calipers with a rubber mallet while bleeds to loosen up any air bubbles. Also check the brake line fittings to make sure there are no leaks while the system is under pressure.

16. Before moving the car, make sure you start it and pump the brake pedal until you get a hard pedal. DO NOT forget this step or you can end up running into something.

OK, so what did I miss?

BTW, if you find any of this confusing or don't want to invest in the proper tools, skip it and get a professional to do the swap. The last thing you need is to screw up your brakes and get in an accident as a result. If you're the least bit unsure, it is safer to have a knowledgeable pro do it.

Karl

[ar38070]

You forgot to take off the wheel. :lol:

When you put the wheel back on the torque for the bolts is 96 ft-lbs

1) Instead of disconnecting the sensors you can just hang the brake pads in the wheel well with a piece of wire.

4) Instead of a bungee you can use a coat hanger.

5) A pencil or sharpened piece of dowel also works as a plug. Brake fluid is nasty stuff. Do not splash any on the paint. Also you can put down paper or cat litter to soak up any that you spill

10) I have also reused the bolts without any problems.

[LVDell]

Thanks for all the input. I am off to get a couple more tools. I totally feel confident about this not to mention I am excited about it.

Couple last questions:

1. Reccomend putting the car on 4 stands and remove all 4 wheels at the same time or just put jack stands at the front and jack up the back, etc.? I am open for suggestions (the safest).

2. Dumb question, but is Anti-Sieze compound synonymous with Locite?

Thanks again All!!!!!

[Loren]

1. Whatever you feel comfortable with. For bleeding it is nice to go from caliper to caliper without stopping to remove a wheel.

2. No. Anti-seize is a high temperature grease that prevents bolts and nuts from rusting or corroding tight. Loctite is a thread sealer/locker (so they don't vibrate free). Almost opposite in purposes.

[LVDell]

Wheh! Glad I asked for clarification on the anti-sieze :)

I am thinking the 4 jackstand route is probably the best route to go? Best place to locate the 4 stands?

[her_986]

I would like to add to KarlS most excellent write up regarding #5. I have used plastic wrap to seal the master cylinder reservoir to help keep the fluid from leaking out when removing the break lines. I must admit that I have not done this on a ‘P’ car, but do not see why this would not work. Most likely someone will say why it would not. You could also use the power bleeder cap with the hose pinched off. The idea here is to seal off the vent hole that is most likely in the master cylinder reservoir cap.

Hope this helps…

[Orient Express]

Yeah, don't forget to put a drop of Loctite on each bolt when you reinstall them. The rest is a piece of cake.

[LVDell]

locite? didn't we just clarify that is BAD?

Locite=stuck bolts

Anti-Sieze=easier to remove next time (rust lock, etc.)

[TD in DC]

NOOOOooooo. Loctite good because your brake bolts will not vibrate loose. LV Dell, I admire your zeal, but I would consider letting a pro swap out your calipers given your questions regarding loctite and anti-seize :D Breaking a rear center console or replacing an exhaust at the risk of creating a leak is one thing, messing around with brakes is a whole other ballgame (unless you have the feet of Fred Flinstone). ;)

[LVDell]

Thanks TD. My post was more for clarification than anything. I thought it was odd that anti-sieze was suggested so my brain played tricks on me. I heard anti-sieze AND locite in the thread and want to make sure.

Karl said:

10. Mount the new caliper on the wheel hub by just starting the 2 hex head bolts. Before inserting the bolts, coat the threads lightly with anti-seize compound.

Understand my confusion?

Karl, did you mean locite? I can understand anti-sieze on the retaining pin...but the 2 bolts?

[my996]

Dell, to make this thread even more informative for the rest of us first-timers, could you please take pictures as you go and write about your experience? I know this will help me when I finally take the plunge. I would just like to see it done once so I know what I am doing. thanks - and BTW, great topic.

One last thing, a while ago I clipped an aritcle out of a Porsche magazine that described what is being discussed here. I think it was for a Boxter but the principle should be the same. When I find the article again, I will scan it and try to post it so it might be of assistance. :D

Tony

Edited August 10, 2004 by my996

[LVDell]

I was thinking of doing it with video (can make still shots as well with DV).

Please let me know if you find the article Tony.

Thanks all,

Dell

[Loren]

I was thinking of doing it with video (can make still shots as well with DV).

Please let me know if you find the article Tony.

Thanks all,

Dell

Wait... wait... a video... maybe ToolPants just found a good reason to go to Las Vegas ;) ;)

[LVDell]

Like anybody ever needed a reason to come to this town! :jump:

Karl/Anybody want to address the anit-sieze comment made in step 10?

[my996]

Please let me know if you find the article Tony.

Thanks all,

Dell

I'll start looking.

[her_986]

I think the work shop manual will have to be referenced to get the true story on this subject. As I find that what was said in #10 and #12 regarding the bolts to be lacking some information. Having said that, please let me explain, if the bolts that hold the caliper onto the car are truly ‘torque to yield’ bolts they would have a torque specification and a yield specification. Regarding the replacement of the bolts, I think that it is more of an insurance mater than a limitation on the bolts. These bolts live in a very harsh environment and are subject to all kinds of heat, water and dust that can contribute to wear on them. Also in my option, the manual is written with the idea that some kind of wear or tear, i.e. mileage/damage has occurred to the caliper that has caused the replacement of the caliper. And possibly overstressing/degrading the bolts. So the small cost of new bolts is cheap insurance against a caliper coming loose on a very expensive ‘P’ car. Plus, the cost for the dealer work shop to take the bolts and test to make sure that they still meet specification would certainly exceed the cost of new bolts.. Now, if someone tells us that these bolts are made of some kind of super duper metal coated with diamond dust then yes by all means have them test before replacing. Now, we are talking about YOU working on YOUR car and certainly you can do anything you want including putting anti-seize or Loctite on the bolts. The way I personally look at it, putting anti-seize on would mean that some time in the future you are going to be removing the bolts as, I have noted above they live in a very harsh environment, and this would make it easier to remove them again. Or glue them in (Loctite) for what ever added security YOU think it is worth. Well, this is MY $.02, so take it for what it is worth. I know that you want to do, the swap out, the right way and the best reference would certainly be the shop manual for your 996. Good luck and have fun and take you time….

[LVDell]

her_986,

Thanks for the input. THat is more what I was looking for. Like I said, I was confused when I heard conflicting statements regarding Loctite and Anti-Sieze. The car is not old by any means so I feel there is no need to change the bolts since I'm just doing an "upgrade" and not a damage replacement. I think with loctite and and proper torque I will achieve what is best for the caliper bolts.

As for the anti-sieze, it makes snese to use that on the retaining pin as that is something that will come out many more times for pad changes.

Thanks again for the input!!!

By the way, I will be taking my time on this one. I know it sounds as if I am comnig across as being a novice and asking for someobdy to "be my hands". That is not the case. Granted this is my first caliper swap and I want to make sure I learn from anybody's help/tips/etc. from their own experiences (which is what makes this forum so great) but how many caliper swaps did the experienced DIY'ers do before their first swap (make sense?)

Thanks again everybody!

Dell

[KarlS]

The shop manual is silent on putting any coating on the brake caliper retaining bolts. However, a visual inspection of the bolts in my car showed that they were coated with an anti-seize compound at the factory (a light silver compound on mine, probably OptyMoly or something like it). Since these bolts are subjected to brutal heat and cooling cycles and because you have steel bolts connecting with an aluminum hub (remember ionization from chemistry class?), I was always taught to use anti-seize so that you can get the bolts out again when you need to.

You definitely DO NOT want to use loctite or anything similar, at least not if you ever plan to remove the calipers again. The bolts will not vibrate out if they are torqued properly.

If you don't feel comfortable with applying anti-seize, the best thing is not to use anything, since that is what is implied in the shop manual. I will also reiterate that the shop manual is very clear that you should only use NEW bolts when replacing the calipers. They don't explain why but they emphasize this point several times. The bolts can't be tested, since testing them involves finding the point at which they fail.

It could be a liability concern or it could be that the engineers have discovered that the process of torquing them down and then breaking them loose weakens the bolts in some way. I know of race teams who change calipers many times a season but never change these bolts and I don't know of any failures.

Karl

[LVDell]

Thanks Karl, looks like it is just personal preference on the boards. So....I am thinking NO COATING on the bolts and torque to spec should be fine.

I just noticed you are in McLean. I just came to Vegas from there (going back in 22 months). Man do I miss that area!!! I went from green and plush to dry, colorless, and blah! This place is like serving out a jail sentence.

Needless to say I will be back ASAP.