Stupid brakes

[lukecp]

I was checking fluids on my truck the other day, and i notcied my brake fluid was a bit low in the rear resivour. No big deal, so i filled it up. Today i went to stop the truck, and i felt the brake pedal sink underneath my foot more than nomral, so i checked it again, and sure enough, it was low. I started looking and found that the brake line for my rear brakes, the one that crosses the front suspension X-member, had worn a hole in where it meets the frame. No big deal, so i took out the old line, and went to the parts store and got a universial bend-to-fit replacement. I put it in with no problem, and went to bleed them with my mity-vac bleeder.

Anyway, i was just pumping air and no brake fluid, and the level in the MC wasn't dropping, so i got in the truck and stood on the brake pedal to check for a leak. Sure enough, the brake fitting was leaking where the lines join going from the mastercylinder and the one that goes across the X-member.

The fitting on the new line is the same thread as the old line, and it seems to be leaking where the line goes into the fitting that slides up and down the new brake line. I was thinking of just replacing the union for the two brake hoses and seeing how it works then, but that is just a guess. It didn't leak before and it looks fine. Any other ideas on what would make it leak like that?

[Blue_71]

i gotta ask, did you flare it before putting on the fitting?

[lukecp]

Yup, the line was pre-flared with the fittings on it.

[greg72]

I hate to ask this but I ran into it. The replacement line isn't metric by any chance is it? Just enough smaller to leak but not enough to be detected????

Just a thought

[JimKshortstep4x4]

Sometimes you have to tighten the fittings a lot to make the old and new flares seat.

Jim

[crazy longhorn]

another thing to look at, is that the flared end of the new line is smooth......I have seen new lines with a small crack in the fold on the double flare. Also I have seen a small pc of rust or dirt get between the line & its seat, causing a scar.....some of that stuff will make you "nuts"! I would try tightening the line more, as Jim has suggested tho..... good luck,crazyL

[lukecp]

Well, i torqued down the lines until the end on my cheap flare wrench spread apart, and that seemed to solve the problem. I wrapped some paper towles around the fittings at both ends of the line, got in the truck, and pumped up the brakes. Both towels were dry, so that solved the leak problem.

However, i am having problems bleeding the brakes. I am using a Mity-Vac pump, which seems to work good so far. I will pump it up, open the bleeder valve at the wheel cylinder, and i have been getting LOTS of bubbles in the system. I have filled up the container with about 2" of brake fluid 2 times, put the fluid back in the MC, and now the pump is drawing just air and no fluid at all.....and the level in the MC isn't dropping at all. I haven't found any other leaks in the brake system, and i have the fitting for the pump on right (the vaccum guage shows no drop in vaccum when i hook it up with the bleeder valve closed).

Also, if i go pump up the brakes after i get nothing but air out of the bleeder fittings, i will then get a mixture of air and fluid (mostly air though)

Brakes have never been my strong point. What am i doing wrong here?

[lukecp]

Also...
I have been bleeding with both the MC cap on and the MC cap off, and it dosen't seem to make any kind of a difference.

[crazy4chevs]

Try bleeding the M/C the oldfashioned way then when done rebleed the system.

You probably got air in the M/C

[JimKshortstep4x4]

I think that you have Murphy helping you!

Rear brakes can be a real problem to bleed sometimes. I am wondering if your prop valve has not shifted. I would try bleeding the master cylinder and the prop valve by removing the line from the rear of the prop valve. Once your fluid flow is good through there go back to the rear and try again.

Good luck it will only take two more days to get it bled!
(Just half kidding!).

Jim

[lukecp]

Woo Hoo! They finally work again.

I bled them the old fashioned way, using my sister to press the brake pedal, and i layed down by the bleeder valves using a bottle of brake fluid and a clear hose. Took like 5 minutes and the brakes work great. This is acutally my first successful brake job, lol.

Now, one more question. The replacement brake line dosen't have the wire shield wrapped around it like the original did. I can't put the old one back on, so i bought some 3/8" fuel hose to wrap around the line where it comes close to the frame. Think this will keep a hole from being worn in the brake line again?

[CPNE]

That wire wrap is on the OE lines only to allow them to be factory pre-bent without kinking the brake lines. It's not there to protect the lines after install though I suppose it would to some degree.

[JimKshortstep4x4]

The springs are put on to protect from stones and debris damage.
I think what you did will proect it from wearing through. It is a little unsual to have a line wear through as they are usually held securely against the frame.

Good job!

Jim