I just stripped the bolt hole in the worst possible place, the caliper bolts. It's a 2003 clk500, brembo style brakes. It's in the rear, dual pistons. What can I go about to fix this? Thanks in advance.
Stripped bolt hole
- Thread starter PhuongFU
- Start date
- Status
Pictures???
Originally Posted by PhuongFU
I just stripped the bolt hole in the worst possible place.
There are much worse places in the engine bay to strip a bolt hole. Possibly you could just use a longer bolt with a nut on the other side, or just replace the part that you stripped out. Hard to know without more details.
I just stripped the bolt hole in the worst possible place.
There are much worse places in the engine bay to strip a bolt hole. Possibly you could just use a longer bolt with a nut on the other side, or just replace the part that you stripped out. Hard to know without more details.
This car AFAIK does not use a caliper bracket the threads are in the rear spindle/knuckle which cost about $600+. You need to use a Time Sert to repair the threads, do not use a helicoil as its a through hole.
You need the correct thread pitch and bolt size then order a set with the correct depth inserts. Its an easy enough job for a skilled mechanic but may prove a bit daunting for a DIY especially if you never did one, you only have one shot at this as a Big Sert is too big if you make a pigs ear of it.
The Time Sert set for this is probably $100 so its well worth doing.
![[Linked Image]](https://www.bobistheoilguy.com/forums/attachments/usergals/2019/08/full-14074-35112-500_clk_spindle.jpg "[Linked Image]")
You need the correct thread pitch and bolt size then order a set with the correct depth inserts. Its an easy enough job for a skilled mechanic but may prove a bit daunting for a DIY especially if you never did one, you only have one shot at this as a Big Sert is too big if you make a pigs ear of it.
The Time Sert set for this is probably $100 so its well worth doing.
Last edited:
Easy fix with a time sert.
Why would a Helicoil not work ? They have different styles- in fact I think a through-hole is the default style.
The coil tends to move down in the hole as the bolt is installed. If it is a through hole it can come out the other side. When the hole is deep enough it can be avoided by not tapping all the way through, but then you have to use a shorter coil which is not as strong.
Originally Posted by rubberchicken
Why would a Helicoil not work ?
Might, but it's old tech and better options available.
Why would a Helicoil not work ?
Might, but it's old tech and better options available.
Originally Posted by rubberchicken
Why would a Helicoil not work ?
The standard coil type thread repair is not nearly as strong as the Timesert. I would never consider it for safety related items like a brake caliper.
Why would a Helicoil not work ?
The standard coil type thread repair is not nearly as strong as the Timesert. I would never consider it for safety related items like a brake caliper.
Sorry guys I don't have any picture. It's a through hole. So helicoil no good for through holes? The longer bolt with a nut on the end sounds like a great plan. I'll take a look at it tomorrow. Should be enough room.
As far as changing the hole bracket assembly. That would be expensive unless I find a used one at a junkyard. Being a Mercedes clk500, I might not find one so quickly, I'll definitely take a look at the Timesert. Never heard of it.
As far as changing the hole bracket assembly. That would be expensive unless I find a used one at a junkyard. Being a Mercedes clk500, I might not find one so quickly, I'll definitely take a look at the Timesert. Never heard of it.
What if I use a helicoil coil with some threadlock so it doesn't move?
A standard helicoil is not the correct product for this repair.
I heard that.... I just watched some videos of the Timesert. The guy made it look so easy because he had it on the bench. I want to do it while it's on the car because so many parts will have to be removed for the hub to come off. Everything is connected to that hub. I really hope there will be room for me to place a nut on an extended bolt when I look at it tomorrow.
If you go that route make sure you use a 10.9 bolt with a hardened nut and washers with blue loctite. If you cannot use a full width nut forget it, do not use a jam nut because they are thinner, they are not meant to be the primary nut.
A small angle drill may be of help if clearance is an issue.
I personally would not even consider repairing it like that, with the stripped threads partially grabbing the bolt proper torque is almost impossible and if it begins to move (and it could given the amount of heat and vibrations created during braking especially during ABS engagement) the hole in the tab may get buggered up worst than it is now possibly making a proper repair difficult or impossible.
Brakes are nothing to be taken lightly and shoddily repaired.
A small angle drill may be of help if clearance is an issue.
I personally would not even consider repairing it like that, with the stripped threads partially grabbing the bolt proper torque is almost impossible and if it begins to move (and it could given the amount of heat and vibrations created during braking especially during ABS engagement) the hole in the tab may get buggered up worst than it is now possibly making a proper repair difficult or impossible.
Brakes are nothing to be taken lightly and shoddily repaired.
Originally Posted by PhuongFU
I heard that.... I just watched some videos of the Timesert. The guy made it look so easy because he had it on the bench. I want to do it while it's on the car because so many parts will have to be removed for the hub to come off. Everything is connected to that hub. I really hope there will be room for me to place a nut on an extended bolt when I look at it tomorrow.
On the bench/drill press is the proper technique.
Least hassle and highest likelihood of success.
Time well spent to take it apart and do it right.
If you do it on the car, you'll bugger it up, swear A LOT and still get it wrong.
Then you'll take it apart and do it the right way.
Ask me how I know....
I heard that.... I just watched some videos of the Timesert. The guy made it look so easy because he had it on the bench. I want to do it while it's on the car because so many parts will have to be removed for the hub to come off. Everything is connected to that hub. I really hope there will be room for me to place a nut on an extended bolt when I look at it tomorrow.
On the bench/drill press is the proper technique.
Least hassle and highest likelihood of success.
Time well spent to take it apart and do it right.
If you do it on the car, you'll bugger it up, swear A LOT and still get it wrong.
Then you'll take it apart and do it the right way.
Ask me how I know....
I was able to fix it. I decided to go the bolt and nut route because I am not experienced with thread repair, nor do I have a bench. It was a very tedious job. Several trips to the store to find the correct bolt length. There's only about 1cm of space between the outer end of the bracket hole, and the brake rotor. I actually had to cut away about 5 inches of the metal brake shield to create room for the nut and for me to be able to turn a wrench, using some $15 shears. Even had to remove part of the parking brake shoe. Took a lot of work just for that. I couldn't even fit a locking nut back there. My machinist grinded down a hardened locking nut for me, it was a gamble since we're grinding down a nut, but he assured me that it is much stronger than a jam nut, since it still had normal thickness, just a little flatter. The good thing was, there was still a small bit of thread left inside the hole, towards the outer end, where the stock bolt couldn't reach. So I added a generous amount of blue thread lock on the bolt and the nut, spun the bolt into the caliper/bracket and into the nut. Had to hold the nut in-place with some needle nose pliers. I tighten the bolt first with about 25lb/f, then tighten the nut with 25 lb/f, then I twisted the wrench and ratchet together at the same time, about 80 lb/f. Seems like i should be in the clear hopefully.
I wanna thank all you fellas for the help. It was much appreciated. You guys are some of the most knowledgeable guys on the net.
I wanna thank all you fellas for the help. It was much appreciated. You guys are some of the most knowledgeable guys on the net.
Last edited:
I am curious how you stripped it in the first place ? And are you going to strip it again ?
I will stick with Ford or GM . The salvage yards are full of parts for them .
I will stick with Ford or GM . The salvage yards are full of parts for them .
- Status
