While sorting out the rear calipers on the Furby, the one side seems fine, no leaks, brake comes on and off easily. The other might need a rebuild. Swapped on another caliper only the finish off stripping the internal thread.

 

Anyone out there helicoiled their rear calipers? If so what size kit do I want?

 

Thanks all and Seasons Greetings!

11 hours ago, DoctorBoostaLot said:

helicoiled their rear calipers

The banjo nut that supplies brake fluid or the carrier for caliper?

If former, I would buy as new caliper.

 

If latter, remind me, does it go into rear axle or bolt on hub? Are threads removed. If not try a chaser.

I always spray on penetrating fluid and go for a cuppa, but even after that treatment the rear carrier bolts were seized. A breaker bar 3/8" twisted an S2 steel laser hex bit before it removed rear carrier bolt. Luckily no thread damage.

Yeah the banjo fluid bolt, bloomin things.

Regarding the cap headed carrier bolts I replaced those the last time around and now I own an A4, I ran into the same problem there too!

 

I'd like to the save the caliper if possible, anyone else?

On 20/12/2022 at 03:02, DoctorBoostaLot said:

save the caliper

If the threads have pulled out you can't cut new threads as you can't use a larger banjo nut due to fixed brake line ending. 

Helicoil requires you cut out threads and glue in new threads. Might work. I looked into this but never used. You are unlikely to remove banjo nut again unless you change brake line or the caliper. 

Worth a shot, but I'd check your brake lines are holding pressure.

 

I think the kit is £20 plus and a new rear caliper £70 plus, maybe cheaper. Depends whether you want to play Russian roulette every time you brake. I'd buy a new caliper if it was my car.

Banjo bolt thread is not a standard ISO metric thread so unless a special Helicoil kit has been made for the job it's unlikely you will find one.

 

If you find one then a helicoiled repair will be fine, stronger than the original & shouldn't leak because the banjo bolt brass washer is a larger diameter but it would effectively remove part of its sealing area, I think for that reason and the consequences of the job not being done correctly that nobody will have marketted a repair kit like they do for the caliper slide bolts, I could be wrong.

On 25/12/2022 at 21:23, bmbmdmb said:

Depends whether you want to play Russian roulette every time you brake.

Yeah, I left the original one on the car and gave up on the one with the damaged threads. It really didn't take much to damage the threads either which is a bit worrying. I'm certainly not heavy handed like most spanner monkeys I know. I'll have to keep my eyes open for a spare with decent threads to refurb for the future. Seems to be holding pressure everywhere at the moment, I think I just have some ABS pump purging to do and another bleed.

Buy unpainted and spray yourself.

1. Zinc primer 2. Grey primer optional 3. Colour spray 4. Lacquer.

 

Tip - I mount the new caliper in place on the carrier with the old one still connected to brake line but supported by bungee or zip tie. This way you are only disconnecting the brake line for less than a min.

 

If you brim the brake fluid reservoir to overflowing, then place plastic food bag food wrap over brake reservoir then screw cap back you will not lose a drop of brake fluid when banjo removed from caliper. It creates a vacuum. One piece of thin polythene (thin) you don't want to cross thread reservoir cap.

 

Use new copper or aluminium washer on banjo. Don't spray rattle can paint over where washer goes for banjo, even a lip of paint will cause you a leak. The brake fluid dissolves the paint under it then months later the banjo bolt washer leaks! Even with the banjo tight it will leak.

 

Hope this helps.

 

Abs module bleed (you got obd plug in tool? You will need it btw)

Yep all solid advice!

 

I did exactly that you know on the one with dodgy threads, quick swap, me, "I won't lose much fluid, I'll be quick." and used a rubber glove under the cap. Seeped, nipped it, seeped again and nipped it.

Damn thing wouldn't seal, kept going and still managed to about lose all the fluid and then finally stripped it.

 

I've got VCDS lite (and cable) on a laptop and once all the other jobs are done I shall see how I go with it. It's had a pedal which slowly sank to the floor before but now it's worse. Brakes seem good, once you've pumped 'em up..... 😐