FAIL brakes - what do?

[RobertISaar]

ok... i'll try and start from the begining:

 

lately, we would occasionally hear one of the rear brakes grinding to a stop, but it was fairly rare, so it wasn't reallyan issue. so since we're not planning on going anywhere for a few days, i decided i wanted to pull off the left rear wheel since after a long drive, that was the only wheel that wasn't at least warm to the touch.

 

so, after breaking loose the 200+ ft-lb torque that some ape managed on the lugnuts(electric impact FTW), i finally got around to jacking up the car, so threw the hydraulic jack under the rear end and jacked up on that pad that sticks out from the center of the car, no more problems yet...

 

then i get the wheel off... no surprise, the rotor is gouged to fuck and the outer pad is held in only by the little posts that stick out through holes in the caliper. the rotor itself is fairly thick, but both pads were ground to nothing. so then i go on to deal with the rest of it.

 

 

now, i pulled off a spring that's not even in this diagram, and i don't quite remember the orientation or location of it, so i left it off during reassembly. then i moved onto the return spring, easy enough with a pair of vice-grips. then it was time to pull the e-brake cable off of it's lever, not as easy, but still managed it.

 

then i pulled the bracket for the e-brake, simple enough, i believe all it was held on by was a T40 bolt? then the lever itself for the e-brake was supposed to come off, it was stuck to the actuator screw, but some light hammer tapping got it off. now, i do NOT remember seeing any kind of seal either on the screw or stuck to the lever, and i looked in the area anyway, but nothing was found.

 

pulled the caliper assembly off after fighting with the rotor a bit and got to the point of needing to retract the piston... well, i damaged a c-clamp trying to go about the way i've dealt with any other disk brake system, and then i stuck a socket on top of the piston and hammered like hell, still nothing... then i went and looked at the back of the caliper at the actuator screw(before i realized what it actually did or was called), and tried loosening it...

 

and it retracted into the caliper, so i'm thinking sweet, progress, so i keep twisting my thumb on the top of the screw and get it to sink pretty far in, then i grab the c-clamp again and stick the fixed end over the hole where the actuator screw stuck out and the business end made contact with the piston. i lightly screwed it down, and didn't see much movement, but some, so i grabbed a pair of pliers and started twisting with a little bit of pressure from the c-clamp. the piston went down, oddly enough, so then i just continued cranking on the c-clamp, and the piston kept going until the top of the screw made contact with the fixed end of the c-clamp, so i just threaded the screw down some more and kept running the c-clamp and got the piston most/all of the way down.

 

at that point, i yanked the inside pad off and saw a little yellow grommet(what it looked like anyway when it was retardedly dark outside) in the center of the piston, so i pulled it off, not knowing what it did, and immediately lost it. according to the diagram, it's a 2-way check valve(whatever the hell that means:think:).

 

so, thinking i have everything more or less figured out, and confirming that the caliper isn't stuck(at least it isn't now, if it was before it wouldn't surprise me), i decided to throw it all back together, more or less in the reverse of disassembly. now when i got to dealing with the e-brake lever, i decided to just bolt everything up and see how it reacts since apparently i was missing a seal for it. had the wife pump the brakes while looking for leaks, and eventually traced it back to the actuator screw, so i tightened it just a LITTLE bit at a time, and got to the point of where it was JUST barely losing fluid with every press, so i went for another short amount of torque, then half my body decided to do the worm and the socket slipped off of the screw, taking the edges of the head along with it...

 

so, i grabbed vice-grips, loosed it, and then threw a torque wrench on to see just how far it goes without slipping..... ~30ft-lb, which is like 5 under spec IIRC, and now it leaks like fucking crazy whenever the e-brake is not applied(even then, it still leaks, just slower.

 

after that, i still put the rest of it back together, and now the brakes are almost 100%teh suck. if you slowly and steadily apply the brakes, you get nothing at all until at the end of travel, but if you absolutely stomp on them, both fronts will lockup(don't know about the rears) and then slowly lose any effect. the e-brake now works somewhat normally, before, if i jumped on it, the car dove to the right every time, now the tires lockup during the second pump and doesn't shoot in either direction.

 

so, from what i can tell, it seems that i'm getting a leak due to the shaft seal and the mating surface inside of the caliper? i'd also like to know the importance of that check valve and lever seal(even though the lever doesn't look to be the issue, since even with no lever installed, it still leaks). and why i seem to have an extra spring....

 

i also managed to strip the head off of the bleeder valve, so now the only thing that can remove/tighten it is vice-grips.

 

so.... what do?

 

1. do it right and (insert proper instructions here)

2. junkyard caliper(s)

3. parts store calipers(or possibly a rebuild kit?)

4. look into this 94-up upgrade that gets mentioned(parts list and expected costs would be good!)

5. find cliff, fake death for insurance money, buy more rotbox W's under the name of Rusty Shackleford

6. send it on it's final voyage

[tornado_735]

1.) and replace with new if you can afford it.

 

If you can't afford it, then go with 5.

[RobertISaar]

what about the second half of #1(what i did wrong)?

[Crazy K]

4 via 2... as I have done about 4 times now with good results.

[RobertISaar]

thread with details?

[Crazy K]

You need: (from 94+)

Rear calipers

rear rotors

rear caliper brackets

rear pads

rear caliper bolts (shorter)

springy things that hold pads in place.

new banjo bolt rings.

 

the ideal parts will have evenly worn pads and when you unbolt the caliper it comes free of the bracket with the top bolt. I used to find about 90% were good used, but the number has declined to about 40% now.... shows people don't get em serviced well...

 

 

to do:

remove wheels and raise car on jackstands.

remove old 93- calipers.

remove dust shield and discard... 94 doesn't use em.

 

install 94+ parts (spindles are identical, so this is a quick bolt off bolt on procedure)

twist rubber brake lines just slightly and attach.

 

parking brake cable is different, but you can force the passenger side it kinda loosely(though you do need to route it behind the gas tank instead of in front), and attach the driver's side one and lock it in place with a ziptie. Alternatively, you could attach 1994+ brake cables to the car....

Edited September 4, 2010 by Crazy K

[RobertISaar]

is caliper brackets another way of saying the knuckles? or is that the only name they go by(seems i'll be digging through alldata for references)? i'm almost a total suspension and brake parts newb...

 

and any gen1 W from 94-97 is the same? nothing got larger or thicker rotors, or anything weird like that?

 

i may be able to grab all of this fairly cheaply....

 

"when you unbolt the caliper it comes free of the bracket with the top bolt"

 

is this implying that you should be able to rotate the caliper with only the top bolt removed?

[mra32]

is caliper brackets another way of saying the knuckles? or is that the only name they go by(seems i'll be digging through alldata for references)?

 

Calipers are essentially 2 main pieces. The caliper part where all the hydraulic shit goes on and then the caliper bracket which is the part that holds the sliders that the hydraulic part slide on. Makes sense? To remove the caliper, most people just remove the bolts that affix the bracket to the knuckle. Note that many junkyards will also consider this 2 different pieces and will charge for each.

 

I definitely say do the 94+ upgrade with junkyard parts

[mra32]

is caliper brackets another way of saying the knuckles? or is that the only name they go by(seems i'll be digging through alldata for references)?

 

Calipers are essentially 2 main pieces. The caliper part where all the hydraulic shit goes on and then the caliper bracket which is the part that holds the sliders that the hydraulic part slide on. Makes sense? To remove the caliper, most people just remove the bolts that affix the bracket to the knuckle. Note that many junkyards will also consider this 2 different pieces and will charge for each.

 

I definitely say do the 94+ upgrade with junkyard parts

[Crazy K]

Essentially... 94+ uses a bracket with the caliper. 93- the caliper is built to perform the function of the bracket. Basically a one part design was replaced with a higher quality two part design by GM, and both will bolt to the same spindle/knuckle...

[White93z34]

http://www.w-body.com/showthread.php/46803-Chris-TGP-Project-Lets-try-this-again/page8

[RobertISaar]

ahh, the info and pics are much help... now i just need to wait for the holiday to be over to grab parts for cheap.

[RobertISaar]

hmm..... the caliper rebuild kits would cost me less than $20..... but none of them have new actuator screws, so it seems i'm getting "new" calipers, and since the yard will charge me the same for a 88-93 set as a 94-96, i see no reason not to grab the newer style.

[White93z34]

Calipers cost me $20 each with all the hardware at the pick n pull

 

Rotors were on clearance on rock auto for $8 each, raybestos pro pads were about $20 Brake upgrade on the cheap. I just had to bend up the factory hoses to fit better.

[RobertISaar]

yar, i've looked up the stuff we plan on more or less immediately replacing, pads were $20 for lifetimes at advance and autozone, rotors also came out to less than $40 shipped for the pair from rockauto.

[RobertISaar]

ok, tomorrow, i should be able to make it to the yard and grab everything i need, going to have to basically force the e-brake on for the caliper that leaks to try and keep some fluid and pedal with it, no big loss though.

 

but what are banjo bolt rings? i assume the banjo bolt itself is the bolt that the brake fluid runs through after the rubber line? are they basically washers?

[birdman]

Never heard them called rings, but there are 2 copper crush washers that go on either side of the brake line end. One between caliper and the end of the line, and one between the end of the line and the banjo bolt.

[RobertISaar]

that's what i'm thinking is refered to as "rings".

 

 

autozone seems to have a hose/washer combo, but i'm not seeing just the washers...

[mra32]

vato zone // poop boys should have a package with an assortment in the "ZOMG HALP!!1" section. Its not the best, but its the solution they offered me when i asked for like 8 of them.

[RobertISaar]

an assortment huh? better than nothing...

[birdman]

Your not supposed to but as long as your washers are not totally hosed you can reuse them if need be. Being copper they will smash down and re-seal but if you can get new ones i would.

[RobertISaar]

with my luck, they may or may not work again.... eh, it's easy enough to get to when the wheels are off, i'll reuse the old ones then if need be, get new ones.

[birdman]

Sucks your not closer, i must have 10 extras laying around.

[RobertISaar]

from the looks of it, i'll have plenty of my own extras.

[Crazy K]

to re-use the rings I have always wet sanded them smooth prior to being re-used. I have no fear of doing this on my own car, but last car i did for someone else I said we need to get new washers.... the dealer had the only exact fit size washers, and the set of 4 was about the same price as all the regular part store's ones, but the part store ones were all too loose....