Get a service manual if you plan on working on your vehicle. Lots of information that will assist you in doing repairs.
Glad to see you are taking an interest in working on your vehicle. BUT, if you are stumped as to how to do this fairly easy job, it is best if you get someone with some posative experience to do it for, or with you. It's a major safety related and potental liability issue.
I've replaced my master cylinder with one of my friends. Replacing the master is easy, so don't fret. You might want to have an extra set of hands to hold stuff, and you'll need it to bleed the system. Removing the old master is just a matter of loosening the brake line fittings that screw into the side of the master and removing the nuts that hold it to the brake booster. as far as removing the booster goes, I've never done that before. But back to the master... First, empty the reservoir of as much fluid as possible. You don't want it staining your driveway or eating the paint away on your truck. Second, remove the fittings from the side of the master. You may need a special wrench to do this. Third, use a ratchet to remove the nuts that fasten the master to the booster, and pull the master toward the front of the truck. The master should slide straight out. Keep the old fittings if they came off, you'll need new ones from the parts store... If you need new fittings, sometimes it's cheaper to buy new sections of lines that come with two fittings than it is to buy just the fittings. Anyway, next you want to remove the brake booster. I've never done this, so I'm just gonna skip to the installation of the new master. You want to bench-bleed the new master cylinder. I didn't do this, and I think I still have some bubbles in my system. So bench-bleed your new master. It should be just a matter of filling the reservoir, and and pushing the piston back and forth with a screwdriver to get the new air bubbles out. Your master might have come with a bench-bleeding kit, so if it did, follow the directions. Anyway, after the master is bled, hook the hard lines from the proportioning valve (the lines from the old master that you just disconnected) up to the new master, and re-bolt the master to the booster. Before you do this, make sure the push-rod is all the way out. So just pull it out of the booster, and slide the master over it and bolt it in. Then bleed the system. Project done.
thx alot dude. one question tho. in the haynes manual there is a wire going to where the brake lines meet right under the master. its like a 2 prong plug. what is that for because i don't have a wire hooked up to that...
so bench bleed first while its off or should i do it while its on the jeep? the master cylinder and the brake booster were attached when i got it. so detach the master cylinder then bench-bleed? put it bak on the brake booster then put it all in the jeep. and hook up the lines? i have to bleed the brakes too?
Okay, so they were attached... that may make it somewhat easier, I would imagine... I think I would bench-bleed the master with the booster attached, as long as you can hook it up that way. That way you can bench-bleed it using the push-rod instead of a screwdriver. Do it in a vice, if you have one. Clamp it so it's level and bleed it, so you get those last few air bubbles out. And I would bleed the entire system as well. Brake fluid is cheap you don't want to chance having air in the system... I would say that's the best way of doing it.
While i was looking at all the brake related components. i saw that this was unplugged (the red plug). does it matter if it is plugged in or not? ...
Under the switch is a shuttle valve that will operate if either the front or the rear brake fluid circuits lose pressure. It's part of the dual circuit braking system.
There should be a warning lamp on the dash that will light up if the switch is operated due to a pressure issue. To test, just bridge the contacts, turn on the ignition and look at the dash .. does a lamp come on. If not, then maybe the lamp has blown.
By default the lamp should never come on (unless it's part of the self diagnostics on start up .. I can't remember)
[I]Who's[/I] in front ?