Bettter Braking in the Rain

[TomoHawk]

I think the brake pads are the Duralast ones (semi-metallic maybe)?

While I'm at it, I could put on the 4-pot calipers too, huh?

Has anyone tried adding some kind of squeegee to the pad or caliper? It probably wouldn't have to touch the rotor;  just be close enough to direct or deflect some water away, or get a bit of vacuum action to suck out some water (or warm air when it's dry.)

Edited February 27, 2016 by TomoHawk

[Chickenman]

Squeegee's aren't necessary when everything is 100%.  ZCarDepot has some Hawk HPS pads for sale at $59.95. The Hawk HPS are a known good pad in the rain.

4 pot calipers are nice, but not really necessary on the street IMHO. The stock Z braking system on the front is actually pretty good. More than adequate for the street and Autocross. If you consistently run track days, then you may want to run bigger rotors ( to dissipate heat ) and 4 piston aluminium calipers ( to dissipate haet from fluid ) . We ran in ICSCC D-Production back in the late 70's and early 80's and could out brake C-Production Porsche 911S's with just a few modifications to the stock braking system ( Ferodo DS11 front pads, cooling ducts and " Green Stuff " rear shoes ). We never ran out of brakes and this was on a Track that was VERY hard on brakes ( Westwood ). Rules did not permit us to upgrade brakes, so we had to run what the car came with. 

The rear brakes need upgrading to discs if you do upgrade the front. So it can start running into a lot of $$$ Be careful about running larger brakes up front without doing something to increase rear braking force. You can end up with too much front brake and actually increase stopping distance, because the front's lock up too soon. It's a common mistake with people upgrading to Big Brake Kits. It's all about balance.

 

 

[TomoHawk]

The 79 pickup calipers are already on the vehicle.

 

[Chickenman]

That's the Toyota 4 runner calipers? Well if they already on it it's a done deal. No big worries.

The big deal is when you start changing rotor diameters and pistin volumes. Clamping pressure is controlled by piston volume.  Doesn't matter if you have two large pistons or 4 smaller pistons. As long as the piston " Volume " is the same ( or reasonably close ) then the Clamping force is not altered too much.

WilWood has a chart for calculating piston volumes for various Piston sizes. Comes in very handy when doing caliper swaps.

[Zed Head]

1 hour ago, TomoHawk said:

The 79 pickup calipers are already on the vehicle.

So this whole discussion, aside from rossiz's post, has been about a modified front brake setup?  Shields removed?

He said the brakes were fine when it was dry.  Don't know why you'd do anything more than try to keep them that way.  Add a shield.  Don't fix unbroken stuff.

[Chickenman]

^ Yeah, I'm rather confused.... First Tom says he has stock discs. Then he says he's thinking of adding a shield over the disc. Then he's not sure if the stock shields are in place. Then he says he's thinking about adding 4 Pot calipers. Then he says he has 79 Pickup calipers already on it ( I'm thinking the popular  4 piston Toyota Pickup calipers ) ... At this point I have know idea what he has????

Edited February 27, 2016 by Chickenman

[Zed Head]

Looking at your preceding post, I think that he meant he had the 79 calipers on the rear.  My mistake.  But still, unclear which disc shields are being discussed.

 

[TomoHawk]

The vehicle has the stock rotors but someone put on the '79 pickup calipers.  Recently I noticed the braking problem in heavy rain, so I think some shields should go back on if they aren't on, which is not easy, or some different brake pads would help, which is easy. I have some 4-pot calipers, but that would not be easy to install, and probably not even needed.

I haven't looked at the front brakes for several years, so I don't know what condition they are in, but the pads are definitely not worn out.

The rear brakes are the stock drum brakes.

And yes, I'm considering a lot of different things you could do. The stock calipers are not too expensive to buy  and would be easiest to put on to get back to a know point of operation, and go from there.  I don't see a real reason to keep the pickup calipers, because they don't seem any better, and aren't the same units as the stock calipers, and probably use different pads too, so you just can't go to a brake shop to ask for pads because they'll  turn you down for not have a factory/stock vehicle (if you modify your vehicle, you are totally on y our own except for oil changes.)

I haven't used the 4Runner calipers because they need to be rebuilt and you also need the larger master cylinder, which is more-or-less NLA, so the whole 4-pot thing isn't even necessary at all, because the stock calipers should be adequate anyway.

So now I am back to the idea of putting on some kind of dust/water shield and/or different pads with stock calipers..

Edited February 27, 2016 by TomoHawk

[Chickenman]

I'm still not sure what 1979 Pickup calipers on on there. Are you saying they are 1979 Datsun Pickup calipers? Because that should make them a single piston sliding caliper design. Is that's what's on there Tom? If so I would defiantly change back to the stock Z caliper. The sliding type calipers tend to flex. The factory two piston Z calipers are a fixed mount and are actually pretty darned stiff if my memory serves me correct. Stiff is good in brake calipers and other things.....

Either way you definitely want the dust/water shields on there. Can you take a picture of your setup? Just curious....

[TomoHawk]

1979 Toyota pickup calipers.  That was one of the 'upgrade' options for the calipers. IFAIK, the Datsun pickup calipers were not an upgrade option.

 

[Chickenman]

OK, I understand now.... I think.  You are running the Toyota Pickup 4 Piston Iron calipers. And you have a spare set of Toyota 4 Runner calipers.

I knew that the 4 Runner had 4 piston calipers, but I didn't know that the Toyota PU also had 4 piston calipers.

[TomoHawk]

The 2WD 1979 pickup had 2-piston calipers, and it looks like the 4WD pickup has 4 piston calipers.