Rear disc proportioning issue, insite please (1 Viewer)

[belaw]

Are the 4runner calipers a direct bolt-on replacement? Do you know what year 4runner I should ask for when I go to the junkyard?

Yes, they are a direct bolt-in, although you will also need to use vented rotors from a FJ60 (which also helps improve braking as Mark pointed out). Also, you may have to grind the ribs on the calipers a bit, depending on your wheels.

I believe that the calipers you want are from a 1992-1996 IFS 4-Runner. These are the ones that have 4 large, equally sized pistons. If you're interested let me know, I have an extra set I picked up at a pick-and-pull but never used.

Just do a search for "4runner calipers" and you should find some good information.

 

[MtnTrucker]

PM sent

 

[scotia]

Well its been a week or two since I started this thread and have read up on a bunch of info but.....I have taken my rear line loose from the master cyl and have removed the larger 17mm nut that threads into the master and still see no FACTORY residual valve. No spring or disc valve. Just a copper sealing washer. Was the residual valve built into that seperate FACTORY prop valve like the one pictures in the above post? A picture would be great.

 

[scotia]

I just got off the phone with Wilwood just to make sure that my Wilwood prop valve and resid valve were plumbed properly meaning.........from the master cylinder is the redisual then the prop valve. When I asked why, they said that it is the best way to runs the parts. So I know I have that correct on the truck. Now back to that Factory resid valve.....where the heck is it?

Excuse the pic but is the Factory resid valve under the circled cap on the prop valve?

 

[Mark W]

Again, the OEM residual valve is in the MC. It is part of the MC assembly and not a separate part or a part of the OEM proportioning valve. It is in the fitting that the rear brakeline connects to. If it is not there.... someone has removed it in the past... or you have an aftermarket replacement M/C from a company with poor quality control (seen it).

Just a FWIW... the OEM residual valve often fails to hold pressure anyway.


Mark...

 

[scotia]

There is not even enough room behind this fitting for one. This is the fitting that I have.

 

[scotia]

ttt...anyone? And with all these views.

 

[pbgbottle]

not sure if you read this thread but there are some pics posted in this thread showing the residual valves /master post #18,30,43 etc.

https://forum.ih8mud.com/40-55-series-tech/185237-serious-safety-issue-master-cylinder-mods.html

 

[Poser]

ttt...anyone? And with all these views.

You are not going to get, and you really do not want the front wheels to skid in a panic-stop with stock front brake components, master cylinder, and using larger tires. Skidding tires do not have traction and if you do not have traction, you do not have directional control.




Because of inertia you get weight transfer from the rear of the vehicle to the front, hence why when you do panic-stop, the front suspension will compress slightly while the rear will unload and permit the rear brakes to lock up; disc or drum in the rear does not make a difference.


The stock Toyota proportioning valve located below the master cylinder does a fair job at best of preventing the rear brakes from locking up. I have installed everything new into a 1977 40 series running 33-inch tires; disc front drum rear. The rear drums would still lock up. When backing up fast on a dirt road, the fronts would lock up, but would not ever lock up under a panic-stop going forward.

The above is also true on a 12-82 40 series with the later style rear drum brake configuration as well. At the customer’s request, I backed the brake shoe adjusters off in an attempt to prevent the rear brakes from locking up when aggressively braking. This only proved to provide more pedal travel before locking the rear brakes up.



How about a few more pictures, perhaps a little larger, from a real digital camera that can show some detail of how you have things plumbed, and where things are mounted?



Where is your truck located?

 

[Mark W]

Not sure what else I can tell you Scotia. Spelled it out pretty completely I thought.


Mark...