Chevy & GMC Vans

I did my scheduled brake flush today. Every thing went well considering I had to apply heat to get the rear brake caliper bleed bolts loose. When every thing was done I decided to do a brake test while the van was still on all four jack stands. The brake peddle went to the floor. So I took a look around and found a puddle of brake fluid underneath the driver side next to the gas tank. Considering the brake lines are original I was not surprised that the brake line was leaking.

How do you go about buying new brake lines. Are they sold by the foot? Are the connectors standard thread? If so then I have a tubing bender that I can duplicate the original brake lines. I plan on replacing all the rear brake lines.

Did a Ranger recently. Autozone had the lines in straight lengths of varying size. Try to measure the line length the best you can, then buy the next size up. They come with the threaded connectors on them, but they might not be the right size. On the Ranger I had to cut one of the old ones off to install on the new line.

With an end's proper size connector installed, start bending from that end trying to match the old line. You should have leftover to cut off the other end. Cut, make sure proper connector is installed, and double flare.

Thanks for the tips Aaron. I will pick up a double flaring tool and am thinking of purchasing a 25' roll of tubing so that I can do all of the brake lines. What size brake lines do our vans have?

AutoZone has the double flaring tool available as a loaner, if you are feeling cheap. Don't now the line size our vans use, but a caliper on the old one will let you know easy enough.

Give me a call if you want a drinking buddy, I mean help and moral support.

don't quote me on this but i think the lines are 3/8ths . i've bone the lines on 2 88 astro's & 1 92 astro . the best way is from the filter back to the junction on the rear end , right where the rubber line connects to the rear . all 3 times we bought a 3' piece of line & a 6;' piece of line , started in the back with the longer line & had to cut & junction right in front of the tank with the 2 lines . yes a double flare tool is needed & a little patience getting the old lines out of the filter & rear junction , but it is doable . good luck .

Some of the lines are 3/16 and some are 1/4" . You will have to check what you are taking off but I ended up using some of both sizes

Southern, the brake line on my 89 rusted out above the fuel tank, too. Same with my 89 Safari. That line's diameter is quarter inch. I ran a new line from the brake line coupling near the fuel filter on back to the rubber hose that connects to the differential.
I don't remember what lengths of the quarter inch tubing I used (there were two lengths, if I remember correctly, that I connected together with a coupling to get the necessary length), but I didn't need to cut and double flare anything. That made it a bit nicer to do as I've never had much luck double flaring brake lines. But I went ahead and replaced the rubber hose along with the 3/16ths inch lines that run to the wheel cylinders. Naturally, the bleeder screws on the wheel cylinders were rusted tight and sheared off when I tried to open them, so I had to replace them. That's always been my luck with brake lines; you replace one and the project dominoes to include replacing all the rusted parts.

I dropped the tank to replace the line--I wanted it to follow the unit body frame rails like the original one, but I've seen where a replacement line is just snaked in above the tank and used like that with seemingly no problem.

Thanks for all the tips. I plan on starting on removing the old lines and go from there. If the autoparts store has the lines with the correct fittings I may go that route. Replacing the rear brake hose is also on my list of items to replace. Since my son is a Plummer/Pipe Fitter I may have him bend up some new brake line for me. I hope that I don't have to drop my gas tank, if I do then I will have to siphon out over 20 gallons of gas.

Southern wrote:I hope that I don't have to drop my gas tank, if I do then I will have to siphon out over 20 gallons of gas.

Nah, your fuel pump is good, might as well let it do it's job. Just disconnect the fuel lines between the drive shaft and the tank, put the line that connects to the fuel filter in a gas can and use the fuel pump jumper near the battery or a jumper somewhere else.

More info here

viewtopic.php?f=5&t=2233&st=0&sk=t&sd=a

ScottS wrote:More info here

viewtopic.php?f=5&t=2233&st=0&sk=t&sd=a

Nice work Scott. Did you replace your fittings? Were they SAE or Metric?

I finally finished with my new brake lines today. Yesterday I spent most of the day on my back bending the new brake lines in place (my arms are still sore). I ended up getting a 25' coil of 1/4" brake line and a double flare tool. I ran a continuous line from the front to the back. As for the connectors I bought an adapter brake line that had both fittings. I used pre-cut lengths of 3/16" brake lines to go from the block to the rear drums.

Now that I have new rear brake lines, it looks like my fuel lines might be the next to go based on their condition.

If your fuel lines go, you will definitely know it. A pinhole leak with 45 PSI of constant fuel pressure is gonna spray a lot of fuel, which will be almost mist like in quality. If they look that bad, replace them ASAP, the hot exhaust parts can make for a real bad day very quickly.

Seriously, take the time to do it now, before the snow and ice start flying.

Southern wrote:I finally finished with my new brake lines today. Yesterday I spent most of the day on my back bending the new brake lines in place (my arms are still sore). I ended up getting a 25' coil of 1/4" brake line and a double flare tool. I ran a continuous line from the front to the back. As for the connectors I bought an adapter brake line that had both fittings. I used pre-cut lengths of 3/16" brake lines to go from the block to the rear drums.

Now that I have new rear brake lines, it looks like my fuel lines might be the next to go based on their condition.

Did you drop the gas tank to run that line from the front to the back?

BigFish246 wrote: Did you drop the gas tank to run that line from the front to the back?

No I took a short cut. To do it like the factory did you need to drop the tank.