1st gen 4Runner v6 Brake Upgrade Question (1 Viewer)

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I just helped with a crazy brake redo on my buddys 1986 22R 4cyl lifted yota truck.
We went with a 1996 T100 dual booster and master cyl from a clean junkyard donor (eventually).

The reason for the brake redo was a bad original 86 single booster plus other misc. junk.
We got another bad booster from a parts truck of his.....same kind of failure mode where pedal dropped to the floor easily.
Not the hard pedal you normally get!
One big symptom was the engine dying/leaning out massively when he hit the brake pedal.

Then a bad "new" master cyl from Autozone right out of the box was next.
Total confusing suckage for a couple days. Much wasted brake fluid.

Once we got the T100 booster and matching master in there all was fixed. Nice brakes that can lock the 33" tires on pavement.
We kept the stock 86 front calipers and used Autozone 1986 4cyl replacement rear wheel cylinders (kinda gross).

He called it "Going to Toyota brake school for a week".

Anyway...

I just rebuilt the OEM Aisin rear wheel cylinders on my 1988 4Runner.
It is super easy when they are rust free and all boots are intact (New Mexico truck).
I used 1000 grit sandpaper to gently clean all internal parts and the bores, then blasted it all out with CRC LectraMotive cleaner.
Lubed all parts with thin coat of white lithium per factory service manual.
Perfect function no leaks. Autozone rear cylinders look trashy compared to the original parts on the truck.

I'd learn to rebuild the front calipers/rear cylinders on these trucks.
If somebody replaced the parts with reman parts, I'd find clean junkyard parts to rebuild.
All the reman stuff looks crappy to me. Plus reman calipers etc. are starting to get pricey.

There is video of a barefoot Aussie girl rebuilding Landcruiser 60 calipers in the dirt on YT.
If she can do it...you can too.

 
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Joined
Jul 7, 2014
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Hey thanks for the reply and motivation! Haha
As of now I'm deciding if I should rebuild the calipers myself or buy toyota remanufacted ones (found out they do have them), would save about $200 if I rebuild them myself. After reading a few threads, rebuilding the calipers doesn't seem like the biggest job. Curious if there is a seal in between the two halves of the caliper? Most rebuilds I have seen keep the calipers halves together and then replace the pistons and boots ect. Here are some helpful links I've looked at
Brake Caliper Rebuild
4th Gen Front brake caliper rebuild for stuck piston - Toyota 4Runner Forum - Largest 4Runner Forum
http://www.wilwood.com/Pdf/HowToStories/Caliper_Rebuild.pdf

Lastly, here are some brembos that have an oring between the caliper halves. Do toyota calipers have this?
Brembo Caliper Rebuild Subaru STi: - Subaru Idiots
 

ntsqd

technerd
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Without an external cross-over tube, which these calipers do not have, there will have to be a seal between the two caliper half bodies.
 
Joined
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Ok, I figured. Not sure if it is included in the piston rebuild kit so I'll have to do a little more research.
Thanks
 

KLF

Frame waxer
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There are little donut gaskets between the calipers, but they are not in the rebuild kits. Technically you're not supposed to split the calipers, which is why the torque values for the 4 bolts holding them together are not provided anywhere.
 
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The small O rings between caliper halves do come in some rebuild kits. Centric brand has them included.

1987 V6 caliper kit:
More Information for CENTRIC 14344031

Some more bits of info. I just rebuilt my 1989 4Runner stock 4cyl calipers with those Centric kits.
My bolts holding the caliper halves were super tight so I didn't bother to split the halves.
Would have made it much easier to clean the bores but whatever.

I carefully used vice grips to rotate and pull the pistons out by their edge lip only (part that contacts the pads). No compressed air required if the calipers are old and square O ring is worn. See Aussie girl video...

The 4cyl calipers have 2 different size pistons, large and small.
Putting the boots and retaining wire on the large pistons is easy, but the boots on the small piston will drive you crazy.
The boot will not stay attached and kept rolling back up.

From here on out I would only go with V6 calipers as all 4 pistons are the same size.
Not worth the minor struggle to do the 4cyl calipers.

Tundra caliper rebuild video. Note the same size pistons.
Also, he shows the gap in the retaining ring ends when installed.
The Centric kit I used had correct gap on the large pistons, but gap on smaller piston boot retaining ring was wrong. I had to file the ends to make the wire retainer "grab" the boot better. Another reason to stick with rebuilding V6 calipers.

 
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ntsqd

technerd
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In use those bolts are tensilely loaded. The install torque has to be high enough to generate a tensile loading in them such that the application of even panic-stop hydraulic pressure doesn't load them anywhere near what they already are loaded to. This keeps fatigue failing the bolts from happening.

I wouldn't separate the bodies unless absolutely necessary, and if that did happen I'd replace those bolts with an equal or higher grade bolt.
 

KLF

Frame waxer
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I should have been more specific, the donut seals don't come in the OEM seal kits, which is the only thing I would ever use.

Easy way to get the pistons out of the calipers: leave the caliper installed, pull the pins and yank out the pads. Stomp on the brake pedal. Keep an eye on the master cylinder as you pump on the pedal, the hydraulics will push out even the most seized pistons. The rotor will keep them from falling out and making a big drippy mess.

CalipersBefore.jpg
 
Joined
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Thanks for the info! I saw that youtube video before and that convinced me I could rebuild the calipers myself. I was asking about the o ring as I figured it should be replaced during a caliper rebuild. However after doing some more reading, I realized like others have said that it's probably not a good idea to break apart the calipers when there is no toque info. Knowing Toyota, I'm sure the o rings inside the calipers are manufactured to last.

Now I just need to order the rebuild kits..
 

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