Here are a few questions...
I woke up this morning to a nice puddle underneath my 4runner. I have determined that one of the metal brake lines is corroded and has developed a leak, dripping the brake fluid out.

However, since both metal lines are corroded, I'm thinking of replacing them both. I have no experience in dealing with brake lines, so here are a few Q's..

1) From what I understand, this is a two step process. One, replace the lines, and two, bleed the brakes. I was thinking of taking out the hard lines, bringing them into autozone ( I know, I hate autozone too) so they can measure them for replacement parts. Then replace the lines and bleed the brakes at the rotors. Now on the rotors, Is the bleeding valve right above where the brake line enters the rotor? If I replace both lines, I'd bleed both rotors.

2) Do I have to bleed the LSPV too ????

Any suggestions / tips, let me know!
Thanks in advance. <img src="/forums/images/graemlins/cheers.gif" alt="" />

if u are talking about the back brakes, then all u need to do is the following.

-Pump your brakes (engine on or off) & see if fluids are pissing/dripping out. If so, pinpoint location. If none, I can't really help here.

-get a c-clamp/visegrip & gently clamp (just enough pressure to compress the inside of the brake rubber tubing to stop dripping at next step) the rubber brake tube btwn the frame & rear axle.

-Get a close end wrench & make sure you can untighten the bleeding nipples (1 per drum, it sits above where brakeline enters drum backing plate) If yes, continue. If no, fix the nipple problem b4 proceding. If all fails, HEAT.

-Get a flare wrench & untighten the nuts on both ends of the brakeline you need to remove. Try lubing b4 attempting to loosen the nuts. it's tight, & u don't want to strip it either. If it still doesn't work, then use heat & fire the nut red with propane/oxy-ethelyene & quickly loosen the nut. Or you can just use a cutter to cut the brakeline close to the nuts, enabling you to insert a socket to untighten it by rachet. If all fails, HEAT.

-Do the same with the bleeding nipple of the lspv

-Get the exact brakeline size & fitting from store, & brake fluid

-screw the new parts in, tighten everything except the 3 bleeding nipples

-fill brake fluid reservoir to full & undo the clamp at rubber flex line.

-let the fluid drip out from the 2 backing plate nipples, a gentle pump from pedal will make it faster

-tighten everything, refill fluid if nessasary.

-get assistance to pump your brakes 5 times @ full travel, & hold at the 5th pump.

-You go to the rear right nipple & insert a clear tubing that fit snugly over the nipple. (ie. transparent rubber plastic thingy on cloth hanger) Insert wrench & untighten the nipple.

-looking at the clear tube, brake fluid will flow out along with bubbles in btwn

-tighten until assistance's brake pedal goes to floor, or no more bubbles coming out

-Tell assistance to let go after tightening of bleed nipple.

-Redo if not sure, 5 pumps & hold, untighten/tighten until no more bubbles comes out from line.

-go check resevoir, refill if nessary. don't let to suck try. Cause u'll have to bleed your master cyl if that happens.

-move on to rear left, then front right, then front left, then lspv.

-u are done.it's easy, but LONG... <img src="/forums/images/graemlins/cheers.gif" alt="" />

Thanks for your reply.... I was able to replace both brake lines with new line. The most interesting part was having to bend the line myself. We hooked it all up and bled the rear brakes. The brake petal sank to the floor when we started it up because I forgot to bleed the LSVP. Thats about the time that it started pouring rain. So, I'll finish tomorow morning.

Here's a question. If I only replaced the two brake lines for the rear, do I still have to bleed the front two brakes???

How far away do the brake lines have to be from the exhaust manifold? The ones I ran seem a little close, but I want to push them farther back against the firewall...
I'll try to post pics tomorow.
Wish me luck... <img src="/forums/images/graemlins/cheers.gif" alt="" />

Well, it's finally all done. I had to get a better brake bleeder, the rubber fitting that fits OVER the bleeder nipple seems to work the best.
Here are some pics of the old brake lines... They're broken in half at the place of the corrosion.


Note the rusted ends. I'm surprised that the lines held up as long as they did..



And the new lines:


Pretty good job. The toughest part of the whole thing was getting the compression connector tight without twisting the two connecting lines out of the shape they need to be in order to contour the truck.
And after bleeding the brakes, they're back 100%. <img src="/forums/images/graemlins/cheers.gif" alt="" />