OK, I just got my '94 (see previous post) and the brake light was on and the pedal goes a LONG way down. Stops fairly well if you can get used to the long pedal travel. Obviously I do not inted to drive it this way, but I did take if for a test drive and drive 20 miles home in the condition it is in. When I looked at it I figured there was a leak somewhere due to low fluid in rear res on master. Nope. I had my wife pumping the brakes like crazy with me on a creeper underneath and can locate no leaks. So I pull both rear drums thinking a cylinder must be leaking- rear brakes look mint, like someone just replaced them. While I was playing with them and my wife was in the Jeep I determined the back brakes are doing nothing. Nada, zip, zilch. No brakes at all. With pedal all the way down after pumping them both rear wheels spin free and easy. (there's your problem, right there!).
Maybe PO did brakes and crappy job of bleeding them or is the master toast?
Possibly the proportioning valve? How do I figure out what is wrong? First one is easy- bleed the brakes again and see if it helps (I sprayed the bleeder valves with PB Blaster but had no time to try and bleed them).
Something is setting off the Brake light though, so there is something not right. Could air in the system cause the pressure difference and make the light come on? It also could be the parking brake switch, I need to unplug it and make sure I still have the fault light.
The long pedal/large amount of displaced fluid (to the rear brakes) is most likely setting off the light. Once the issue is resolved the light will go out on it's own.
Check the shoe to drum adjustment as I suggested & if you feel energetic enough, make sure the new shoes are oriented properly with regard to "leading shoe" and the "trailing shoe" placement. This will maximize efficiency once you get things sorted out.
For reference, the trailing shoe uses the most amount of friction material, while the leading shoe has less material.
OK I think you guys were onto something- I manually adjusted the rears, then bled the rear lines with help from my wife and got a really firm high pedal with no creep. Once I started the Jeep though, the pedal went most of the way to the floor, but at least the brake light is out now. I have a lot more pedal than it did but I am still not happy with it. Do I have to bleed the brakes again or bleed with the engine running, or does it sound like my master needs replacing? I did not flush the old fluid out, and only bled them a bit b/c I could not find my brake bleed kit. I will pickup another one so I can catch the fluid and see when it comes out clear. Could it be just old, contaminated fluid in the lines?
I don't mind spending the money to fix it right, but I hate spending $$ on something if it isn't broke (more money for other improvements!).
Leading and trailing shoes were on correct, but were really far out of adjustment (a good 6 full turns on adjuster before they made light contact with drums.
Thanks again for all your help, JF rocks!
I will bleed all four brakes, as well as run enough BF through that I have fresh clean fluid throughout- I just was testing last night and I believe a good thourough brake bleed will solve my problems. If not I will do the master. I was in a rush last night because there was a storm coming- and completely off-topic the storm came and kicked our @$$- my next door neighbor's house got hit by lightning and caught on fire. Transformer for both our houses is toast and I will be without power for up to 3 days. :-(
Need to buy some oil lamps so I can wrench after dark! :-)
To add to their suggestions. Once you get it all back together run in reverse a few feet then jab the brakes off and on the brakes and then forward and jab the brakes off and on the brakes. Do this a few times to help set the adjustment for your rear brakes. I ususally get the adjustment fairly close then use this technique to set it the rest of the way. Has always worked great for me as my dad taught me.
(a) Drive vehicle and make one forward stop followed by one reverse stop.
(b) Repeat prcedure 8-10 times to actuate self adjuster componentes and equalize adjustment.
(c) Bring vehicle to complete standstill at each stop. Incomplete, rolling stops will NOT activate adjuster mechanism.
I will be doing this as well, once I have it all back together. I have to decide which of the 3 sets of tires I have I am going to put back on: The stockers (probably not!), the Goodyear Authority 31X10.5 or the Cooper Discoverys @ 265/75/15 (30.5" tire, but actually are within a couple mm of the same size as the 31s).
HaHa I never even look in the book for that one or knew it was in a manual. Just thought it was something my dad taught me from his dad. hmm kinda took the air outta my balloon. lol it's all good. Just figured it was an unwritten truth to drum brakes that fathers past down to their kids.
To add to their suggestions. Once you get it all back together run in reverse a few feet then jab the brakes off and on the brakes and then forward and jab the brakes off and on the brakes. Do this a few times to help set the adjustment for your rear brakes.