Brake Caliper Upgrade

[steveg]

Dave - Apologies. I followed the link and experienced the same facebook login. Forget that. Initially reached the page from a google search which evidently circumvented the facebook login.

Try the revised link in my above post.

[Westcoast M5]

Any thoughts on running without the backing plates? I am adding the AH 4 pot capiler to my BJ8 and there is no provision on the new calipers to attach the backing plate. Alternatively, I guess I would have to fabricate some kind of bracket, but any reason not to just delete them?

[John Turney]

The factory found that without the dust shields the brakes wore faster. I have a BN4 (originally with drum brakes) that I converted to discs. The disc pads might wear out faster, but we drive so little per year, the rubber parts will expire due to time first. So, don’t worry about it.

[Westcoast M5]

Thanks, I think I will skip them!

[steveg]

Thanks, I think I will skip them!

IMO, for BJ8s, dealing with the shields is easy. At the end of their instructions pdf, Moss has a full-size pattern for cutting the BJ8 shields to fit. My web gallery shows the additional work I did to brace the shields adjacent to the caliper, as well as brake pipe design.

See this for the big brake kit instructions:
https://mossmotors.com/media/instruc...6-725_INST.pdf


My improvments - see this and adjacent pics:
https://pbase.com/stevegerow/image/147633233

ShieldCutWithBraceBolts.JPG

[HealeyRick]

The factory found that without the dust shields the brakes wore faster. I have a BN4 (originally with drum brakes) that I converted to discs. The disc pads might wear out faster, but we drive so little per year, the rubber parts will expire due to time first. So, don’t worry about it.

I've also read that running without dust shields can cause the first stop when running in the rain to be a bit longer.

[John Turney]

I've also read that running without dust shields can cause the first stop when running in the rain to be a bit longer.

I didn't notice the stops in the thunderstorm near Mt. Shasta were any longer than normal. Then again, I couldn't see where I was going (no one else could either).

[steveg]

M5 - My reasoning on why you should use the shields:

1) The factory engineers and bean counters found them necessary. They would have preferred to leave them off and increase their profit margin.
2) You already own them, so the cost is negligible.

John - respectfully, you weren't in a position to try exactly the same stops with shields in place.

[HealeyRick]

Further progress today. I installed the .75" master cylinder from Pegasus per Steve's suggestion and the pedal travel is now perfect. Nice and high. Steve had asked me to shoot a picture of the clearance of the brake pipes for my BJ7, which has a different configuration than his car. Here's the shot. Clearance at full compression and steering lock is close, but doesn't require trimming as Steve's did. Might be a few days before I get to road test as I have some other non-related repairs to do.

IMG_0510.jpg

BTW. Checked Amazon and the right side Toyota caliper is out of stock although they have the left one. Other sources seem to have the same problem.: Centric Parts 142.44011 Posi Quiet Loaded Friction Caliper

[steveg]

Rick - is that the shadow, or does the bent pipe actually clear the shock tower edge by 1/8"? It looks like the pipe might extend under the flange of the shock tower, which would cause it to hit at full bump and lock.

The pipe and tube nut have to pass upward past the shock tower at full lock and bump.

[HealeyRick]

Steve,

This is at full bump and lock and the clearance is about 1/8". What I think I did differently than you is the fabrication and placement of my hard line to braided steel line bracket. I angled it down about 40 degrees which brings the connection below the shock tower.

[steveg]

Steve,

This is at full bump and lock and the clearance is about 1/8". What I think I did differently than you is the fabrication and placement of my hard line to braided steel line bracket. I angled it down about 40 degrees which brings the connection below the shock tower.

Sounds good.

PS - I got results by searching the caliper part number on eBay.

RockAuto: Toyota, 1985, 4runner, Brake - plenty there

[HealeyRick]

Got a chance for a short drive and braking is noticeably improved. Overall, a worthwhile improvement

[John Turney]

John - respectfully, you weren't in a position to try exactly the same stops with shields in place.

Well, I didn't run into the back end of Irene's BJ8, which does have them.

Since my conversion is on a BN4, I would have to buy shields and would probably have to modify them.

[Bob_Spidell]

FWIW, I got an email from DWM the other saying they've reduced shipping rates. I could only copy a portion of the email:

DWMShip.JPG

[steveg]

Well, I didn't run into the back end of Irene's BJ8, which does have them.

Since my conversion is on a BN4, I would have to buy shields and would probably have to modify them.

I wouldn't have bought them new either - not worth the $260 for a pair - but was able to get some rusty ones from whence I got my BJ8 swivel axles. I was arguing that they're easy to modify if one already owns them they should be included in the setup. They do have utility - that's why the factory included them.

[red57]

I've never had the shields and never had an issue in the rain - they don't seal so they don't keep the discs dry anyway, best they do is keep dirt & gravel off. In fact, I think they cool better without the shields - plus they add 'unsprung weight' .
Choice of pad material will have a lot more affect on stopping distance than whether you have shields or not in the rain.

[steveg]

To summarize: the best-handling (lightest) brake upgrade would be aluminum 4-piston calipers (AHspares, Wilwood) with the lighter pre-BJ8 3/8" rotors and no dust shields.

[HealeyRick]

To summarize: the best-handling (lightest) brake upgrade would be aluminum 4-piston calipers (AHspares, Wilwood) with the lighter pre-BJ8 3/8" rotors and no dust shields.

Would the aluminum calipers work with the thinner pre BJ8 calipers or would the piston travel be too much?

[red57]

Would the aluminum calipers work with the thinner pre BJ8 calipers or would the piston travel be too much?

I don't know for sure but my guess is the earlier 3/8" rotors would work fine - only 1/8 thinner, so 1/16" more piston travel on each side and I would bet that wouldn't be a problem.

BTW, as far as unsprung weight is concerned, when I mentioned the dust shields I'm mostly laughing at myself because in racing we become obsessed with things....I know one racer who questioned whether filling the tires with nitrogen resulted in less unsprung weight since nitrogen is lighter than air? Or, some who won't use acorn lug nuts because they add a few ounces to the weight of the wheel. In street driving these things probably don't really matter much IMO.

When it comes to the rotors, my own speculation is that the simple weight difference may be marginal but the rotating gyroscope effect is what I feel as a difference because it feels like the steering is 'stiffer' to turn. May all be in my head though. I do know I raced with 3/8" rotors for over 10 years and the only issue was since they can't dissipate heat as well, there was more pad material transfer requiring skimming more regularly. But, during that time I also averaged 5000 miles street driving every year and never had pad material transfer or any other problem while street driving which is why I'm going back to the 3/8" on my car. (PS, I run Porterfield R4 carbon Kevlar pads)

Dave