stripped torx bolt on front calipers

[littleD55555]

i took the front tires off to see that it looked as if the car had never moved. There are 4 bolts that hold the calipers together and the would not budge and if they did it just spun the entire bolt not losening off the nut so i got a torx screw driver to hold the front while i turned the nut on the back. It did work very well it was on there so tight it just stripped the torx's streads

my shop teacher sugested tacking a nut to the top of the torx bolt and using it to hold it while it is lossened from the back because the torx threads are shout
Any Suggestions

[opel kid]

Do as shop teacher said, or drill it out with a left handed drill.
but welding a nut to it works fine..

[oldopelguy]

There's really no good reason to take those 4 bolts out unless you're rebuilding the caliper, and since the seals in the caliper you need to replace if you do get it apart are very hard to find you might not want to give that a shot.

If you're trying to get the caliper off, there's two bolts on the back side you take out then it comes off then end of the rotor as one complete unit.

[namba209]

Well, first off, the bolts that hold the caliper on are not Torx bolts, they are triple square internal wrenching bolts and require a special tool to insert in the head of the bolt. The caliper bolts and nuts are torqued to 72 foot pounds. I would suggest using a liberal amount of anti-rust/penetrating oil on the exposed threads to assist in removing them.

[kwilford]

And second off DON'T split the calipers

There is a special square shouldered O-ring that is virtually unobtainable that seal the two halves, and since your shop teacher doesn't know squat about Opels, you need to read about how to rebuild Opel calipers BEFORE you start destroying them by taking them apart.

[littleD55555]

I need to turn the rotors on the laith and possibly replace the break pads nothing has been done to them in a long time but i guess thats why a torx striped the bolt.
Where can you get one of those tools? or Do you have to take the bolts of to get the rotor out?
I was also wondering what the min. rotor thickness is? teacher wont let it out of the shop if it is to worn down, but he can't find the specs in his books.
What else sould i do to breaks that have not been serviced in a long time?
kinda new at this thanks for your help

[namba209]

IIRC there are 4 sizes of the triple square bits needed on Opels. The two that I have and used them to remove the discs from the front spindles are K-D tool numbers 2306 and 2308. The minimum thickness for the rotors, according to my Haynes manual, is 0.394' (10.001 mm). HTH.

[opelwasp]

OK are you talking about the calipers or the hub/rotor. The hub/rotor needs the 12 point tool to get them out but the caliper does not(6 points, I just went out and verified).

[kwilford]

Originally Posted by opelwasp OK are you talking about the calipers or the hub/rotor. The hub/rotor needs the 12 point tool to get them out but the caliper does not(6 points, I just went out and verified).

Opelwasp is correct, two normal hex bolts are removed to disconnect the caliper. First, spread the pads a bit to relieve their grip on the rotor. If the caliper is seized, this can be the hardest part of R&R'ing disk brakes. Then remove the two bolts that attach the caliper to the steering spindle (around the back of the caliper) and hang the caliper with a piece of wire NOT WITH THE FLEX HOSE. Although replacing the flex hose is what you almost certainly need to do as well, which is another story. Then remove the bearing dust cap, remove the cotter pin, undo the axle nut and slide the entire hub with the rotor out off the spindle axle. Most shops can turn the rotors while still on the hubs, If not, or if you need to replace the rotors, then there are four triple-square headed bolts that hold the rotor to the hub. NOT A TORX HEAD!!!! If your Shop Teacher tells you to use a Torx headed tool, immediately drop out of his class and take Home Economics as you will learn more useful things there.

You will also need to replace the dust seal at the back of the hub BEFORE you re-install it.

Seriously, if you have an Opel Factory Service Manual, get it out and read the sections on brakes. If not, get one now and read it BEFORE you mess up that car anymore.

[namba209]

Keith and Chris, you're both right. I was looking in my Haynes Manual at the exploded view of the caliper and it does show the triple square bolts holding the two halves of the caliper together. Definitly do not want to remove those bolts. The ones that hold the caliper on are the two on the inside of the spindle. Thanx to you both for getting that straight. But he does need the special tool to get the rotor off the hub.

[hrcollinsjr]

Look on the back of the calipers for 19mm bolt heads, remove these two bolts, spread the brakes pads a little and the caliper should slide off. A 10mm triple square bit is required IIRC to remove the rotor from the hub. The triple square bits don't work very well on the bolts holding the calipers together. OpelSpyder located the correct bit for me but I forgot what it is called but it's not a standard torx or triple square bit.

Harold

[opelspyder]

The bit is called a torx plus, and usually carried by tool dealers such as Mac and Snap On. I would suggest leaving those bolts alone!!!!! Or you in more likelyhood-will be buying some more
Keith

[Sparky73]

Those "torx plus" tools can be purchased from NAPA as well. It's been a few years since I bought mine, but I think I just asked about them, and I had to wait a couple days for them to come in. Could be purchased as a set, or in singles.

[opelwasp]

I just got a new set at Kragen. They are about 8 inches long with socket adapters too, very nice.

[kwilford]

Not triple square

Originally Posted by opelspyder The bit is called a torx plus, and usually carried by tool dealers such as Mac and Snap On. I would suggest leaving those bolts alone!!!!! Or you in more likelihood-will be buying some more Keith

Keioth, I presume that you are referring to the bolts that hold the calipers together, which in my experience are a Torx head from the Ate (Alfred Teves Enterprises I believe) factory, about 35 mm (or at least my T-30 is too small, and my T-40 too big). I have also seen calipers that have been rebuilt by a professional shop that replaced the Torx headed bolts with standard (albeit high strength) hex-headed bolts. Those are the bolts that should NOT be loosened, nor is there any reason to, as the sealing ring between the calipers are not available, and they can be readily rebuilt without splitting them.
The four bolts that hold the rotor to the hub are indeed 10 mm triple square, and can only be accessed from the back of the rotor when the hub and rotor have been removed. "littleD55555", do NOT attempt to use a Torx tool on these.\
HTH

[littleD55555]

Cool thanks for your help guys, Ill have to wait till monday to try it out, my cars at the schools shop so i cant do anything till then. I put some pics of the car in my members album.

[Bill Hoffmann]

Originally Posted by littleD55555 I need to turn the rotors on the laith I was also wondering what the min. rotor thickness is? teacher wont let it out of the shop if it is to worn down, but he can't find the specs in his books.

Per the 1973 Opel GT FSM, the thickness for new discs is 0.430", and the minimum thickness is 0.394". My prediction is that you will be soon shopping for new discs, since that allows for only 0.018" per side of wear, grooves, and/or rust. If it were my car, and I could clean up the rust across the swept area while staying above the minimum thickness, I wouldn't worry about a few grooves. I'm sure your shop teacher and some here will disagree, it's just my opinion.

Bill

[namba209]

Actually Bill, I will not disagree with you on having grooves in the rotors or drums, as long as they meet or exceed the minimum requirements. All those little valleys and peaks give you more swept area. Granted not a lot more, but some.

[littleD55555]

they are pretty rusted thats why my teacher said to turn them on the laith, but if i can get away with wire brushing or something, thats cool. About how much are new disc? and I have about 4 feet of steel breaded break line that i got for free ,will it give me much improvment?

[namba209]

You can try the wire wheel on your rotors, then measure them to be sure they're thicker than .394". 4 feet of steel braided brake hose is cool, as long as you can cut it to the correct length and install the correct fittings on it. I would measure the existing hoses, at each front brake and the one that hooks up the the differential to be sure you have enuff. Don't expect any improvement over the standard hoses other than looks and possibly longevity. After all hydraulics is hydraulics. One thing about steel braided hoses, they have a teflon inner tube and if it gets kinked, it will fail.

[jvandyke]

Originally Posted by namba209 Don't expect any improvement over the standard hoses other than looks and possibly longevity. After all hydraulics is hydraulics. One thing about steel braided hoses, they have a teflon inner tube and if it gets kinked, it will fail.

Back in my bik'n days, steel lines were nice as they didn't flex, therefore the force goes straight to the caliper instead of the rubber hose flexing a bit first. On a car with 90% steel lines and only three short pieces of rubber, probably wouldn't notice a difference?