MKIII Brake line to MKIV Caliper, (A fitting question)(Pics)

[turbogate]

Ok guys, I'm getting ready to install my rear MKIV TT Brake to go with my Arz front kit. I have everything already, at least I hope. Here's what I need to know. From Djonez's website, 4cefed.com, on his write-up, he mentions that the MKIII rear brake lines bolt right in. Based on that, I ordered some rear only braided lines from Techna, since the front kit already comes with its own lines. Our brake lines on the rear, does not use a banjo bolt like the MKIV does, it kind of bolts straight to the caliper (you will get a better idea with the pics below). Therefore the techna does bolt right in the MKIV caliper, the only thing i need to know from you guys, is whats the right way to seal the line to the caliper. Please see my presentation, as you will understand my question better.:icon_bigg

This is the Techna line fitting, next to the MKIV banjo bolt with copper washers.

A better picture of the techna MKIII line/fitting

As you can see, the techna line bolts right in the MKIV caliper, but leaves a gap than can be eliminated only by a washer as thick as the 2 copper washers. Keep in mind, that this is hand tight, but I dont think it will go much further.

Lastly, a picture that shows the calipers' insides :icon_bigg

Basically, I just need to know, whats the best way to make sure it does'nt leak, more importantly, that it works. Do I find a copper washer thats thick enough? Is it good practice to use 2 washers like the picture shows? (no flame please) Teflon tape? It does not look like those fittings that will just seal as they get tighter, I might be wrong though.

I didn't go with MKIV lines, because apparently they are a little shorter than our brake lines and since it was mentioned that our brake lines work, I just upgraded my lines.

Thanks

 

[AF1JZ]

If you look at the hole where the line goes into, there should be a rubber grommet thing. That will do most of the sealing. It wouldn't hurt to use some teflon tape.

 

[TurboStreetCar]

By the look of the end of the brake line its a flare fittng. when its tightened, the metal fitting at the end of the line gets pressed to the metal inside the caliper making a seal. Or thats just the way it looks.

How did it seal into the stock caliper?

 

[Poodles]

they use the copper washers IIRC...

 

[turbogate]

By the look of the end of the brake line its a flare fittng. when its tightened, the metal fitting at the end of the line gets pressed to the metal inside the caliper making a seal. Or thats just the way it looks.

How did it seal into the stock caliper?

I haven't pulled the stock caliper yet, once I do, it will probably answer a lot of my questions as to whether or not the techna line is a flare fitting.

 

[supraguy@aol]

I would use teflon tape, but because it is a flare fitting, I would go without the washers. If it leaks- it won't be that much trouble to remove the bolt and install said washers anyway.

 

[IJ.]

WHOAAAAAAAAAAAAAAAAAAAAAAAAAAAA!!!!

Look at the Flare seat inside the caliper, see the hole is offset?

No way will it seal on a flare end of a hose.......

Teflon on Brakes??? WTF it's NOT a tapered thread Teflon will do jackshit guys!

I don't mean to come across as harsh but Brakes are the one place where there is 0 margin for error use the correct fittings for them.
(I worked in the industry for a few years when I was a kid and saw so much of this sort of thing you wouldn't believe)

 

[turbogate]

WHOAAAAAAAAAAAAAAAAAAAAAAAAAAAA!!!!

Look at the Flare seat inside the caliper, see the hole is offset?

No way will it seal on a flare end of a hose.......

Teflon on Brakes??? WTF it's NOT a tapered thread Teflon will do jackshit guys!

I don't mean to come across as harsh but Brakes are the one place where there is 0 margin for error use the correct fittings for them.
(I worked in the industry for a few years when I was a kid and saw so much of this sort of thing you wouldn't believe)

So what do you suggest IJ? the reason I posted the picture of the inside was to show that the hole was actually not centered. therefore leading me to believe that it would not seal like a flare fitting would. So is all I need is a thick copper washer? can 2 be used? I'm not taking chances on my brake system which is why I'm asking. If I have to sell these to get MKIV lines, I will. I just need to know given what I have, whats the way to connect the lines.

Thanks

 

[IJ.]

Personally I'd find a local brake shop and take them some samples and have correct lines made up to suit your combination.

(this is how I did my AP Racing 4 spots as they use a banjo fitting like the Mk4's)

 

[Aspec]

"If" the threads on your stainless hose fitting that goes into your MK4 calipers is the correct thread and pitch (which it appears to be) you can try the following:

Cut down the end that goes into the caliper so it does not bottom out when installed. Leave it as long as possible. Cut or grind off only enough to keep it from bottoming out in the caliper.

Make sure to make an extremely clean and straight cut paying attention to where all of the filings go. Keep them out of the hose! Round the cut end to give a slight taper so it will start easier.(if you had to cut into the threads)

Then use "1", I repeat, "1" washer only to seal it. Never stack washers on hydraulics.

Never use any thread sealant, of any type, on any brake application.

Once it is assembled and bled, clean off any brake fluid residue and check for leaks. Now check for leaks again. Now stomp on the brake pedal a few times. Now check for leaks again. Go for a short drive then. . . check for leaks again.

 

[IJ.]

ASpec: I'm not too keen on using straight fittings on that type of calliper inlet as it puts the hose end at 90 degrees to the calliper body

 

[Aspec]

ASpec: I'm not too keen on using straight fittings on that type of calliper inlet as it puts the hose end at 90 degrees to the calliper body

Doesn't the stock line on the mkIII go into the rear caliper at a 90?

 

[IJ.]

Does it?
(not being a cock can't remember it's been so long since I've had stock brakes)
(I thought they angled down)

 

[Aspec]

Does it?
(not being a cock can't remember it's been so long since I've had stock brakes)

I edited my previous post to add an attachment:icon_bigg

 

[jdub]

IJ - You've....changed

 

[IJ.]

Shhh

 

[Aspec]

Shhh

I wasn't going to say anything but. . .

 

[turbogate]

This picture is borrowed from Djonez's website www.4cefed.com. The MKIIIs line is similar to that with more or less similar fittings. Look at where my arrow is pointing. It seems like a similar type of fitting like my techna fitting, except that it is flush with the caliper with the help of what looks like a copper washer.

Aspec, my mechanic friend did suggest the same idea (cutting the fitting a tiny bit) so it does not hit the bottom, then using a copper washer. I dont see why that shouldnt work if sealed properly. I'm hoping Djonez can give some insights as well.

 

[supraguy@aol]

wow- I wasn't aware of the no-teflon rule. In fact, I thought that my brake lines came with the suggestion of using teflon- doe sit deteriorate in brake fluid or something?

 

[Aspec]

wow- I wasn't aware of the no-teflon rule. In fact, I thought that my brake lines came with the suggestion of using teflon- doe sit deteriorate in brake fluid or something?

You do not want anything in your brake fluid but brake fluid. Anything else can change its characteristics (boiling point) not to mention what little floating bits of crap can do to your internal seals, master cylinder, abs parts, etc...

As for teflon deteriorating in brake fluid, if left unchecked brake fluid will eat through paint so my guess would be yes.