Makenzie71

I've read some commentary on not using a particular hard line...I have no hard line. Also, the male end of my brake line is about 1/8"~3/16" too long and bottoms out in the caliper before the copper washer contacts.

I'm going to just shave off some of the end of the line, but am I supposed to be using a different line?

gawdodirt

Been through this recently. The port on the caliper is for a flare nut, not a banjo or washer. IF they are really the 4-piston TII calipers. I went with Earls stainless -3 hoses and adapters. Works slick and about $80. Should last the life of the car now.

Also note the position of the bleeder. Just saying, it is easy to forget and easy to change sides.

GD

Makenzie71

They're Mazda 4-pots...that's all I can say. I did look in the ports and yeah there's a flare fitting. I'll just be shaving my lines to fit. Not dumping $80 into it.

I have yet to read anywhere that TII's have flare fittings on both ends of the brake line. Everyone says the calipers are a straight swap. This is nice.

Black91n/a

DON'T CUT THE LINE! It works fine as described. It does not need a crush washer. Just screw the one end into the caliper, the other end onto the chassis hard line, clip it to the strut and be done. Honestly, that's all there is to it, trust me, I've done it myself.

Makenzie71

I'll give it a try, but I don't see anything wrong with shaving it down and having that extra seal from a crush washer. The threads on these aluminum calipers aren't exactly nice and tight and sturdy.

clokker

iTrader: (2)

The banjo bolt is designed to seal with the crush washers.
If your bolt is too long to tighten down, then by all means, shorten it.

Also, pay attention to the boss on the caliper where the crush washer will seat.
Since these calipers were not intended for banjo fitting use, the flat surface was not finished machined and may not provide a good seal.
I screwed a short 10mm Allen plug into the hole (below the surface of the boss...the plug will keep swarf out of the caliper) and then dressed the boss face with a fine file to clean up the flat surface.
Not ideal, but it's worked on four sets of calipers so far with no leaks.

BTW, if you can't source a 10 x 1.0 plug, go to the junkyard and look at Japanese cars with ABS. The ABS units have all sorts of blind holes that are sealed with perfect little Allen head plugs.
Hondas seem to be a rich source.

Black91n/a

Yes, but if I understand him correctly, he's trying to use the single piston brake lines on the 4 piston calipers without the hardline that goes between the caliper and the strut. If that is correct, then there is no banjo bolt and the crush washer is entirely useless and by attempting to shorten the fitting, he'll screw up the taper on the end and it won't seal properly there. The hex head on the line isn't designed to seal with a crush washer, so there'll be problems there too, making a perfectly acceptible, sealable setup leak.

DO NOT CUT THE LINE! Connect it all up, bleed the system, clean off any brake fuild, then sit there and hold the pedal down for a minute with some force. If it doesn't sink to the floor and if there's no brake fluid detectable on the caliper, then it's sealed and you can move on to other things. Trust me, I've got this exact same setup on my car.

Makenzie71

You Canadians obviously have different brake lines.

My NA lines designed to seal with a crush washer, and there was no hard line between the caliper and strut...at all.

My TII calipers are designed to seal with a flared fitting.

I'll be doing what clokker says and shaving a seat onto the caliper and using a crush washer, and I'll shorten the male end on the lines to keep the whole thing from bottoming out before sealing.

clokker

iTrader: (2)

I see what you're saying.
It's been so long since I've seen the stock single piston brake lines that I can't recall what they are like.

Might as well try, you're the one looking at the hose so you should know.
Worst case is that it doesn't work and you'll need new hoses.

fc3s91

iTrader: (23)

I have a set of 4 piston brake lines fs. $100 shipped ( includes all four stainless steel brake lines.
Thanks Robert

Makenzie71

https://www.rx7club.com/2nd-generation-rx-7-1986-1992-parts-194/

Makenzie71

Anyone see any issues running a 4-pot on one side and the single on the opposite for about 40 miles or so? I'm doing the swap during my lunch break...don't quite have time to do both sides.

clokker

iTrader: (2)

Just wait and do both at once.
Why bleed the system twice if you don't have to?

Makenzie71

30 minute breaks...only really have time to do one side. I have too many customers' bows to work on after hours...between that, the missus, and the baby...I have no time at home until the weekend (maybe). My pass side caliper is binding up and needs to be replaced asap.

I have a vac bleeder...bleeding the system takes like one minute. It's awesome.

Makenzie71

Crap...need a quick answer! My wheels rub the 4-pot calipers. There's a little raised nub on the caliper face. Can this be shaved down a few millimeters?

jjcobm

iTrader: (18)

I few millimeters will be fine, the housing is really thick.

Makenzie71

Is there a passage in that elevated area that connects the pistons or something?

I stacked washers on the lugs and had to lift the wheel off the rotor 3~4mm...would that be safe?

gawdodirt

Good luck and pay up your life insurance for the missus and the baby. Go fast and hit your brakes really hard. The importance of this system will be come apparent.

Trying to "machine " a parallel sealing surface with a flat file. . You may get lucky. If you don't grasp the possibility of a difference between a single piston caliper and a 4 piston unit, than maybe brakes are not your issue. Also, I did a trial fit for wheels before I installed the calipers as both pieces do flex and you will need more than a few mm of clearance.
Not flaming, just trying to really state the importance of conventions in brake system engineeering and the need to not f*** with it.
GD

gawdodirt

whatever.....

Makenzie71

You don't have to have a perfectly machined surface for a copper gasket to seal against. I have proof sitting on the car right now: Copper gasket under the flare and no pressure variations, and no leaks.

And my question about "is 3mm safe" isn't "is it safe to drive this way". Is it safe to take that much off the nub on the caliper...and I'm asking for info from someone who understands how the caliper is made, not someone whose just installed a few.,

gawdodirt

Maybe a pic would be more appropriate. Of the nub of the caliper of course.

gd

Makenzie71

I'll get some up here in a bit...I have to baby the thing home first. Make for a long, slow 18 miles. Frustrating because I know people here with TII's and GTU's are running the old Lincoln Speedlines without a problem...

Makenzie71

Actually solved the issue...a friend of mine here can get me some spacers for like $4 a piece...only has 5/16" (8mm). That'll give plenty of clearance, but I have to worry about stud length. May have to get some longer studs.

Makenzie71

Well I sourced the 5/16" spacers but I don't like them. They don't center (I have no idea how they're supposed to be centered), and they're really too big. So I go back to the caliper...I would like to shave a little off that "nub", and I want to find a 1/8" spacer (will find tomorrow).

Here's the "nub" I'm talking about:





Is that a raised area for an oil passage? I need to take 2~3mm off of it to get the clearance I would really like.

clokker

iTrader: (2)

Yes, that bump holds the passage between the two pistons.
I had to file one of mine down to clear some wheels and it was fine.

I always meant to file that caliper down till I broke into the passage, just to see how much room there is...but I never did.