mdelorie Posted April 14, 2007 Report Share Posted April 14, 2007 I had an interesting conversation with a parts guy today who pointed out a few things to me that I didn't know, hoping you guys could maybe weigh in on a few of them. 1) Don't machine solid rotors (ie. the rears.) The reason for this is that removing material from them causes them to dissipate heat less efficiently, and also can cause uneven pad wear due to the sliders being extended unevenly and beyond their designed range. 2) You don't need a tool to push the piston back in on a rear piston. I tried this last summer and wound up breaking a clamp, even with the parking break lever removed. After telling the guy this he indicated that the caliper would probably be toast as the bore and piston would be warped if this were the case. I managed to rebuild the caliper in question, but have noticed pretty poor performance from it since then. That said, would I be better off just buying new calipers? They're ridiculously expensive ($138 CAD each), and on top of new pads and discs this would end up being a 500 dollar job. A rebuild kit is a cheaper option, but if the metal parts are warped, that's kind of useless. Are these calipers known for warping? Thanks! Quote Link to comment Share on other sites More sharing options...
Q-Ball Posted April 14, 2007 Report Share Posted April 14, 2007 Goto a yard and upgrade to the 94+ rear brakes. http://www.w-body.com/upgrades/brakes-rearcalipers94.html The ones in ours are prone to seize up quite easily. Quote Link to comment Share on other sites More sharing options...
mdelorie Posted April 14, 2007 Author Report Share Posted April 14, 2007 I would, but I'm not willing to give up my parking brake. Quote Link to comment Share on other sites More sharing options...
MonteCarloDude Posted April 14, 2007 Report Share Posted April 14, 2007 i don't think you have to. Quote Link to comment Share on other sites More sharing options...
1990lumina Posted April 14, 2007 Report Share Posted April 14, 2007 Just finished replacing the rear calipers, rotors, pads, and pressure control valve on my sister's Taurus, was over $500 in parts alone... I think Crazy K found a way to do the 94+ brake upgrade and keep the parking brake! Quote Link to comment Share on other sites More sharing options...
White93z34 Posted April 14, 2007 Report Share Posted April 14, 2007 Just finished replacing the rear calipers, rotors, pads, and pressure control valve on my sister's Taurus, was over $500 in parts alone... I think White93z34 found a way to do the 94+ brake upgrade and keep the parking brake! in my humble opinion, and after replacing no less then 10 failed callipers (on my own car!) over the past 3 years, i can honestly say, the old stuff simply is not worth dumping money into. it isan't bad to get the parking brake working at all, you just have to drill some spot welds out. remove the parking brake cables from the parts car, make sure to get all hardware that it uses. the bracket that the cables slide through needs to be drilled out of the frame of the car, a sharp drill bit will do this in about 5 minutes do the same to your car, the old cables are a PITA to get out. then use some decent metal self taping bolts and a pilot hole or 2 to attatch the new bracket to your frame and install the cables in the way that they were on the parts car. Quote Link to comment Share on other sites More sharing options...
Q-Ball Posted April 15, 2007 Report Share Posted April 15, 2007 ya you can keep the parking brake. I'm going to do this soon as I get my car back. Quote Link to comment Share on other sites More sharing options...
CSI_MuNkY Posted April 15, 2007 Report Share Posted April 15, 2007 I wouldn't even waste my time rebuilding my calipers, although I only paid $60 each When I first got my car it needed a brake job, so I went at it and tried pressing the piston back in, I didn't know my weak little ass could ever bend a 10" C-clamp who knew? I don't see why you wouldn't be able to keep the parking brake.. of course I have no reason to look into the swap, so I'm oblivious... Jamie Quote Link to comment Share on other sites More sharing options...
Crazy K Posted April 15, 2007 Report Share Posted April 15, 2007 listen to Chris above. of course, he had a lift... my drill won;t fit beneath the car unless it is jacked the hell up. Quote Link to comment Share on other sites More sharing options...
Canada Posted April 16, 2007 Report Share Posted April 16, 2007 Never machine the rear rotors? Yes, you can. There is less metal, but there are thickness specs for the rotor.....all designed to give you a thick enough rotor so that the piston doesn't pop out of the caliper or so you still have enough rotor to build up heat with. Typically, you only remove 0.020" to 0.025" anyways. Why it being soild make a difference over a vented rotor? Quote Link to comment Share on other sites More sharing options...
pwmin Posted April 16, 2007 Report Share Posted April 16, 2007 goddamnit, not again you can use the existing cables and still have the newer brakes work. i wish i had the money to buy this shit, so i could do a writeup to sticky. Quote Link to comment Share on other sites More sharing options...
DOHCRagtopguy Posted April 16, 2007 Report Share Posted April 16, 2007 After many brake jobs on the wife's former Lumina and my Cutlass, I just bite the bullet and buy 2 loaded calipers from the store. Usually costs me around 120 bucks for a pair fully loaded. I refuse to waste my time fucking with that rear piston. POS design. You can do a light cut on the rear rotor, but not more. Just enough to bring it back to true. Hell, a new rotor costs about 25 bucks, so why bother. Total cost for a rear brake job for me is just under 200 bucks for parts. Not having to fuck with the rear caliper piston = priceless!! Quote Link to comment Share on other sites More sharing options...
White93z34 Posted April 18, 2007 Report Share Posted April 18, 2007 goddamnit, not again you can use the existing cables and still have the newer brakes work. i wish i had the money to buy this shit, so i could do a writeup to sticky. not to be a dick, but i would love to know HOW to use the old cables on the new calipers, i tried to make my old ones fit somehow, but in the end it was not all that much work, to just do it right and install the proper 94+ stuff. Quote Link to comment Share on other sites More sharing options...
94CutlassSLCoupe Posted April 18, 2007 Report Share Posted April 18, 2007 We swapped my dad's 90 cutlass to the 94+ rear parts...and kept a good working parking brake (the light bulb on the dash is out) and i drug the back tires pretty hard. All i had to do was get some calipers/brackets at the junkyard, new set of 1994 rotors, new rear pads, and i got the cut-off tool out to remove the mounting bracket from the 90 brake hose and also notch the aux spring brackets to fit the calipers since they are a little bit deeper. I then just bought a new set of 1994 parking brake cables from the adjuster/equalizer back and bolted everything right on. Works like a champ. Make sure you get the banjo bolts for the newer calipers and also the mounting bolts from the donor car. Go buy some new crush washers if you're re-using brake hoses like i did. These cars have such big DTV issues (and extreme front rotor wear) that i would never re-use rotors if you felt that they were highly worn or damaged AT ALL Quote Link to comment Share on other sites More sharing options...
RJansen658 Posted April 19, 2007 Report Share Posted April 19, 2007 1) Don't machine solid rotors (ie. the rears.) The reason for this is that removing material from them causes them to dissipate heat less efficiently, and also can cause uneven pad wear due to the sliders being extended unevenly and beyond their designed range. Never machine the rear rotors? Yes, you can. There is less metal, but there are thickness specs for the rotor.....all designed to give you a thick enough rotor so that the piston doesn't pop out of the caliper or so you still have enough rotor to build up heat with. Typically, you only remove 0.020" to 0.025" anyways. Why it being soild make a difference over a vented rotor? Canada is correct, there is a book that all brake shops have that show all the specs for machining rotors. The only problems there are with turning rear rotors, is vibration during the machining. Because brake lathes are rotational, solid rotors tend to vibrate A LOT when you turn them, and unless you set the lathe perfect it messes up the cut. But really, why turn a W body rear rotor? There is absolutely no point unless you are worried about saving $8. You can buy W rear rotors for $9.99 here, and it costs $6-8 to turn a rotor..... so by turning you save like $4-$8. Pointless. 2) You don't need a tool to push the piston back in on a rear piston. I tried this last summer and wound up breaking a clamp, even with the parking break lever removed. After telling the guy this he indicated that the caliper would probably be toast as the bore and piston would be warped if this were the case. I managed to rebuild the caliper in question, but have noticed pretty poor performance from it since then. I wouldn't even waste my time rebuilding my calipers, although I only paid $60 each When I first got my car it needed a brake job, so I went at it and tried pressing the piston back in, I didn't know my weak little ass could ever bend a 10" C-clamp who knew? I don't see why you wouldn't be able to keep the parking brake.. of course I have no reason to look into the swap, so I'm oblivious... Jamie Uh... Yea, you do need a tool for W rear brakes. Our rear calipers are self adjusting screw type calipers. You cannot simply push the piston back into the bore. There is a nylon screw that is operated by the parking brake lever that screws the piston out to self adjust the rear brakes. You may succeed at pushing the piston back into the bore by brute force, but if you do you have deystroyed the nylon screw that adjusts the caliper. Both the first gen and the 94+ brakes work in this manner. The correct way to do the rears is to lightly press in the piston, while turning the piston clockwise (although sometimes moderate force is required). There is a tool specifically designed for this, but usually I use a pair of needlenose pliers opened slightly with the tips in the grooves on the piston face. Both sides turn in clockwise, and adjust out counterclockwise. Just because the pistons don't go in easily doesn't mean they are seized. It can be hard to restart the screw on brakes that have been worn to long. When the pads on our rears get very low, with worn rotors, the pistons adjust all the way out and come to the ends of the threads. It can be difficult to push the piston in while turning it and trying to restart a screw you can't see. The best way to see if a rear W caliper is seized is to simply rotate its caliper with the grooves provided in the face. If it won't turn with moderate force it is seized. If it does turn its good, and just needs to be screwed in. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.