I just noticed that classic tube has a brake line kit for 1997-2001 Grand Prix'*. I have been fighting for months on end with a nearly whole car brake line overhaul on my 2004 GTP Comp G. The problem is that with the brake lines snaking up behind the ABS unit, its ridiculously difficult to get the lines in the right places without dropping the engine cradle out of the car... which is not an option.

Now that I have the car back together, and I'm bleeding it, my copious unions are leaking and I have to tear half the car apart to really crank them together. I don't know exactly what the issue is with the unions. My flares are good and I'm fairly sure the fittings are all correct... but I think some of the unions I bought are of a poor design.

Nonetheless, when I last looked at a '99 Grand Prix it looked like the brake line setup was exactly like my 2004, but it was a long time ago. Do any of you guys know FOR CERTAIN if there are any differences in the brake lines? Classic Tube is listing 1997-2001... did something happen in 2002 that changed the lines?

I'd like to try the lines from Classic Tube... even if I have to slightly tweak them... but I can't make a $300 gamble to find out they are totally different.

BKNJ

Anymore brake lines are all custom work done at a shop. Get yourself a 25 ft roll of tubing , a kit and go to town.

Already there and have the T-shirt.

But that'* not necessarily the only option... Classic Tube has prebent kits for many cars, pre-2000... and newer trucks. GM'* awful brake lines have spurred on cottage industry. However, they don't stock a 2004 GP kit.

The problem with a running the lines yourself is that the W-bodies are just too tight and inaccessible to fit the lines in properly, so you end up with them rubbing and vibrating, which can make them brittle and corrode. And if you don't eliminate the flexible stainless braided part, all of your unions end up behind the ABS pump... and you don't find out which might decide to leak until you bleed the system. To fix the leak, you have to tear out the master cylinder and ABS and if your lucky you can crank the unions a quarter turn tighter in a very confined space. Then put everything back together... bleed again and hope for no leaks.

That'* where I am. I have had to pull the system apart three times now for unions leaking... and I await bleeding it again. Contrary to appearances, I am VERY good at making inverted double flares, but the old GM line sucks... and I am questioning the unions I got.

At some point, if I can't get the system bled, I'm going to have to try the older prebent GP kit from Classic Tube, as I can't deal with so many points of failure (leakage) that all these unions create.

I was comparing the parts diagrams on naleygmc.com... and the 1999 and 2004 GPs both use the same exact picture... the fronts are part "9" and the rears are part "28". Even the most of the part numbers are the same, though the descriptions make it sound like they aren't the same part.

1999 GP with JL9 - Rear RH: 10407739 Rear LH: 10407740 Front RH: 10335973 Front LH: 10425230.
2004 GP with JL9 - Rear RH: 10407739 Rear LH: 10407740 Front RH: N/A Front LH: 10425230.

For $240 I could buy them from GM... or for $239, I can get the entire car in stainless from Classic Tube... _IF_ the 1997-2001 parts would fit on a 2004.

I'm leaning towards the idea that they will fit. I suppose I could call them and ask just how exact these are... compared to the OEM stuff.

BKNJ

I have notice some GM cars are using bubble flare
and some are using inverted flare.
My 2001 Regal uses bubble flare
But like a 2006 impala uses inverted flare
{AT lease on the rubber brake lines}
Your 2004 GP uses bubble flare I would check a 2001 front brake hose
to see if its bubble flare or inverted flare
Do you need all the front brake lines?
Here in Texas might be able to find you some that are not rusted

The newer car brake lines have protection on them....something European/Asian cars were doing for years...

Oh, no... I needed to replace about 75% of the hard brake line on the '04 Grand Prix... and 90% of the hard line on my '99 Bonneville. That'* how I learned of Classic Tube... they have a full kit for the '99 Bonneville... and in retrospect wish I had bought it.

Both cars use bubble flare for all connections... except the '04 GP has two inverted double flares under the driver'* rear door. They use a connector that joins a bubble flare directly to an inverted flare... but each one is reversed, so that you can't mix up the rear line at that junction.

What killed me working on the '99 Bonneville was that I bent up a perfect 80" line to find out I used bubble with metric fittings to find out it needed bubble with imperial. Ugh. I'm going to have use adapters now and adjust an inch out of the line.

Anyway, the situation on the '04 GP is that I bent and replaced 75% of the lines... added about a dozen unions... and every time I bleed the system, some random union springs a leak and I have to completely take apart the ABS unit to get to the union to tighten it up. Thats the reason for the original post... I might be getting to the point where I scrap it all and try buying an hard brake line kit for a '97-'01 GP and hope it matches the '04... which I'm fairly sure it will.

Unfortunately, Classic Tube has not answered my email to tell me if the kit is for ABS or non-ABS cars.

In the meantime, after showing the unions to a friend, he agrees that they look like they are for bubble... even though the boxes they came in specifically state inverted double flare 3/8-24... so if you are shopping for unions at Autozone or Advance, look inside the unions before buying them. If they don't have a raised bit to match the inverted flare, get them somewhere else. The ones I got at NAPA seem to be much better.

BKNJ

Would it help to find you not rusted up {one piece} brake lines here in Texas?
lots of cars here have no engine or transmission in the way and are evaluated
So easy to take some thing like that off
I think your asking for trouble using unions
what happens if you stomp on the brakes hard in a panic situation
and you have no brakes ??

Probably not. Part of the problem is that GM seemed to change the way their lines were made in the late '90s... and several vehicle lines have become notorious for brake line rot... Chevy trucks for certain. In my case, being in NJ at the shore, I get the double whammy of road salt and sea salt in the air. Getting used OEM lines would probably only last a few years before the same problem occurs... keep in mind that the lines rot from the outside AND the inside (water in the brake fluid). The aftermarket lines come in a couple flavors that are clearly more rot resistant than OEM... and companies like Classic Tube sell Stainless lines which will likely be one of the last things left after the rest of the car has rotted away... the reason for my interest.

GM seems to still stock (at least according to the web) some of the lines... but they are so expensive, that buying the full stainless kit makes better sense. Why pay hundreds of dollars for new OEM when the originals only lasted 9 years (in the case of the '04 GP, when this project started).

As for unions, once they seal, they are just as safe as the rest of the line. Unions are a legal solution, unlike compression fittings... which are not designed for the pressure levels a brake system sees. I've never had a union fail in service. Only time I've had union problems is recently with the batch I've been using to fix first my '99 Bonne and then the '04 GP.

That said, I am a perfectionist/mildly-OCD, so even if the unions work fine, it still bothers me to have a lot of them on the car. If I knew how long and drawn out this project would become, I would have ordered the stainless kits.

BKNJ

I know were your coming from I spent 18 years in PA.
were you use to see cars in the junk yard with 35k on them
all rusted out from the road salt.
You adjust your seat back and the back of the seat falls threw he floor.
Or you open the hood and the hinge pulls out of the body.
2 year old cars and the wheel wells all rusted out.
Its not as bad as that now but the undercarriage sure gets it bad
in a lot of areas.