Need Advice: steel plates in brake calipers

[dick911]

Hello,

Since the steel plates in my 964 brake calipers moved up by corrosion I want to replace them. They are bolted in the caliper body and those tiny bolts are a P.I.T.A. to remove .
I think the bolts were put in with Locktite (or something like that).

Does anyone have any tips/trics how to remove these bolts in a safe and easy way ?? I do not want to break one in the caliper....
I was thinking of heating up but I'm afraid that the heat will damage the calipers.

Thanks in advance.

Dick911

[Bill Verburg]

They are Lok tited in, I've had good luck w/ a heat gun

[dick911]

Mmmm, I have a heat gun but I'm afraid to damage surrounding rubbers at the pistons....

Thanks Bill.

Anyone else any advice on this ??

[fleetline51]

dick911:

I don't know what type of heat gun you have but the Home Depot stores in the U.S. sell varied fittings that clip onto the nozzle of the gun and allow the heat to be concentrated to a small area instead of allowing heat generation to widely blow all
over.

There are also "micro-torches" that have high -temp,pin-point flames that are capable of soldering copper pipe for plumbing applications...they are small,powerful and inexpensive...most are disposable after fuel runs out,some have refill capabilities.

The micro-torch would be my first choice,after which a couple of well delivered
accurate whacks with a small mechanics hammer and a blunt head punch would hopefully free up those stubborn bolts.

If you use(d) penetrating oil on the bolts and decide on the micro-torch route, be
careful of "flame-ups." Hope this helps.

Best Regards, Fleetline51 (Tony)

[dick911]

Ok thanks ! Good idea.
I am off to the store for a micro torch

Dick911

[fleetline51]

dick911:

Please let us know how it turns out...it may be of help to us all!

Best Regards, fleetline51 (Tony )

[dick911]

Update !!

Bought a micro torch (great thing..) and heated the screw(s) just on the spot...
nothing happened.
They're still in place.

When the screw(s) turn red from the heat, will that be hot enough to break down the Loctite ?

Any ideas ?

Thanks in advance,

Dick911

[chfs911]

My bolts were T27 and all bar one came out easily. You need to shock the bolt to break the loctite. Chap with small hammer.

I have heard spot welding the torx(some may be allan key) works well but you need the tools for this.

I replaced all the bolts with new ones and did the seals at the same time. Plates can be reused.

I resorted to contracting out the difficult one to a shop with the right equipment and experience. They used ultrasound to remove a partially drilled bleed valve.

[dick911]

UPDATE

Finally got all out !!

How ?

The 'chisel method' worked best. Did not used any heat because I could not get the screw cherry red with the butane torch.

I made a 'cross' in the head of the allen screw with a Dremel. Then I used a hardened chisel (Stahlwille... yes, German..) to tap sideways into the cuts I made in the head of the screw.
I used a small / light hammer instead of a big heavy one.

Took about 10-15 minutes 'easy tapping' per screw and finally they went loose.

Thank you all for the tips & trics.

Regards,

Dick911

[DCinVA]

I am reviving this old thread as I needed to clean my spring plates due to brake squealing (driving me crazy), and this thread helped me to address the problem of those pesky bolts that hold the spring plates on.

I found the best method of removing the spring plates was to clean out the allen bolt hole really well with a pick, and then soak with PB Blaster for a while. Then I put a small tip on my oxy acetylene torch ( I am sure a micro torch would work) and got a cup of ice cubes to try to keep the caliper cool. Apply very focused heat to the head of the bolt until it just starts to turn red, then quick cool with a stream of PB Blaster. Insert your allen and and loosen the bolt 1/8 of a turn, that's about all you get before you have to reposition the allen. Cool the bolt and the caliper with an ice cube, I rubbed the ice cube on top of the caliper to remove as much heat as possible, then reinsert the allen wrench and finish taking out the screw. Then move on to the next screw.
The objective is to try to keep the caliper as cool as possible during the process.
If you do any tapping with a hammer and/or a punch be careful not to damage the allen hole in the bolt. Your allen wrench needs to be firmly and deeply seated in the hole in order to remove them.

While I am in there I am going to rebuild the calipers with the kits offered by Porsche. Unfortunately the kits are sold for a single piston, so you need 4 kits for each caliper. The kits include a new piston, which I do not need, and are pretty pricey.

To remove the pistons put a block of wood where the break pads go, then use compressed air to move the pistons out. Your objective is to move all the pistons out with the air but not pop them completely out of their bores. Select a block of wood thick enough so that it stops the pistons from coming completely out, that way you can push all 4 pistons out before removing them the rest of the way by hand. Some folks use a grease gun to do this rather than compressed air, and frankly, that is probably a safer way to do it. You would need to rig up some sort of a fitting that would screw in where the brake line attaches, but the rest of the process would remain the same.

Lastly, if anyone has a source of a seals only caliper kit for a 964, I would love to hear from you.

[porterdog]

Caliper, Piston, Repair, dust, boot, scraper, ring, Brembo

[AOW162435]

Originally Posted by DCinVA

I am reviving this old thread as I needed to clean my spring plates due to brake squealing (driving me crazy), and this thread helped me to address the problem of those pesky bolts that hold the spring plates on.

I found the best method of removing the spring plates was to clean out the allen bolt hole really well with a pick, and then soak with PB Blaster for a while. Then I put a small tip on my oxy acetylene torch ( I am sure a micro torch would work) and got a cup of ice cubes to try to keep the caliper cool. Apply very focused heat to the head of the bolt until it just starts to turn red, then quick cool with a stream of PB Blaster. Insert your allen and and loosen the bolt 1/8 of a turn, that's about all you get before you have to reposition the allen. Cool the bolt and the caliper with an ice cube, I rubbed the ice cube on top of the caliper to remove as much heat as possible, then reinsert the allen wrench and finish taking out the screw. Then move on to the next screw.
The objective is to try to keep the caliper as cool as possible during the process.
If you do any tapping with a hammer and/or a punch be careful not to damage the allen hole in the bolt. Your allen wrench needs to be firmly and deeply seated in the hole in order to remove them.

While I am in there I am going to rebuild the calipers with the kits offered by Porsche. Unfortunately the kits are sold for a single piston, so you need 4 kits for each caliper. The kits include a new piston, which I do not need, and are pretty pricey.

To remove the pistons put a block of wood where the break pads go, then use compressed air to move the pistons out. Your objective is to move all the pistons out with the air but not pop them completely out of their bores. Select a block of wood thick enough so that it stops the pistons from coming completely out, that way you can push all 4 pistons out before removing them the rest of the way by hand. Some folks use a grease gun to do this rather than compressed air, and frankly, that is probably a safer way to do it. You would need to rig up some sort of a fitting that would screw in where the brake line attaches, but the rest of the process would remain the same.

Lastly, if anyone has a source of a seals only caliper kit for a 964, I would love to hear from you.

I am slowly rebuilding a complete set of 993 calipers that have the worst 'plate lift' I've ever seen. The small screws are in such bad shape that the only way to remove them is using the heat & chisel method.
The plates are stainless steel and can be straightened if tweaked.



Andreas

[DCinVA]

Thanks for the link Porterdog! I ordered some kits from a dealer in Mill Valley Ca, that has very good pricing.

Andreas, it sounds like you will need to find a source for replacement screws!

[AOW162435]

Originally Posted by DCinVA

Andreas, it sounds like you will need to find a source for replacement screws!

I have the correct screws on hand.



Andreas