brake line

[DADGLW]

the brake lines on my 3500 dump are all rusted out and leaking.. are they covered under warrantee? i have a little over 33000 mile on it.

[More Power]

There is a 3-year corrosion and 6-year rust-through warranty, but these cover the sheet metal. I couldn't locate any mention of fuel or brake lines in the warranty booklet.

Talk to your dealer....

Jim

[DADGLW]

i took it to the dealer and they said it was covered under the 3yr,36000...thanks

[DADGLW]

got my trk back today...fixed brake line on drivers wheel, they cut out rusted part and put in a section of line using compression fittings... is this common practice? i even had to bleed the system again!!!

[More Power]

I tried to buy a complete set of steel fuel lines in 2004 for the Duramax. Long story short, the lines weren't available. The dealerships "repair" lines when and if they need it. So, I'm not surprised at what you received. Compression fittings are fine as long as they are the correct type and design.

I talked to a guy a couple of years ago who bought an older GM diesel truck that had been a part of a fleet, somewhere in the upper midwest (rustbelt). The company included an under-vehicle spray as part of its semi-annual service. The "spray" was what appeared to be just plain old oil. I haven't heard form anyone else about this type of proactive corrosion protection.

Jim

[JohnC]

I always thought compression fittings were prohibited in brake systems. Has something changed?

(Even if it has, I still don't think I would do it...)

You think the dealer should have bled the brakes for you? ;)

[More Power]

A compression fitting is what the terminates most steel brake lines (transition to flexible line or Y-block like that above the rear axle). Banjo fittings are also frequently used at the calipers. As long as the repair used the same type of fittings, it should be fine. I don't remember the exact name, but the industry uses a some sort of double flare at those fittings. ;)

Jim

[JohnC]

I think we're talking about different things. A flared fitting is fine. A compression fitting (in my mind) uses a soft metal ball (ferrule) with a hole in it that slips over the line. The union and nut compress the ball and it squeezes the line. OK for low pressure only.

[More Power]

Of course you're correct. I was thinking about one thing and typing another.... A flare fitting is the way to go...

Jim

[JohnC]

So, I wonder what they used... :confused:

[DmaxMaverick]

I always thought compression fittings were prohibited in brake systems. Has something changed?

(Even if it has, I still don't think I would do it...)

You think the dealer should have bled the brakes for you? ;)

They are prohibited. Compression fittings are not DOT approved for brake systems. The repair should have been a flare coupling. Even high quality aircraft type compression fittings are no longer approved for aircraft critical systems (are any of the systems non-critical?). What you do under your shade tree is your business (as long as it's safe), but I can't imagine how a dealer justifies it. The line should have been replaced, or properly repaired. An automotive brake system can exceed 3000 PSI. There are NO compression fittings rated for this (3000 PSI is the max), and are only rated at 3000 PSI when used and installed properly and with the correct materials. Automotive brake lines are not among the materials approved (unless they're using annealed CRES). The high pressure compression fittings were/are steel cylinder-shaped sleeves, approximately 2-3x longer than the line diameter, with a raised band in the middle. NOT the little brass balls used in low pressure plumbing applications (like that used to connect a refrigerator ice maker). They may work initially, but will fail at some point, and not likely when it's convenient.

Eons ago, I had replaced/repaired hundreds of aircraft fluid/pneumatic lines with compression fittings (on military aircraft, mostly Vought and Lockheed). It was approved and accepted at that time, and took a fraction of time and effort compared to alternative methods. Before I moved on, they were ALL slated for replacement with flared, swaged, or welded fittings. All of the aircraft that were approved for compression fittings were 1960's era. None of the later aircraft were ever approved for compression fittings.