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Working my way through the Lola and had a chance to look at the rear brake line plumbing while I was removing the calipers. I don't like it. Right now I have a soft line running to a tee fitting lying loose on top of the gearbox and then two soft lines running one each too the calipers. Considering replacing all the soft lines with hard lines. Any down side to this? Curious what others have done?
Not a single piece of hard line in any racecar that I've ever built.
Not a single brake related failure either.
I've built a lot of racecars.
Hard lines have to be VERY carefully installed to prevent fatigue failures, plus they're a PITA to properly flare, bend and install. I've not used a hard brake line on a racecar since the Z10 in the '70's.Quote:
Originally Posted by aero_eight
You do have to be careful that the SS braid on a soft line doesn't rub on ANYTHING because if it does it will either wear though what it's rubbing on or the SS braid will itself wear through causing a brake failure.
Any soft line that's vulnerable I cover with 1 or 2 layers of shrink tubing to protect it.
https://www.apexspeed.com/forums/sho...l=1#post555865
Quote:
Originally Posted by DaveW
This is what I do on every inch of -3 stainless.
I get the 3' lengths of shrink tube from McMaster Carr.
Or, if money is no object, you can buy coated Earls -3. It is nice, but price is up sharply form a few years ago....
bt
My Lola 644 had hard lines and were troublesome. Didn't have a flare, but a bubble like fitting.
Ed
I still have my tool to make the normal and SAE/double (inverted/45degree) flares. Haven't used it in >30 years.Quote:
Originally Posted by EACIII
Both of my Van Diemen cars have/had a hardline from front to rear, both clutch and brake. No issues on the RF79/80.
I'm surprised there is that much hate for hard lines. Its easy to work with, the flare tool, if you don't have one, is cheap, and I've never had one fail. In theory it should be less compliant than any hose in regard to expansion under pressure. Yes it takes a bit of planning (flare the tube and forgot to install the sleeve or B-nut) but you usually only make that mistake once!
If you ever watch a formula car of that era at speed from behind, you will notice the engine and transaxle move under acceleration, gear change and hard braking. Soft lines where they have to flex with the motion are preferred.Quote:
Originally Posted by aero_eight
DaveW is correct about fatigue failures of hard lines and also sleeving the braided stainless because it acts like a hacksaw to anything it touches.
10rmotor is also correct about flaring hard lines. What you have are the English "bubble flares" which are made with the same tool you use to make double flares, just without the second operation to make the internal flare.
My Crossle and Zink have hard lines to end of the chassis and then braided lines to the calipers. The hard lines are fastened to the chassis with padded 'p' clips so they don't move. Soft lines are allowed to flex so they can.