Brake swap: Lessons learned (1 Viewer)

[Dirtys87]

Hi all. Once again, thanks to this forum, I was able to finish another upgrade to my Beast. Quick intro, FJ60 with 155K miles, stock 2F, '92 4runner M/C, SOA (stock springs with AALs), 37" Michelin XZLs, Ford bucket seats, Ford Contour fan, Hi-steer and a fire extinguisher.
To start, found a pair of '92 4runner front calipers from a donor truck with 90k miles on it (courtesy of my local pick-a-part $45 each). Tools used for the mod, common automotive hand tools, disc grinder, a few rags, brake bleeder and a can of brake cleaner.
Started with the passenger side; jacked her up, removed old caliper, removed the hardline to the caliper, ground of about a 3/4" wedge-shaped pieces from both ends of the dust shield. I did without dismantling the shield itself...because I'm cool like that . Cleaned the disc after a thorough inspection (I know.... you're supposed to machine these discs when you do a pad swap. Didn't do it because I had a wife and three kids waiting to go to the mall). Loaded up the donor caliper ( semi-metallic pads from Autozone- $38), and installed it back on with about a 1/4" gap between the caliper and the dust shield. Re-connected the brake line. Moved on to the driver side. Pretty straight forward. Did the exact same thing as the passenger side except I had to grind off the tab on the outboard pad because it was touching the disc hub by a hairline. Now that I think of it, it probably would have been easier to swap the pads out than to grind it off (lesson learned). Moving on. Put everything back together and started to bleed the system.
I used the Valvoline full synthetic Dot 3 &4 compatible fluid. BAD IDEA!!!! After bleeding the system, my in-cab brake light stayed on. I figured I introduced air into the M/C. SO I gave it a love tap to move the bubbles out. Nohting! So I figured the M/C was probably used to just the regular type of brake fluid so I drained and re-bled the system and presto! Prestone Dot 3 worked great! No more light.
Impressions on the new calipers. They are great! I can't believe how sucky my old brakes were until this mod. Drove it around town and on the freeway. Quicker stopping time and distance! I was actually able to make the Beast do a nose dive when I slammed on my brakes. It might need a little brake travel adjustment but I think it's just me. Thanks again to the pros in this forum for giving me the strength and knowledge to carry on!!

 

[nicholastheczar]

I just bought some Firestone synthetic brake fluid yesterday from Vatozone but have not used it yet. I just rebuilt my front axle and swapped out the calipers with a new set from Napa for a 93 4 runner. I wonder if I'll have the same problem as you?

 

[Dirtys87]

I wanted to give my Beast treat with the full synthetic brake fluid but just ended up wasting seven bucks. Not a whole lot but a pain to re-bleed the system. It's up to you. Good luck.

 

[chichiflys]

Dirty,
I noticed you already had the '92 4-runner M/C - did you have any issues with that setup, that is, the 92 M/C and stock calipers? I suppose you didn't notice any better braking action and that's why you went ahead and changed the calipers to the 4-runners as well right?

Marc

 

[Dirtys87]

Hey Marc, sorry for the late response- I'm on vacation. The only reason I swapped to a 4runner M/C was because my original M/C was on it's way out. Double sometimes triple pumping to get a bite from it. So the brakes were much nicer after the swap. More positive feel to it instead of the spongy feel. The stock calipers worked fine after the swap. I just switched to bigger 4runner ones because i went from a 35" tire to a 37", I needed the extra stopping power.

 

[RredFJ40]

Hmm, the brake light only comes on when the brake fluid level drops below a certain point. Funny that your float wouldn't work with synthetic. Seems like the bouancy would remain the same. Maybe your fluid was too low after bleeding?

I have an FJ80 M/C with stock calipers and it works fine. I have the 4rnr calipers just have to prep them and find time to get them on.

 

[Dirtys87]

Yeah Rred, I tried to mess with this synthetic stuff so I can leave it in the system. I tapped the M/C reservoir a little to move the bubbles around but no dice. The 4runner M/C had a bluish tint to the plastic so you could really tell where the fluid level was. Maybe I have a somewhat defective float? Maybe... Good luck on those calipers, it's a great mod. The memory of all of those people I almost rear-ended because of weak brakes are all but a memory... hehehehe

 

[Moby]

I've got TLC4x4's SSBC brake calipers, dba pads and slotted rotors. I used Valvoline's 3/4 synthetic. On a very long very steep downhill I boiled the fluid (caveat - I probably didn't completely get all of the old fluid out). I will be moving to "super blue racing" shortly. My friends that race their Porsches at the track swear by it. http://www.raceshopper.com/ate_brake_fluid.shtml You can get it in blue or standard and alternate so you can tell when you get new fluid all the way through the caliper.

 

[mtb_rider]

Hmm, the brake light only comes on when the brake fluid level drops below a certain point. Funny that your float wouldn't work with synthetic. Seems like the bouancy would remain the same. Maybe your fluid was too low after bleeding?

I have an FJ80 M/C with stock calipers and it works fine. I have the 4rnr calipers just have to prep them and find time to get them on.

Synthetic fluids, of any sort, are molecularly (sp?) smaller, and usually less dense (that is why leaky seals leak worse with syn. fluids than with dino), so the float may not float as well in the synthetic fluid. I have never used synthetic brake fluid, but this is what I know of synthetic oils in general.

 

[svo_jon]

Brake fluid is not pertolium based (dino), if it were it would reck the rubber parts/seals of the brake system over time.
Jonathan