Stripped banjo bolt…helicoil?
 

Finally got around to adding fluid to the system & noticed a steady drip from the driver’s front caliper. I tried tightening the bolt & it helped a bit but didn’t stop it completely. I loosened & tightened it again to no avail. Tried tightening it a bit more when righty tighty became lefty loosey. 😳 All parts are new with Wilwood D154 calipers. Would it be worth it to try a helicoil or just replace it?

Re: Stripped banjo bolt…helicoil?
 

for brakes I NEVER rely on a helicoil. helicoil on a caliper would possibly allow shavings into the caliper. sad to toss a new part, but if it were me I would replace it. if doing a thread repair I would dissassemble the caliper, clean it, and drill a larger size hole so threads for a large "bolt" could be tapped into the casting. then install the bolt and drill it for the thread you need for the banjo. I suppose a bolt could be predrilled and threaded and then screwed into the newly cut threads in the caliper. use a thread locker and possibly stake the bolt in place so it never tried to unthread itself. then finish the top end of the bolt where the banjo seal will be so as to be a fresh clean flat surface for the copper washer to seal on. clean the casting inside and out also and then reassemble the caliper. the new copper washers for banjo bolts usually have small ridges machined into them to have a "crush zone" when tightened.
there should have been a new copper washer on each side of the banjo fitting. were they there? if so, check the fitting and the casting to ensure there was no flaw. the copper washer is supposed to crush a little to compensate for slight flaws, thats what the ridges on the copper washer are for, to assist in the crushing and sealing.
new parts could have a flaw in the casting, sealing surface or the threaded part. before you install the new part, or before you repair the old part, check to ensure the bolt hole is perpendicular to the sealing surface for the copper washer and make sure the threads are complete all the way around the drilled hole and also full depth all the way around. try the bolt to ensure it will fit well in a new nut of the same thread. also check it for signs of being stretched since you did torque it down quite a bit by the sounds of it. they tend to stretch where the hole is drilled through the side and, since they are hollow, they tend to stretch when overtorqued or can also twist from the torque applied. it's brakes, best not rely on something that isn't up to par. there are other places to save money.

Re: Stripped banjo bolt…helicoil?
 

You should get a new caliper, probably a new banjo too

Re: Stripped banjo bolt…helicoil?
 

Yeah, you’re both right, just ordered a new one but man this sucks!

Re: Stripped banjo bolt…helicoil?
 

use a torque wrench next time. if it leaks then there is another problem that tightening more isn't likely to fix. check the banjo fitting for damage or irregularities before installing, replace the copper washers and the bolt

Re: Stripped banjo bolt…helicoil?
 

Will do, thanks!

Re: Stripped banjo bolt…helicoil?
 

I've done more brake jobs than I want to count when I was doing it for a living and never saw one of those leak unless someone did something wrong.

Usually it is by not putting in one of the copper washers, putting them both on one side or by reusing one that had been damaged. It normally doesn't take more than a good tug on a box end wrench to have them tight enough.

Re: Stripped banjo bolt…helicoil?
 

1st time for everything I suppose. Not my 1st rodeo, but it was installed correctly, new banjo bolts and crush washers were used. I’m leaning towards what dsraven mentioned thinking it was a bad casting as fluid seemed to be coming from inside of the caliper as well. If I hadn’t had them so long I’d send it back but I purchased them last year.

Re: Stripped banjo bolt…helicoil?
 

you could try for a warranty replacement, might be worth a call.

https://www.wilwood.com/BrakeKits/Br...emno=140-12567

Re: Stripped banjo bolt…helicoil?
 

tech support line and phone etc at the bottom of the page

Re: Stripped banjo bolt…helicoil?
 

I was under impressed with the last new crush washers I used, they took a lot more torque than I am used to to not weep, I had the tires off three time to get it.
maybe there are some quality issues with the washer supply

Re: Stripped banjo bolt…helicoil?
 

I've also had a few issues with the new crush washers and it seems they are harder material than they used to be. copper is big bucks so you gotta wonder.

Re: Stripped banjo bolt…helicoil?
 

I'd have to believe that you may have hit on the real issue. Suppliers cutting corners . No caliper manufacture would make their own crush washers, they buy them from suppliers just as they do the banjo bolts.

Having to contend with less than stellar parts wasn't an issue when I was working on them every day as long as you bought the "good" parts.

Throw in the simple fact that too many bean counters in companies push to "get it cheaper" and the base castings that they machine their calipers from could be a bit suspect or maybe there was a bad batch.


I don't see why you can't helicoil the threads though, you will have to have a bottoming tap to cut the threads for the helicoil as a tapered tap isn't going to get threads down far enough. The copper washers are the actual seal. I'd hunt down some actual soft copper washers though.

Re: Stripped banjo bolt…helicoil?
 

back in the day you could buy a copper washer with small ribs on the sealing face. now they are all flat copper washers. i guess the ribbed part is on the caliper and the fitting surfaces but not usually on the head of the banjo bolt sealing surface. anyway, try to get the best parts you can for doing the brakes because brakes are the thing that can save your skin but are the thing most people just take for granted and want to spend the least on repairing properly.

Re: Stripped banjo bolt…helicoil?
 

Yeah, tried that...no luck.

Re: Stripped banjo bolt…helicoil?
 

I would rather have a heli-coiled hole than a regular threaded hole in aluminum. At least you could put the proper torque on those chinesium sealing washers.

Re: Stripped banjo bolt…helicoil?
 

really?! A helicoil is essentially a coil of wire in the right thread pitch that jambs into an oversized hole when you thread the original fastener in.
Each time you tighten it is gets bigger & looser.

A threaded insert may give you longer lasting, tougher threads than an aluminum part on it's own, but a helicoil is not a threaded insert.

Re: Stripped banjo bolt…helicoil?
 

Helicoils are much stronger than the original threads because they have a larger bearing surface in the original material. There are many test out there that prove this. Watch this video
https://youtu.be/jknMrFOGMOQ

Re: Stripped banjo bolt…helicoil?
 

the simple truth is a helicoil may work but your going to rely on this caliper so don't short change your safety and replace it!

Re: Stripped banjo bolt…helicoil?
 

helicoils have their place but to me a helicoil won't go in my brake system.
thats just my opinion so not worth much. haha.
spend the bucks and get a new part but check it over closely for flaws before you install it or put it on a shelf for install when the time comes.

Re: Stripped banjo bolt…helicoil?
 

The precision and reliability of the HELICOIL® wire thread inserts have been well proven by the demands of the aerospace and defence industries over the decades and are used extensively in some of the world’s most popular and modern airliners. The product portfolio includes a wide variety of globally referenced aerospace and defence specification wire thread inserts specified and used by major manufacturers around the world.

The list of certified approvals for HELICOIL is comprehensive and includes such standards as AGS3600, AGS370, AGS4677, EN2942, EN2944, EN3542, MA3281 , MA332. A typical example of the use of HELICOIL would be in the design of aircraft seats made of high-strength aluminium with an anodised surface finish.

From a practical viewpoint, installing a HELICOIL 6-32UNCX x 1.5d Screw-Lock type permits frequent assembly, disassembly and re-assembly without the risk of thread wear while also adding an in-built thread locking feature for added joint security. Parts are manufactured in accordance with LN-9499

Re: Stripped banjo bolt…helicoil?
 

Finally got around to replacing the caliper & was shocked initially to find that the new one leaked as well. But after a little trouble shooting I discovered that the leak was coming from the two piece braided line I was using. I'd forgot to fully tighten during assembly. Lesson learned, but it was costly.

Re: Stripped banjo bolt…helicoil?
 

If you run into a situation like this again you might try a talcum powder based tracing powder. I use the stuff that comes in a spray can. You can also sprinkle baby powder or foot powder on the leak but the spray powder is much easier. Some foot powders come in a spray can. Search for leak tracing powder and using powder to trace leaks on the web. You just clean and blow off the area and apply the talc and the leak will show up as a clear area surrounded by dry talc. make sure the area is clean and dry before applying the talc.

Re: Stripped banjo bolt…helicoil?
 

Thanks for the tip!