BJ70 Brakes are Weak

[aamiggia]

I've searched the forum and come up with the following:

- Adjust LSVP
- test / check vacuum
- check for leaks
- use quality parts for replacement
- 4runner calipers and master cylinder will fit a BJ70

Here is my question.

Are 4runner calipers bigger and better then BJ70/60 front calipers? or are they just easier to source?

Is the 4runner/T100/Tacoma master cylinder bigger / better? or is it just easier to source.

Thanks,
Alex

 

[Glenn-BJ74]

A friend of my mine installed the larger calipers and booster in his BJ74 and he said "it did make not much difference". Based on his experience I abandoned that idea and as an alternative I installed high quality components -- the Australian DBA 4X4 Survival rotors (slotted not drilled), PBR pads and replaced all my brake lines (old lines can flex) and my brakes work very well now - even down long steep mountainous descents loaded at 6,000 lbs.
But first make sure your rear brakes are clean, working and adjusted. If the adjusters are working you back-up, apply the brakes and drive forward and apply the brakes - do that a few times and your rear brakes should come up. Poorly adjusted rear brakes are often the first cause of poor braking .

 

[Radd Cruisers]

I've been down this road as well, and the BJ7x series should have decent brakes. But, there does seem to be some variability between how some individual vehicles perform... some being very good, and others being quite weak.

The later calipers that you're talking about have two larger pistons on each side rather than a smaller and larger piston. It's probably a good idea to use the larger diameter master with the larger caliper pistons.

The downside is that with a larger master and a larger piston, you're going to have somewhat more pedal effort for the same braking force.

What I did:

- New Mountain rotors - these are made in Japan and work really well.
- New PBR Metal Master pads -
- New brake hoses throughout. They do not need to be fancy ones, just good new ones. As the hoses get older they flex and expand more - this leads to a soft pedal and poor braking performance.
- Thoroughly flush all of your braking system with new fluid and re-flush at least every two years to keep moisture out of the system.

** Make absolutely sure you have set up your rear brakes properly **
lots of pedal feel will be lost here if you have not set up the parking brake cables and shoes to drums properly. If you have an LSPV, then set that properly for your lift height.


--> If you're looking for more than that:

- Install the later calipers - slightly larger pad, and pistons are the larger ones (later 4 runner units, for example)
- Install an 80 series brake master (the aluminum one). We can get genuine Aisin for a good price.
- Install a dual diaphragm booster.


~John

 

[Radd Cruisers]

One more note:

make sure that your wheel bearings are properly adjusted or you will get "caliper kickback" from the brake disc running off square to the pads & calipers.

This is a fairly common cause of not so good braking and poor pedal feel.


~john

 

[roscoFJ73]

A lot of pedal feel is obtained by paying close attention to the rear brakes shoes .They need to be kept clean and fully adjusted with all the springs in good condition.