justice
Roll Me Over
Reged: 02/06/00
Posts: 3163
Loc: Coastal N Carolina, USA
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Today I had a total front brake failure (89 SWB) on way to the junkyard. The pedal went to the floor and luckily the rear brakes still locked and I was able to steer away from a rear end collision. I pulled over and saw brake fluid on the inside of the driver side front wheel. I clamped down the line on that side with a pair of vice grips and limped it home on the back roads.
When I got home I tore it down and found that the outer pad was missing and must have shot out during braking over extending the caliper pistons and thus leaking out the fluid.
When I did the swap to gen 2 calipers and pads about 3 years or so ago, I re-used the Gen 1 disks (rotors), which were thinner than the gen 2 disks. I had the gen 2 disks in the garage, but just never got around to installing them...Lesson learned. When the pads are near the end of their life there is not enough buffer in tolerance to allow for the caliper brackets to grip the pads..Not too sure what the specs were on the gen 1 rotors either, they may or may have not been turned down in the past and most likely it was a combination of the three, wrong thickness rotors+worn pads+worn rotors=Bad news...Lucky I didnt hurt anyone or myself. I know it was Kevin C I think that warned of this in the the swap thread...theory proven..
CONCLUSION: If you have done this swap, do it right and swap in the proper Rotors.
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99 Gen 2.5, fixing, awaiting build
89 SWB- 33's, ARB Front locker, SR rear locker/axle, SR F brakes, winch, WST Offroad Armor all Around, 2.85 Aussie T-case Gears
Sold: (2) 95 SR's, 86 SWB, 90LWB, 91 LWB
-Can Change a timing belt in my sleep..
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fasteddy
Web Wheeler
Reged: 01/30/01
Posts: 12707
Loc: Flat Creek, GA
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Good catch. It's worse than that. I've had on several occasions the fun of having the pads do the same on stock brakes. I think a lot of the aftermarket pads are using thinner backing plates, and thus the almost worn out thickness of the pads is less than the pad ear slot in the caliper's depth, and the pad spits out on the ground. In your case, the piston had enough travel room to exit it's bore, too. Mine stayed in, and I got to stop on the head of the piston, once I panic pumped the pedal a couple of spasms. This is how I found out that the 95sr had plastic pistons...
I now check the pad thickness religiously, and I don't turn rotors any more. New ones are too cheap.
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"If you can't be a good influence, don't worry, you can still be a horrid example."
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Mudraider
Body Damage is Cool
Reged: 12/16/07
Posts: 1354
Loc: Orange Park, FL
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Having just done this see this thread name had me worried for a second. Somehow I guess I followed the recommendations and did the whole swap. Glad no one was hurt.
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87 Raider,3.5 soon,, 35's w/ a 4" BL,
bumpers, sliders, OME 2" lift Dakar springs, 98 Air locker, disc brake rear end, Gen 2 front brakes, plh manual hubs,
88 SWB-2.6/5spd, 2" BL, bumpers and sliders, Starion shift knob
89 SWB, V-6 6SPD, OME Shocks, 15X10 w/33's, 2"BL
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hazy_daze
Roll Me Over
Reged: 05/22/07
Posts: 4609
Loc: Athens, Georgia
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Glad you caught it and noone was injured. 
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Just another idiot...
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mxmikie
Body Damage is Cool
Reged: 04/12/06
Posts: 1081
Loc: Bouse az
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Quote:
Today I had a total front brake failure (89 SWB) on way to the junkyard. The pedal went to the floor and luckily the rear brakes still locked and I was able to steer away from a rear end collision. I pulled over and saw brake fluid on the inside of the driver side front wheel. I clamped down the line on that side with a pair of vice grips and limped it home on the back roads.
When I got home I tore it down and found that the outer pad was missing and must have shot out during braking over extending the caliper pistons and thus leaking out the fluid.
When I did the swap to gen 2 calipers and pads about 3 years or so ago, I re-used the Gen 1 disks (rotors), which were thinner than the gen 2 disks. I had the gen 2 disks in the garage, but just never got around to installing them...Lesson learned. When the pads are near the end of their life there is not enough buffer in tolerance to allow for the caliper brackets to grip the pads..Not too sure what the specs were on the gen 1 rotors either, they may or may have not been turned down in the past and most likely it was a combination of the three, wrong thickness rotors+worn pads+worn rotors=Bad news...Lucky I didnt hurt anyone or myself. I know it was Kevin C I think that warned of this in the the swap thread...theory proven..
CONCLUSION: If you have done this swap, do it right and swap in the proper Rotors.
a good case of never enough time to do it right but funny how you can always find time to do it over ........ or cut corners cut your own throat
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it dosent have to be surrounded by water to be an island
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OldColt
Roll Me Over
Reged: 09/19/06
Posts: 2599
Loc: East Wallyworld Vermont
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Scary thing to happen,
Keep in mind the Gen2 has two different rotor thickness available thus you have a choice of calipers for narrow or thick discs. I swapped the brakes on my Mighty Max and chose calipers from a Montero Sport, these are the thinner disc brakes. My discs were fine, I had a sticky guide pin and chose to upgrade the brakes rather than deal with stuck pins again.
The SR uses the thick disc therefore a wide caliper and to me is not suitable for retrofit unless you swap the wide disc as well.
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Cheers, Charlie
If It ain't broke, Modify it!
87 Montero turbo Converted back in 1989
95 Montero SR 3.8 DOHC First one?
Will a 94 Macrocab turbocharged with a 6 speed be next?
ffmsd.com
http://www.cardomain.com/id/Old-Colt
http://6g72rwd.forumcircle.com
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Kevin C
Trail Leader
Reged: 05/20/00
Posts: 6033
Loc: No where in particular
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Write up in the Archive that needs editing
Post that points out the possible problem - With rotor data.
Rotor Problem Post
Quote:
Using the thinner rotors ( factory 90 v6) wont hurt your pedal travel (initially), but it will put the pistons out further. As you get to the end of your brake pads the calipers may not work right since the pads and the pistons are too far out.
The best plan is to use the rotors and the calipers from the 95 as a set.
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Quote:
I updated the brake info thread with the V6 3.5 rotor VS the V6 3.0 rotor.
V6 3.5 Brake Rotor/Disc Initial Thickness (mm): 27 (1.063")
V6 3.0 Brake Rotor/Disc Initial Thickness (mm): 24.3 (.95")
V6 3.0 Maximum Discard Thickness (mm): 22.35 (.88")
Worst case is you have a 5 mm thinner rotor, that's with the rotor just cut and does not take into account wear.
I dont know exactly what having the piston and the pads out an extra .2" will do, but its not something you want to just take for granted and says its OK.
This is one the the key factors that determines how far rotors can be cut on a stock system. Remember the piston has to travel to account for wear on both pads. How will it work .2" further out when your at the end of your brake pads?
In the same thread Fast Eddy also pointed out the pads can drop out. Now we know for sure that it can happen.
Moderators, The brake swap FAQ post is archived and needs to be edited and updated.
Justice, glad that nothing worse happened.
Kevin
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KF6ZPL
Recreation Advocate
Reged: 02/15/00
Posts: 3951
Loc: Lakeside, CA
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Justice:
Glad to hear there were no injuries involved.
Everyone:
Thanks for the update info. I will see that the FAQ does get edited.
And, perhaps it does not need to be said, but...
A couple of points to keep in mind when dealing with vehicle mods and brakes.
1 - The steel brake lines have clamps to hold them in place. And, some steel brake lines have a coiled steel wire sleeve. That coiled steel wire sleeve does serve a purpose - it reduces vibration which reduces the chance of the steel line cracking where it bolts into the brake backing plate. IF you replace steel lines, try to salvage the steel wire sleeve and ensure that ALL clamps are in place. I recommend using loc-tite to ensure the bolts do not vibrate loose.
2 - Anytime you have rubber lines, replace them on a periodic basis. Rubber casing will deteriorate over time due to heat, internal pressure and weather exposure.
Lessons from the BTDT department...
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John Stewart
Editor - 4x4Wire.com
4x4Voice
Board Member BlueRibbon Coalition
CA4WDC Resources Consultant
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off-roader
Mitsubishi Forum Moderator
Reged: 01/16/00
Posts: 15507
Loc: Bay Area, CA
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Very scary Justice. Glad all's well. I've added a note about this and linked this thread in Grasscat's thread.
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Off Roader
96SR (3.15:1 xcase, 35's), 89 V6 SWB (33's)
96SR Build Up Thread
Old web page
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Kevin C
Trail Leader
Reged: 05/20/00
Posts: 6033
Loc: No where in particular
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Quote:
That coiled steel wire sleeve does serve a purpose
My understanding of the reason for wrapping the steel line is to protect the tubing from mechanical damage. That includes rocks, flat tires and wrenches.
Might be a good upgrade for people replacing their lines.
Totally agree on regular maintenance and inspecting parts.
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87 Dodge
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