86 4Runner build

[sami]

i'm planning on doing the rear trunk as well in my '87 4runner... i've just recently been toying with ideas on a two layer box, the bottom as an aux fuel tank, and top half cargo trunk...

total dimensions of 14x13x30, and split it for 6x13x30(fuel), and 8x13x30(dry storage).. that's 2,340CI or 10.12 gallons of aux fuel, and 3,120CI's or 13.5 gallons of dry storage. I like it anyways...

Nice build so far, i've been keepin my eye on it. I'll post up my '87 once it's worthy to grace these pages.

-Jason

[GroversYota]

Originally Posted by sami

i'm planning on doing the rear trunk as well in my '87 4runner... i've just recently been toying with ideas on a two layer box, the bottom as an aux fuel tank, and top half cargo trunk...

total dimensions of 14x13x30, and split it for 6x13x30(fuel), and 8x13x30(dry storage).. that's 2,340CI or 10.12 gallons of aux fuel, and 3,120CI's or 13.5 gallons of dry storage. I like it anyways...

Nice build so far, i've been keepin my eye on it. I'll post up my '87 once it's worthy to grace these pages.

-Jason

Nice build! Did your fuel milage change from stock being geared for the larger tires?

[Grim Reaper]

Stopping is good! Wish my truck would stop!

Few weeks ago my wife and I decided to sell one of our three drivers. And of course as soon as we sell one and no longer have a "Back up" available things start tearing up when I can't just drive the extra vehicle and fix at my leisure.

We had to put our 454 Suburban back on DD duties (the Honda was sold since it couldn't pull the camper and was not 4wd). So last week the Burb starts leaking power steering fluid from the high pressure hose. Ended up spending most of my weekend on that. I have been driving it making sure it is not going to give my wife any problems before turning her loose in it. She has been driving my 4Runner

Thursday I get a call from her that the brakes feel funny....Not good. Master cylinder is done. Looks to be original so hay 22 years and 220k I can't really complain.

In fine tradition this means TIME FOR AN UPGRADE!!!!!!!!!!

Toyota changes brakes with engine size. a 4cyl will have smaller capacity brakes then a 6 Cyl. Toyota really built to "just enough" on the brake system. Throw in some 33's and my 4cyl truck just did not have great brakes. Add a trailer...it was border line dangerous. Stopping distance was starting to get pretty long.

After some research I found a few things out.
86-95 appear to have the same knuckle.
86-89 used the same front rotors
90-91 used a little thinker rotor.
92-95 was even thicker.

Thicker rotor means more heat capacity and less warp tenedency.

The turbo and V6 trucks did have calipers with larger pistons then the 4cyl trucks. Again their width determined by the rotor.

So what I will be doing tomorrow is installing 92 Rotors and calipers on the front. Simple shoe change in the back.

Some of my reading I ran across a few that say as long as I keep the rear brake adjusted up I should not have any problem running the 4cyl master (and this saves me from also having to put a V6 booster on it. The theory is the smaller master will generate more pressure to the larger pistons.This will make the peddle lighter effort with more braking power.

Where the problem comes in is if there is enough fluid capacity to handle the larger pistons.

Should have the sorted out by Sunday at the latest.

[ntsqd]

Over the years I've had folks swear that the V6 calipers have larger pistons. None of my parts books confirm this, they all say that the V6 & 4cyl caliper piston size is the same. So I don't know what to think. I don't doubt them, but I wonder what the source of their intel is. One of these days I guess I should buy a V6 caliper & take it apart.

The real advantage of a thicker rotor is two-fold. The greater thermal mass means that it takes longer to reach a given temperature. And the larger vents in the middle allow it to cool off faster.

[Grim Reaper]

Originally Posted by ntsqd

Over the years I've had folks swear that the V6 calipers have larger pistons. None of my parts books confirm this, they all say that the V6 & 4cyl caliper piston size is the same. So I don't know what to think. I don't doubt them, but I wonder what the source of their intel is. One of these days I guess I should buy a V6 caliper & take it apart.

The real advantage of a thicker rotor is two-fold. The greater thermal mass means that it takes longer to reach a given temperature. And the larger vents in the middle allow it to cool off faster.

I started looking around after reading your post and I think I see where the issue is and I think you are correct.

I have always read V6 had bigger "caliper" and everybody says to ask for 90's V6 parts but It looks wrong that it is a V6 difference on the caliper.

I went through some of the online parts places like Autozone and Parts America. You are correct that they show the same calipers for 4cyl and 6cyl.

It looks like a year change where the calipers got larger.

Where the caliper change comes is mid 89. It starts showing a different rotor and caliper. If the images are correct you can see where the early 89 back use callipers with two big pistons and two small pistons. Late 89 up through 91 are all showing 4 large pistons and different rotor and again a caliper and rotor change in 92 but showing 4 large pistons.

I bet 92 is the start of the 31 inch tire option. That is probably the biggest ones available. Now I wonder if I have enough master cylinder.

The parts store had the 86-to 3/89 rotors in stock and the 92-95. The disc is at least a 1/4 inch thicker maybe 3/8's. A LOT more meat to it. Diameter is the same. They didn't have any parts for the late 89-91 for me to look at to see what is different for those years. I bet the thickness is it.

I will get pictures of the rotors and calipers today when I start swapping them out.

Here is something I am finding different: The Turbo trucks and V6 are showing a different master cylinder and booster over the 4cyl through early 89. Doesn't seem to carry through to the 4/89 up trucks They all seem to spec the same. Maybe thats where the 4Cyl vs V6 confusion comes in. Wish they listed Bore size so we could figure out just how much of a change it was.

This is interesting though becasue I have read the 90 up booster is not a direct swap. The linkage is different is what I read. The 5/89 up Boosters through 95 show the same. Is 5/89 the actual build date when they body changed?

The 3/89 down v6/turbo Master and booster should be a bolt in. That's good to know if I run into a issue with enough fluid volume.

[corax]

Originally Posted by Grim Reaper

The 3/89 down v6/turbo Master and booster should be a bolt in. That's good to know if I run into a issue with enough fluid volume.

the master cylinder bore size is usually cast into the part on the outside. a direct bolt in (for my '88 4runner with 4 bolt mount) with a bigger bore is the '94 non-ABS Landcruiser master cylinder. Just make sure if you get one, you get the fluid reservoir with it. I think, but not sure, the difference is 5/8" vs 3/4"

[Grim Reaper]

Originally Posted by corax

the master cylinder bore size is usually cast into the part on the outside. a direct bolt in (for my '88 4runner with 4 bolt mount) with a bigger bore is the '94 non-ABS Landcruiser master cylinder. Just make sure if you get one, you get the fluid reservoir with it. I think, but not sure, the difference is 5/8" vs 3/4"

Did you keep the stock 88 booster?
4cyl or V6 88?
How is the peddle feel?

[corax]

Originally Posted by Grim Reaper

Did you keep the stock 88 booster?
4cyl or V6 88?
How is the peddle feel?

Actually I was wrong. '94 FJ80 Lancruiser non ABS master cylinder has a 1" bore, not sure what the original 4runner bore is, but it is cast onto the side.

originally mine was a 4cyl. direct mount onto the original booster. I was going to do this, but changed my mind - most report a firmer pedal (less travel to take up the "slack" but less hydraulic leverage, so you have to push a bit harder). Marlin Crawler sells them with this description:

Replacement master cylinder for older Pickup's and 4Runners with smaller bore (bore size is cast into right side of housing). Fits 1979-1995 Pickup/4Runner. Features 1" piston and residual valves for both front and rear. Works with both drum and disc brakes. Bolt on installation. Includes reservoir. On 1979-1985 Trucks and 4Runners the smaller factory bore works fine with stock, solid front rotors and 8" rear drums. If you upgrade the rear to larger 1986 and up, 10" drums and/or upgrade the front to a vented style caliper you will want to install a 1" bore master cylinder like this one for additional volume.
(http://www.marlincrawler.com/htm/brakes/mcylinder.htm)

[Grim Reaper]

Originally Posted by corax

Actually I was wrong. '94 FJ80 Lancruiser non ABS master cylinder has a 1" bore, not sure what the original 4runner bore is, but it is cast onto the side.

originally mine was a 4cyl. direct mount onto the original booster. I was going to do this, but changed my mind - most report a firmer pedal (less travel to take up the "slack" but less hydraulic leverage, so you have to push a bit harder). Marlin Crawler sells them with this description:

Replacement master cylinder for older Pickup's and 4Runners with smaller bore (bore size is cast into right side of housing). Fits 1979-1995 Pickup/4Runner. Features 1" piston and residual valves for both front and rear. Works with both drum and disc brakes. Bolt on installation. Includes reservoir. On 1979-1985 Trucks and 4Runners the smaller factory bore works fine with stock, solid front rotors and 8" rear drums. If you upgrade the rear to larger 1986 and up, 10" drums and/or upgrade the front to a vented style caliper you will want to install a 1" bore master cylinder like this one for additional volume.
(http://www.marlincrawler.com/htm/brakes/mcylinder.htm)

86 had a few differences over 85. The brakes were changed considerably from the bigger brakes noted above (and I think the rears on mine are 11 inches), vented front discs as well.. My 86 master will be bigger then the 85 down. I will check to see what the bore is tomorrow and report back.

Firm peddle I don't mind as long as you can still reasonably exert enough pressure to get them to lock down. I just need to be reasonable as my 90lb wife also drives this truck.

[Grim Reaper]

What a day!

Turns out the no peddle is a blown rear wheel cylinder not the master.

Played HELL trying to find wheel cylinders. Seems after hitting 5 auto parts stores and all 5 having to order for a 86. I asked for a 87 just out of curiosity. Those were in stock and wouldn't you know it they are the correct ones.

On my way home I started thinking about the brake shoes and how bad the fit the drum. They matched the curve on the ones I pulled off that were wore out in the middle. I had to pass the parts store I bought them from so I decided to stope to see if it showed a different part number for 87 over 86....Sure did!

Ran home got the shoes I bought and brought a drum along to check fit and the 87's fit like they should.

Every part I have bought for this rear axle is for a 87. Everybody's data base is ABSOULUTY wrong for 86 4Runners. I think they all have the parts listed as a 2wd. The weird part is the Wheel bearings are listed as inner and outer....Its a single sealed bearing and its the same bearing as a 85 and a 87.

So all the running around and then cleaning up the mess from the blown wheel cylinder pretty well shot the day and I didn't even get into the fronts. Truck is back on the road as the wife has running around to do this week and so do I so I couldn't leave it apart. I will mess with the fronts next weekend.


Still undecided if I want to swap the master now that I found the real source of the problem. I think I will not install it and see how the brakes work first and if they work fine then I will just return it. If they don't have enough volume with the factory 13/16 master I will look at the 1 inch 94 LC master corax recommended.