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Rebuilding calipers


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Hey guys I am going to replace the o rings and dust boots on my calipers this weekend if all the parts arrive in time, I have done a lot of research on the DIY for removing the pads and calipers however I have some questions regarding the procedure that I can't seem to find a definitive answer on, they are;

 

 

1) Should I remove some brake fluid from the reservoir before starting? Where should the fluid level be before removing the calipers? 

 

2) Should I leave the brake pedal where it is or place something against it pressing it down slightly? 

 

3) When removing the brake line from the caliper I assume some fluid will come out, will this stop at a certain point or continue to pour? Should I tie a small plastic bag around the ends? 

 

4) With the front vibration dampeners & rear spider things on the back of the brake pads, some ppl say leave them off while some put them back on, what do you recommend? and do I need to apply a adhesive to get them back on? 

 

5) Do I need to use brake pad grease when reinstalling the pads? 

 

6) My brakes tend to squeal when coasting to a stop, is there something I can do to the pads while I have them off to stop this? Like applying something to the surface or sanding it with some fine sand paper? 

 

7) After reconnecting everything and before doing the bleed I assume there would be air in between the brake line caliper connection through to the brake pistons, inside the caliper, how do you get this air out or will it just fill up naturally when you bleed?

 

 

Thanks guys I really appreciate your help! :)

 

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You obviously haven't done a job like this before and if it does not go smoothly you might end up with a problem that you cannot solve in your driveway.

 

You will need to get the calliper off the car and on a bench to make the job easier. I don't think the pistons will come out with the calliper still connected to the hub carrier.

 

Sometimes the calliper bolts don't come out that easily and can damage the internal threads on the hub carrier.  This happens when the end of the carrier bolt has corroded and when it is undone it mashes the internal carrier thread.   If this happens to you, you might need a new hub carrier - take care.

 

The way to stop too much fluid leaking out and to retain fluid in the M/C and system is to put a brake line clamp on the flexible hose and layer of plastic sheet under the fluid reservoir cap.  Also bleed each corner as you do the work.  You will also need to bleed the complete system after you have completed the job.

 

The easiest way to get the pistons out is with compressed air applied to the hydraulic inlet or bleed nipple port. When you do this the piston will fly our at great speed and can cause personal injury and damage to whatever it hits.  You should cover the calliper with a shroud of some type to catch the piston. Also DO NOT put your fingers in front of the piston when you apply air pressure as the emerging piston might cut your finger off when it jams it between the circular rim of the piston and the opposite side of the calliper.   

 

Hope the job goes smoothly.

 

.   

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Hi Hilux. Thanks for your reply.

 

I am removing the calipers from the car. Completely stripping them. Might even paint them speed yellow if I have the time. I have already bought new caliper bolts and locktite threadlocker to reinstall them. I have also bought a 150 psi air compressor to blow the pistons out of the calipers. 

 

So a possible answer to question 3 is a brake line clamp? Wouldn't this clamp damage the line internals?  I have never seen this in any of the DIY's posted on the net. Perhaps another member can confirm if this is the answer to question 3. 

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Hey guys I am going to replace the o rings and dust boots on my calipers this weekend if all the parts arrive in time, I have done a lot of research on the DIY for removing the pads and calipers however I have some questions regarding the procedure that I can't seem to find a definitive answer on, they are;

 

 

1) Should I remove some brake fluid from the reservoir before starting? Where should the fluid level be before removing the calipers? 

 

2) Should I leave the brake pedal where it is or place something against it pressing it down slightly? 

 

3) When removing the brake line from the caliper I assume some fluid will come out, will this stop at a certain point or continue to pour? Should I tie a small plastic bag around the ends? 

 

4) With the front vibration dampeners & rear spider things on the back of the brake pads, some ppl say leave them off while some put them back on, what do you recommend? and do I need to apply a adhesive to get them back on? 

 

5) Do I need to use brake pad grease when reinstalling the pads? 

 

6) My brakes tend to squeal when coasting to a stop, is there something I can do to the pads while I have them off to stop this? Like applying something to the surface or sanding it with some fine sand paper? 

 

7) After reconnecting everything and before doing the bleed I assume there would be air in between the brake line caliper connection through to the brake pistons, inside the caliper, how do you get this air out or will it just fill up naturally when you bleed?

 

 

Thanks guys I really appreciate your help! :)

 

If you do not cap the brake hard lines when you remove the flex lines & calipers, you will quickly find out why Porsche developed the method of using the diagnostic computer to run the ABS/PSM system while bleeding the system, as the entire contents or the hydraulic system will gravity drain and you will get air into the control network.  You do not need anything elaborate to cap the hard lines, a piece of rubber hose with a tight fitting screw in one end will do the job. 

 

I personally do not like clamping the rubber soft lines, they are already soft enough to reduce the hydraulic pressure in the system.  If you want to do the job right, plan on replacing the rubber flex lines with DOT approved braided stainless lines while you have the car apart.  You see a noticeable change in how your brake pedal feels when these lines no longer pliable rubber.

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Hey guys I am going to replace the o rings and dust boots on my calipers this weekend if all the parts arrive in time, I have done a lot of research on the DIY for removing the pads and calipers however I have some questions regarding the procedure that I can't seem to find a definitive answer on, they are;

 

 

1) Should I remove some brake fluid from the reservoir before starting? Where should the fluid level be before removing the calipers? 

 

2) Should I leave the brake pedal where it is or place something against it pressing it down slightly? 

 

3) When removing the brake line from the caliper I assume some fluid will come out, will this stop at a certain point or continue to pour? Should I tie a small plastic bag around the ends? 

 

4) With the front vibration dampeners & rear spider things on the back of the brake pads, some ppl say leave them off while some put them back on, what do you recommend? and do I need to apply a adhesive to get them back on? 

 

5) Do I need to use brake pad grease when reinstalling the pads? 

 

6) My brakes tend to squeal when coasting to a stop, is there something I can do to the pads while I have them off to stop this? Like applying something to the surface or sanding it with some fine sand paper? 

 

7) After reconnecting everything and before doing the bleed I assume there would be air in between the brake line caliper connection through to the brake pistons, inside the caliper, how do you get this air out or will it just fill up naturally when you bleed?

 

 

Thanks guys I really appreciate your help! :)

 

If you do not cap the brake hard lines when you remove the flex lines & calipers, you will quickly find out why Porsche developed the method of using the diagnostic computer to run the ABS/PSM system while bleeding the system, as the entire contents or the hydraulic system will gravity drain and you will get air into the control network.  You do not need anything elaborate to cap the hard lines, a piece of rubber hose with a tight fitting screw in one end will do the job. 

 

I personally do not like clamping the rubber soft lines, they are already soft enough to reduce the hydraulic pressure in the system.  If you want to do the job right, plan on replacing the rubber flex lines with DOT approved braided stainless lines while you have the car apart.  You see a noticeable change in how your brake pedal feels when these lines no longer pliable rubber.

 

Good advice

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Do I need to remove the flex lines? I was just planning on removing the calipers from them. I might replace them while I am there... I just purchased several different sized rubber plugs to plug the hard line If I do decide to remove them. 

 

So If I remove the flex lines, and install new ones, the brake fluid level will drop slightly as it fills the new flex lines and into the caliper.. so I assume I should ensure the brake reservoir is at the max level before beginning as to not introduce air into the system? 

 

 

Plus could you advise on my other questions please. 

 

Thanks guys :)

Edited by no1joey
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Do I need to remove the flex lines? I was just planning on removing the calipers from them. I might replace them while I am there... I just purchased several different sized rubber plugs to plug the hard line If I do decide to remove them. 

 

So If I remove the flex lines, and install new ones, the brake fluid level will drop slightly as it fills the new flex lines and into the caliper.. so I assume I should ensure the brake reservoir is at the max level before beginning as to not introduce air into the system? 

 

 

Plus could you advise on my other questions please. 

 

Thanks guys :)

 

Leave the fluid level in the reservoir alone.

 

Leave the brake pedal alone.

 

As mentioned, you need to disconnect the flex line at the hard line connection and then cap the hard line to prevent the system gravity draining and getting air into the control network,

 

We replace the vibration dampeners on pad kits that do not come with new ones, we use a dab of silicone brake grease to hold them and reduce the potential for noise.

 

Yes, used a quality brake grease on the lube points noted in the service manual.

 

You can try to sand your rotors, but I would check them for correct thickness and replace if needed.  Noise problems with the brakes on these cars tend to be with the pads rather than the rotors.

 

Any air that gets in while servicing the calipers will come out during a system bleed once the car is assembled.  We use only pressure bleeding, using one of Motives units, which both speeds up the process and makes it a one man proposition.

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Thanks JFP! 

 

Would this do for brake grease or is this for something different? - www.bendix.com.au/content/high-performance-brake-lubricant 

 

And can I re-use the vibration dampeners if using the same pads? 

 

Grease looks good.

 

We reuse the vibration dampeners all the time, as long as they are not corroded or damaged in any way.

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Which brand of braided lines do you recommend?

 

I've seen some brands with stainless steel fittings boast they are better than zinc plated fittings. 

 

Also what's the torque setting for the nuts of these flex lines? Or is it just as tight as it can go? 

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Which brand of braided lines do you recommend?

 

I've seen some brands with stainless steel fittings boast they are better than zinc plated fittings. 

 

Also what's the torque setting for the nuts of these flex lines? Or is it just as tight as it can go? 

 

I am partial to Goodrich, but there are several others that make excellent braided SS lines as well like Crown.  I also prefer all stainless.

 

The flex lines do not really have a torque spec that I am aware of, just "good and tight" is the way to go, as long as there is no leakage.

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Thanks. My brakes should feel amazing after new fluid rubbers and lines. Can't wait! 

 

One final question, the brake grease goes in between the dampers and back of the pads right? where the adhesive is from the dampers? This is ok to put brake lubricant here? 

Edited by no1joey
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Hey guys just wanted to know where exactly the ceramic brake lubricant goes, does it go in between the shims and back of brake pads, on a spot approximately where the caliper pistons will press? 

 

I assume if it does go here placing it over the shims adhesive backing isn't such a big deal since the shims lock into place right? 

Edited by no1joey
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Hey guys just wanted to know where exactly the ceramic brake lubricant goes, does it go in between the shims and back of brake pads, on a spot approximately where the caliper pistons will press? 

 

I assume if it does go here placing it over the shims adhesive backing isn't such a big deal since the shims lock into place right? 

 

We apply the brake grease to the back of the pads before the shim is added, and then around the lip of the piston where it contact the pad/shim.  Don't go nuts applying the grease, a little goes a long way.

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Hey guys just wanted to know where exactly the ceramic brake lubricant goes, does it go in between the shims and back of brake pads, on a spot approximately where the caliper pistons will press? 

 

I assume if it does go here placing it over the shims adhesive backing isn't such a big deal since the shims lock into place right? 

 

We apply the brake grease to the back of the pads before the shim is added, and then around the lip of the piston where it contact the pad/shim.  Don't go nuts applying the grease, a little goes a long way.

 

 

 

Thanks JFP. This brake lubricant is temp resistant to 3000f so I don't think it will run. Also it is meant to be safe on rubber so I don't see it causing any issues with the dust boots, those are around the lip of the pistons right? 

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Hey guys just wanted to know where exactly the ceramic brake lubricant goes, does it go in between the shims and back of brake pads, on a spot approximately where the caliper pistons will press? 

 

I assume if it does go here placing it over the shims adhesive backing isn't such a big deal since the shims lock into place right? 

 

We apply the brake grease to the back of the pads before the shim is added, and then around the lip of the piston where it contact the pad/shim.  Don't go nuts applying the grease, a little goes a long way.

 

 

 

Thanks JFP. This brake lubricant is temp resistant to 3000f so I don't think it will run. Also it is meant to be safe on rubber so I don't see it causing any issues with the dust boots, those are around the lip of the pistons right? 

 

 

If it is a quality product made for use on brakes, no, it should not bother the boots.  We just like to use enough to lubricate, but not so much that it might attract dirt or fall off and get on the rotors.

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