dual brake calipers? (1 Viewer)

[wcbr]

Things were slow a few days ago, so I went down the YouTube rabbit hole, and came across this video:



I have not seen mention of a dual caliper setup on an 80 series, but it seems like a pretty single banana and potentially low cost type project (assuming there is room and a bracket could be fabricated for an LX/80).

To be clear, I'm not thinking of a hydraulic hand brake, but the notion of using a T and having increased actual braking ability and increased pad life.

I've been away from my LX for a few months, driving Fiats around Italy, thinking about what an 80 would be like in Rome...

Thought it might be an interesting topic to throw out for discussion here.

Wc

 

[LINUS]

I see it for his application so he can run a hydraulic whammy bar / drift brake.

For myself I quit towing with my 80 so that made all the difference. I'm only on stock calipers & EBC green pads now, fairly fresh ones NAPA had 24hrs away vs my last that were yellow or orange (forget) that you have to pre-order. NAPA stock replace rotors, no fancy stuff.

It works great being they are the biggest FR brakes the 80 got, behind the 16" stock wheels - and again not towing anymore.

I would personally run a FR Tundra caliper & see about the bolt pattern to see what rotors would work if needed a change. The pads are good sized, just looking through my spokes on the Tundra I have.

Seems the talk of late was the new Hi-steer knuckles being cast were going to be for Tundra caliper fitting too, if that's of any interest to you.

 

[bloc]

Seems like a really good way to push the rotor into thermal failure. Also with twice the caliper piston surface area on the axle without twice the master cylinder S/A your pedal will suddenly turn to mashed potatoes.

Get HIGH QUALITY rotors, slotted if possible, and a good pad like EBC green (or yellow if you don't mind LOTS of corrosive dust and rotor wear..). 80-series brakes are actually pretty good when set up correctly.

Or get a big brake upgrade.

It's a 20+ year old 5k+ pound SUV. don't expect it to drive like a car.

 

[wcbr]

Good points. I am running EBC greens, new OEM calipers, with drilled/slotted rotors up front and a new master cylinder.

I suppose it would help to drive another lx/80 to see where my braking compares to others as a reference. My brake lines are the originals, if anything those would likely be the next best area to investigate.?.?

I ran into a situation a few years ago, just after purchase (43,000mi), where my stock LX could not hold itself on a somewhat steep slope driving around on the family ranch in the Texas panhandle. I had to drop down into Low to not bump the Excursion ahead of me. I have not had a chance to test that scenario since then, but all of the brake components have been upgraded with the exception of the soft lines.

 

[Maleficio]

Maybe a stepped brake system? Stage one and stage two. Stage one handles regular driving, stage two is a supplement to quickly slow down a vehicle weighing 6500 pounds plus.

 

[mudgudgeon]

Haha, I think we went down the same rabbit hole!
I was thinking the same as above regarding pedal feel.
without changing the master cylinder, you'd have twice the caliper piston volume to fill on the front, and therefore half the piston pressure. but no change on rear calipers.
You'd have to push the pedal further to apply the same pressure to the front, but you'd have much more pressure in the rear (for a given amount of master cylinder travel).

More pad contact area on the front, but less clamping force.
Not sure how it would pan out.

 

[JeepinPete]

This falls into the category of improving something that doesn't need to be improved. The basic 80 brake system components are more than enough to get the job done. But it is a 20+ year old vehicle, the parts will not work like new, even if they seem to be working fine.

I'm running a wide 37" tire. Brakes were marginal at first. I did an ABS and LSPV delete. Installed Hawk LTS pads. Had replaced both front calipers before the tire upgrade. Brakes are now great power wise. The rear is a bit stronger under heavy, lock 'em up braking. I see two choices to correct that issue. One is to install a less grabby rear pad. I probably will not go that route since I do tow 5000 lbs on occasion. The second option is to install an adjustable proportioning valve for the rear circuit. This will let me dial down the rear brakes when I am not towing, and to up it when I am.

I know many are against removing the ABS system, and I certainly understand why. But I'm pretty convinced from first hand experience that the 20 yo ABS block is the root of weak braking on these trucks. Hate to think what Toyota would charge for a new ABS unit...

 

[veiloctane]

Haha, I think we went down the same rabbit hole!
I was thinking the same as above regarding pedal feel.
without changing the master cylinder, you'd have twice the caliper piston volume to fill on the front, and therefore half the piston pressure. but no change on rear calipers.
You'd have to push the pedal further to apply the same pressure to the front, but you'd have much more pressure in the rear (for a given amount of master cylinder travel).

More pad contact area on the front, but less clamping force.
Not sure how it would pan out.

I would be interested in seeing a dual front and rear caliper setup. I know the 1997 and up 80s came with bigger brakes front and only fit larger. 16"+ wheels. Doubling it up would be double the surface area on the rotors alone not sure how well it would hold up.

 

[scrowley]

Delete abs, delete lsvp, stainless brake line kit, ebc yellows. Crazy good brakes!!

 

[shocktower]

Delete abs, delete lsvp, stainless brake line kit, ebc yellows. Crazy good brakes!!

K.I.S.S Keep it simple Simon, all of the fabs for a great stock braking system, and wasting time and possible safety issue, go with the deleted ABS and LSVP and new brake lines and pads

 

[bloc]

I would be interested in seeing a dual front and rear caliper setup. I know the 1997 and up 80s came with bigger brakes front and only fit larger. 16"+ wheels. Doubling it up would be double the surface area on the rotors alone not sure how well it would hold up.

97 has the same brakes as 93-96.

If you are talking about 98+ 100-series.. yes. Larger pads and calipers. Not sure about rotors. They were IFS which may allow for more rotor surface area in a given wheel due to a smaller hub.. but that last bit is speculation on my part.

 

[Dave 2000]

Last year I went with new discs all round slotted/dimpled, IIRC Mintex pads, new callipers all round and new master cylinder, took freaking ages to get the air out, ABS/LSPV all still intact, brakes brilliant or should I say as good as when new, no issues with insurance or authorities at test time.

Don't expect modern braking performance from a system that was designed in 1986.

regards

Dave

 

[msapers]

Ok, but it would be nice to stop better than my 1970 Chevy 3/4 ton 4x4 with 4 wheel manual drum brakes.

 

[Dave 2000]

@msapers Hmmmm, you might want to check out your 80 brakes? I find the stock brakes fine in normal use, they do tend to fade if you drive with some enthusiasm. I did the brake upgrade and have still managed to make them fade but only when pushed hard. Emergency stops no problem, although the handbrake leaves much to be desired.

regards

Dave

 

[scrowley]

100 pads are known to last longer but not add braking force.
EBC yellows are the way to go. Def. Not if you are a city driver as they don't last very long. Got about 8-10k on last set. Mostly around town and wheelinv.

 

[Feistl]

Bit of a thread dig, but contemplating running dual calipers on the rear (one with a built in handbrake). I’m wondering that if adding another caliper halves the fluid it would in theory halve the pressure per caliper, but with two calipers overall braking force should remain relatively the same? (Just with double the pad life).

Alternatively, does anyone know if the drum style rear master cylinder displaces a larger volume of fluid?

 

[BILT4ME]

Bit of a thread dig, but contemplating running dual calipers on the rear (one with a built in handbrake). I’m wondering that if adding another caliper halves the fluid it would in theory halve the pressure per caliper, but with two calipers overall braking force should remain relatively the same? (Just with double the pad life).

Alternatively, does anyone know if the drum style rear master cylinder displaces a larger volume of fluid?

No and no.

It would split the volume between the two pistons and it would halve your pressure and your master cylinder would run out of travel and volume before you would get total pressure in the system.

The drum brake piston is smaller than the disc brake piston and takes less total fluid for movement.

The dual caliper in use for a parking brake system would have to be a completely independent system in order to still have your normal brakes.

 

[Feistl]

Once the calipers are bleed though they would be full of fluid. So say depression of the brake pedal normal results in 4mm of piston travel then doubling the area would halve the travel (to say 2mm) which is effectly half the force. But if you’ve got double the pad area then braking should be similar.

The only reason I’m not sure about that answer is I recently upgraded my brakes on my road car from 2 piston fronts and single piston rears to 6 pot fronts and 4 pot rears and it didn’t require a master cylinder upgrade. The total size of the 6 pistons fronts was about double the size of the original 2 pistons... yet the braking is massively improved. I’m also wondering if there’s enough “spare capacity” in the 80 series master once the lspv is removed (as people suggest adding a biasing valve after removal). That would seem to suggest there is “excess” volume in the master which would help with the additional caliper?

 

[BILT4ME]

Once the calipers are bleed though they would be full of fluid. So say depression of the brake pedal normal results in 4mm of piston travel then doubling the area would halve the travel (to say 2mm) which is effectly half the force. But if you’ve got double the pad area then braking should be similar.

The only reason I’m not sure about that answer is I recently upgraded my brakes on my road car from 2 piston fronts and single piston rears to 6 pot fronts and 4 pot rears and it didn’t require a master cylinder upgrade. The total size of the 6 pistons fronts was about double the size of the original 2 pistons... yet the braking is massively improved. I’m also wondering if there’s enough “spare capacity” in the 80 series master once the lspv is removed (as people suggest adding a biasing valve after removal). That would seem to suggest there is “excess” volume in the master which would help with the additional caliper?

Knock yourself out.

It's all about volume and pedal travel with a stock MC....

 

[scottryana]

Why stop at 2?? I bet you could fit 4 or 5 calipers around the rotor.