billthe3

I went on the rennlist drive this weekend and when I left my house the brake pedal was immediately stiff, no freeplay at all.

However, after driving about half of the run (420mi total) I noticed the brake pedal had an inch or so of freeplay before the brakes would become hard. Listers suggested I check the lines and whatnot when I get home.

So, when fixing the shift linkage the shop screwed up today I looked at the rear lines and it looks like one of them has failed, or something. It appears as though the fluid, or the lining of the hose, has worked its way out through the SS mesh. I put the hoses in clear heat-shrink to protect against any possible rock or debris damage, so I am unsure what the stuff feels like, but it is definitely more black/dark brown colored than the ATE super blue fluid I'm running.


Any ideas what has happened here? The pictures are the good line on the drivers side compared to the messed up line on the passenger side.


I still have the stock lines I can put back in, but I don't think I'll be driving the car much anyway because the *new* clutch master cylinder has blown even worse than the first one, so I need to get that fixed. Looks like I get to go through the fun of bleeding all this crap again....



*Not trying to diss paragon by listing their name in the title of the thread - they're awesome. Just posting that because I'm too lazy to contact them tonight so I'm hoping Skip will see this and post thoughts. lol

Luis de Prat

Back in the day of Porschephiles the consensus on SS braided brake lines was that they were great for track applications on cars that had their brakes checked very frequently but that they weren't really suitable for street use.

Porsche doesn't fit them stock for a reason.

billthe3

Thats fine and dandy, but how the hell are they supposed to be for race use if they can't even last 450mi on brand new fluid and thurough bleeding?

Litterally, these have only been on for the 450mi since the car has been running for the two weeks after the 8 months of living on jack stands. I don't see how you can get the brakes to be checked any more frequently.

And it appears to be an internal failure, so it wouldn't have mattered where the lines were used.

caster951

Bill,
Shoot me a pm if you want, I have a single rear stainless line in great shape off of my 83 that I parted. It has about 1000 miles on it and I broke the other one removing it, dumb mistake. If you want it send me a paypal for shipping and it is yours.

schwank

Bill I have paragon SS lines on my car and have driven it about 2000 hard miles since installation, probably 90% track. No issues to date on front or rear. Maybe you got a defect.

brad-cam

I also have several thousand hard miles on my SS lines with no problem. What's the black crap, can you tell ? Is that the carbon from melting the heatshrink ? Could you have overheated the line (assuming you did heatshrink the line)? Lastly, any chance the fittings weren't tight? Definitely strange. You don't really need the clear tubing IMHO. I think the SS sheath is as durable or more so than the plain rubber stock hoses.

Mike C.

Stainless steel passivates in air (forms an thin chromium oxide that prevents it from corroding). Maybe the plastic tubes were sealing it up too well and atmoosphere became oxygen defficient. When you get it apart see if it looks coroded.

bluedevil

Sounds like a defect, I have had SS lines on my 944 for about 3k miles with no problem and I get them inspected and I look for myself with no issues yet.

JayP

The reason the SS lines are not the preferred street equipment is they're usually not DOT certified- even if they surpass the standards of regular lines.

It looks like the connection to the flex line has become loose and allowed fluid out. The plastic on the lines isn't a bad idea- I've seen them on other kits to protect against rocks, etc.

schwank

The paragon ones are DOT-approved and labeled as such, and come with a clear plastic-like coating to begin with. I installed mine with no further coating at all.

jaje

From talking with other racers...ss lines prevent the bulging you can get with rubber lines when you are braking hard and the lines get hot (reducing some fade and giving you a stiffer pedal). However if they are defective or you kink the link by bending them more than 90 degrees while installing them or hanging the caliper by the ss line alone while swapping discs may allow the nylon inside the lines to bubble out the area damaged and eventually burst (sometimes with little to no notice).

I had ss lines on a track car that got knicked by what I assume was a rock. Part of the ss area started to fray and inside the line is just simple nylon that when it is no longer completely held in by the ss line, the nylon will bubble through the ss and then pop (I unfortunately found out the hard way in turn 10 at Summit Point - though did get the car slowed and recovered without going off). The way I figure ss lines act like an exoskeleton (similar to a bug) and it is very strong and does not bulge leading to a much firmer pedal under racing conditions than a rubber line...but once there is a fracture in the ss exoskeleton...the pressure of the fluid in the lines will make the very weak nylon break through that fracture).

pjburges

jaje - If what you say is true, the design largely seems to defeat one of the purposes of a SS line. Im not trying to say that what you said is BS - just that it would be shocking to me that a group of engineers would design such an important line like that and leave no stress margin in the design if the SS sheathing were to fail. Maybe Ill just stick with the rubber ones.

heavy fuel

Did you heat the heatshrink? if so, it is possible that you damaged the internal plastic enough to make it extrude through the SS braid. if it's really nylon, it can get damaged by relatively low temperatures. I thought they were teflon inside, which would withstand the typical heatshrink temperatures much better.

GodSpeed

Ive had SS brake lines on my car for a few years now. No problems at all.

Mike C.

I've had them on mine for over 10 years with no problems at all (and no plastic coating), nor are mine DOT approved. Something is seriously wrong; a manufacturing defect or possibly installation problem (could it have been twisted to much?).