Swansen

Air keeps entering my brake system, i don't have any leaks, but there does seem to be some seepage through the cap where the wires go through the center for censor. So, i called the dealer, and they want one hondo ($100) for a cap, and i'm guessing the sensor as well. So, does anyone one know of a retailer i can find one???

thook

The cap is not where you're getting air from, though. That's a vent cap and air is supposed to pass through.

Usually, brake fluid shouldn't be passing through there unless you have the reservoir too full, you're taking your truck through rough driving so that fluid is splashing through, OR you have an obstruction in the lines so that when you press the brake pedal the fluid level is building up in the reservoir and pushing out. Normally, the brake fluid level goes down a hair in the reservoir when pressing the pedal as it's being pressed into the calipers and wheel cylinders, and then is drawn back up by the vacuum in the MC causing the fluid level in the reservoir to rise again.....a hair.

Whew....verbose enough, for ya?

Swansen

hmm.... yeah, makes sense, i wasn't completely for sure if that was the problem ether. That said, i'm not loosing fluid, but i'm getting air into my brake system?? i'm confused.

eric-the-red

One posibility is the master cylinder seals are getting hard and letting air in when the pedal is released.

thook

Well, maybe the MC is leaking at the pushrod seal? Have you looked there?

Swansen

Yeah, Eric might have something there, but its not leaking into the cab, and that whole area is dry. On all this, its a newer MC, replaced it not to long ago, but the problem came up when i replaced the brake lines to the rear drums, (lines that go from that y junction to the LSPV. Bled the brake about three times since then, checked to see if any of the lines were leaking, and nothing. Brakes stay air free for about 10 miles worth of stop and go....

thook

Assuming you bled the LSVP, did you notice much rust at the LSPV nipple?

Swansen

nipple??? do you mean brake bleeder?? on that.... hmm... i remember reading somewhere that there was only one condition in which you would have to bleed the LSPV. On that, the LSPV functions, but its very rusted, its on a long list of things to be ether replaced or overhauled. Yeah, but it doesn't make any sense that after bleeding the system its fine, zero air, and it just build back up?? seems like after almost a quart of brake fluid all the air would have been evacuated, but maybe i'm wrong, i dunno. On a side note, i replaced the bleeder on the LSPV when i bled it awhile ago.

thook

Yep....I meant the bleeder. I remember a while back having trouble getting all of the air out of the rear lines. The valve bleeder had rust on the tapered end and wouldn't seat all the way. Air kept getting though no fluid was leaking. So, I wondered if you were in the same boat.

All I can figure is somewhere at one of your new connections your having the same problem. No fluid leaking, but air is getting in. Did you install a prefabbed line or did you bend and flare the tube yourself?

Swansen

..... Yes, i think at this point i would have rather suggested i just completely restore my truck.... HAHA, yeah, well, that kinda solves that issue, i have a junction in the middle, but i tightened the crap out of them, so i doubt there is a leak there, but there was one flare that was kinda bad, but i was just like yeah, it should work, i just made sure to tighten it a little bit more than usual. Well... good times i guess, thanks for the incite.

thook

Yep....I've been there.

Good luck, Swansen. Funky brakes are a drag. Hope you get it fixed.