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Warning - defective brake lines

Old 06-26-2010, 09:00 PM
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strandolph
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Default Warning - defective brake lines

I recently bought a set of Apex steel braided brake lines (www.apexbrakes.com) from Rennsport Auto Parts via an Ebay auction http://cgi.ebay.com/ebaymotors/ws/eB...m=190343192615

Last weekend, they were installed on an 1984 944 NA running in the 24 Hours of Lemons. At the six hour mark, both front brake lines failed catastrophically under heavy braking prior to the Karussel turn. Both lines blew out of their crimp fittings simultaneously while the car was travelling about 80 mph at the end of a straightaway. The rear brakes continued to work for just long enough for the driver to throw the car into the banking then out--spinning to a stop short of the wall.

I know nothing about the manufacturer or vendor. They claim that the lines meet DOT and SAE standards. I don't know of any other cases where this has happened. I can only write about our experience and let you draw your own conclusions before using this brand of brake line on your car.

Pictures of the brakes lines:




Steve Randolph
944 Cup #3

Last edited by strandolph; 06-27-2010 at 11:38 AM. Reason: Added another photo
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Old 06-26-2010, 09:09 PM
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WOW.. Glad no one was hurt and the car is OK other than need new brake lines!
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Old 06-26-2010, 09:22 PM
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Just a bent tie rod via an overly-enthusiastic tow truck driver. We were back on track in 30 minutes.
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Old 06-27-2010, 01:38 AM
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Is it possible they were too short and getting pulled on in some turns?
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Old 06-27-2010, 02:02 AM
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Yikes! Glad you or nobody was hurt. Cetainly looks like a burst failure on the ends. What kind of pressure rating and what kind of fluid? I know it was heated up but as you say it has got to be stronger than that. Thanks for posting.
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Old 06-27-2010, 05:09 AM
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Ouch, glad nobody got hurt.
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Old 06-27-2010, 06:16 AM
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Does anybody know what type Paragon Products uses? I just got some and am skeptical now on putting them on my car, but I know there are many people using ss without issues.
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Old 06-27-2010, 07:49 AM
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Get them made up yourself at your hose doctor service. I use them for all sorts of hoses. Had a Jag that blew a power steer hose. Jag's price...$490.00, Pirtek's price....$80.00.

http://www.pirtekusa.com/
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Old 06-27-2010, 10:35 AM
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Mike C.
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That is scary all right. I've had (the same) SS lines on my car for 12 years or so with no issues. I think a few hours of track time on them too. I'll see if I can dig up the receipt... Glad to hear you and the car were relatively unscathed.
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Old 06-27-2010, 11:46 AM
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Originally Posted by TexasRider View Post
What kind of pressure rating and what kind of fluid?
Advertised at 3000 PSI. ATE Blue fluid.
Originally Posted by theedge View Post
Is it possible they were too short and getting pulled on in some turns?
They appeared to be the same length as factory although they weren't measured. I didn't personally do the install, but they were installed by an ASE technician who does a lot of 944 work and I'm sure he would have questioned anything that didn't look right.

Steve
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Old 06-27-2010, 12:11 PM
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Originally Posted by strandolph View Post
Advertised at 3000 PSI. ATE Blue fluid.

They appeared to be the same length as factory although they weren't measured. I didn't personally do the install, but they were installed by an ASE technician who does a lot of 944 work and I'm sure he would have questioned anything that didn't look right.

Steve
Looks like they pulled out or blew out. For those not familiar with this track, the section of track immediately prior to the this failure has a hill that makes many cars go light or off the ground. (I can go light in my slow azz 912 and fully 4 wheels airborne in my 911. This unloads the suspension and I wonder if the lines were pulled out rather than blown out. This could also explain why both failed at the same time. I don't think any lines stainless or rubber could take getting pulled on by the weight of an extending suspension. One line has a pronounced hard bend like deformity in the stainless bradding where the crimp ferrule ends.


Were the lines long enough (they look longer than stock) and run in the correct path? Was there a way they could get caught on something during a hard compression that could have caused them to be pulled on at the hill crest?
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Old 06-27-2010, 01:05 PM
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Originally Posted by kurt M View Post
Were the lines long enough (they look longer than stock) and run in the correct path? Was there a way they could get caught on something during a hard compression that could have caused them to be pulled on at the hill crest?
That's a really good observation. I would think that it was the more likely scenario.

If the failure was truly caused by brake line pressure, then both would have had to fail instantaneously, because once one side failed the line pressure would have immediately dropped.
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Old 06-27-2010, 01:31 PM
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DeeYAM!

Excellent observations... I'm glad to hear about the 'no drama' ending.
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Old 06-27-2010, 03:15 PM
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Originally Posted by Larry Herman View Post
If the failure was truly caused by brake line pressure, then both would have had to fail instantaneously, because once one side failed the line pressure would have immediately dropped.
Hmm, what Larry writes makes sense. It's possible that one line was coincidently pulled out when the tow truck ignored our tow hook and gaffed both A-arms instead, but there's no way to know for sure. There is a tear in the plastic coating on the line that has a rough look and hard bend at the separated end. The other line is cleanly shaped on the end and looks like the hose just slipped out of the crimp. The line that is "clean" also doesn't appear to have any trauma anywhere on the plastic coating. I would think that there would be a leverage point of some kind evident on the line if it were pulled out. But, we can't be sure. Doesn't seem likely.

The lines measure 18 inches and appeared to be routed correctly. They were installed by an experienced professional mechanic. During the heat of the moment, our focus was on sourcing replacements and getting the car back on track, so we might have missed some forensic research that would be valuable now.

Steve
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Old 06-27-2010, 07:41 PM
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Originally Posted by strandolph View Post
Hmm, what Larry writes makes sense. It's possible that one line was coincidently pulled out when the tow truck ignored our tow hook and gaffed both A-arms instead, but there's no way to know for sure. There is a tear in the plastic coating on the line that has a rough look and hard bend at the separated end. The other line is cleanly shaped on the end and looks like the hose just slipped out of the crimp. The line that is "clean" also doesn't appear to have any trauma anywhere on the plastic coating. I would think that there would be a leverage point of some kind evident on the line if it were pulled out.
In light of the added tow truck info, that is probably what happened IMHO.
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