Squealing Boxster Brake Upgrade

[Bob Kontak]

I installed the Boxster brake upgrade kit on my 81SC several years back. In reading through several threads on this upgrade, I found that I had the brakes on upside down relative to the piston size. I have the larger piston on top.

The car is street use only and they squeal with light application. After a hard street run with heavy braking they will be quiet for quite a few stops but then back to the noise.

Recently, I purchased the inserts from Porsche that slide into the pistons and the squeal remains. I have re-installed the original brakes for the moment as the noise is irritating.

Having read all the threads I see that I really don't need them for my driving but they do look quite cool through the fuchs with the cross-drilled rotors and bigger calipers.

My questions (finally)... Would the incorrect mounting of the calipers create the squealing noise? Could the fix be simply to change out the plumbing and swap sides? Are there any other "must dos" to properly install them? I am aware of the stretch bolts.

Thanks

[Bob Kontak]

All,

From the lack of response, I believer the answer is pretty clear. Swap the calipers from side to side and find out if they don't squeal. Also, additional searches and discussions have indicated that my calipers were set up to promote squealing.

I do need some help. I need to swap the two bleeders to the end where the caliper crossover brake line is and vice versa. The crossover lines are in real tight. Is it ok to use heat to loosen them? Perhaps there is a form of thread lock on them? I have rounded off one of the line fastener hex heads and don't want to proceed until I get some advice.

Thanks,

Bob

[Bill Verburg]

Originally Posted by Bob Kontak

I installed the Boxster brake upgrade kit on my 81SC several years back. In reading through several threads on this upgrade, I found that I had the brakes on upside down relative to the piston size. I have the larger piston on top.

The car is street use only and they squeal with light application. After a hard street run with heavy braking they will be quiet for quite a few stops but then back to the noise.

Recently, I purchased the inserts from Porsche that slide into the pistons and the squeal remains. I have re-installed the original brakes for the moment as the noise is irritating.

Having read all the threads I see that I really don't need them for my driving but they do look quite cool through the fuchs with the cross-drilled rotors and bigger calipers.

My questions (finally)... Would the incorrect mounting of the calipers create the squealing noise? Could the fix be simply to change out the plumbing and swap sides? Are there any other "must dos" to properly install them? I am aware of the stretch bolts.

Thanks

yes, it can make a difference but there are other causes too.

The calipers are mounted correctly(or in this case as correctly as is possible) when the small piston is in the leading position, ie sees a given point on the rotor first and the bleeds are on top.

Squeel can also come from;
road mung, solution wash them regularly w/ a hose

improper pads solution use street pads they are much softer and are designed primarily not to squeel

not using the oem spyders solution use them

[Jeff Alton]

The Boxster brake conversion (hesititate to say upgrade) is well documented here to squeal. This is a very common problem for those that make this conversion.

Cheers

[tonythetarga]

Contact TreCup (Dave) or search his name for the right pad choice. Apparently, this set up will squeel with just about every pad except one and I don't remember which one. I run this set up but strictly on track and they only squeel until they heat up and then it's good.

[Jeff Alton]

The pad is the Porterfield R4S.

Cheers

[Zeke]

Does chamfering the leading edge of the pads help in this application as it does on regular brakes?

[Jeff Alton]

Pretty much nothing helps with these

Cheers

[DinFtown]

Originally Posted by Jeff Alton

The Boxster brake conversion (hesititate to say upgrade) is well documented here to squeal. This is a very common problem for those that make this conversion.

Cheers

Amen to that... anyone calling this a upgrade is just delusional....

[jester911]

No offense but why would someone "upgrade" Porsche brakes for the street?
Rhetorical question I know.

[Bob Kontak]

Originally Posted by Bill Verburg

....The calipers are mounted correctly(or in this case as correctly as is possible) when the small piston is in the leading position, ie sees a given point on the rotor first and the bleeds are on top.

not using the oem spyders solution use them

Old post but finally took my Boxster brake "upgrade" out of the box and re-installed them. Flipped them over so the small piston is in front and with the oem spyder units installed. Now have a pretty nice set of brakes that feel better than stock and squeal a wee-tiny bit when cold at some street stops but not a bother (obnoxious) like before with the big piston leading the way.

Thanks!

[Rodsrsr]

I have the same conversion and also installed them incorrectly the first time. After re-orienting the calipers and putting a small amount of anit seize on the back side of the pad, I have absolutely zero noise. Its been close to a year now and still all's good.