Calipers

[patt107]

Do you guys know of any brake calipers that have the built in emergency brake? i know about the Cadillac ones, but there has to be a more commonly found caliper out there that can be used. Im doing a disc brake swap on a 14FF rear and i need to retain my emergency brakes for insection purpose.

pat

 

[ntsqd]

The Cad hydro-mechanical calipers are not a great idea. When they work they're OK, but when they don't not only does your P-brake function suffer, but the service brakes suffer as well. An absolute with those calipers is that you MUST keep the p-brake adjusted correctly and you CAN NOT count on the self adjuster to do that.

The best Parking brake comes on the late 14bff's that have rear discs. These have a drum type parking brake built into the rotor hat. All of the OE's have gone away from the hydro-mech. type p-brake caliper design. I see that as a no-confidence vote.

 

[cbbr]

Some people like these. I have not tried them, but it is on my list.

 

[neverendingproject]

There is a smaller caliper that came on the caddy's riviera's and toronado in the mid to late 80's.

 

[cbbr]

I thought that it was too narrow to fit.

 

[dyeager535]

I know there have been problems with the Cadillac stuff, still not convinced it's anything other than operator error in most cases. If you use the e-brake as you should (all the time) it keeps the pads in close proximity to the rotor. GM actually used that style well up into the 90's, and if I'm not mistaken, some OEM have actually gone BACK to that setup. (no examples now, but I'd have to start looking at old posts here) Again, there is room for owner error in the Cadillac design, I don't see anything other than that leading to their disappearance.

Drums likely hold somewhat better in that application, gotta give them that.

As to other applications that might work...the late 70s early 80s smaller cadillac stuff would probably work for many applications, however they take thin rotors. Some '88+ C/K rotors are supposedly thin enough to work, but I haven't found any yet. Problem with thinner rotors then is finding some that are close to the right thickness, but also with the 6 lug GM pattern. That takes a lot of work to narrow down from all the other makes.

 

[ntsqd]

No doubt that operator error plays a part in their not functioning as they should (and they are particularly susceptable to not functioning as they should), but I've had two friends bail out of them. Both were WELL aware of the need to keep using the p-brake. One is a pretty savvy Mechanical Engineer who took them apart to figure out what exactly had to happen to make them work. I've posted the link to his tech write-up in the past.

What he found was that few, if any, of the rebuilders actually rebuild the adjusting mechanism. So even a rebuilt caliper doesn't guarranty that the p-brake function will work properly. And as we know from experience, if the p-brake isn't adjusted correctly on those, the service brake performance is considerably substandard.
So he rebuilt the p-brake part himself. After about 2 years on his truck, which does not see deep mud or other similarly trying experiences and is basically street & dirt road driven only, they needed rebuilding again. Once the basic adjusting mechanism starts to sieze up you're done.

When I worked as a Design Engineer @ Wilwood I asked my mentor there about them when we were working on a p-brake system for one of the utility vehicle mgfrs. He said what I've often repeated here, "Hydro-Mechanical calipers are a bad idea. There just isn't a good way to design a long lived adjusting mechanism and without that performance will suffer."

The fact that the domestic OE's bailed out of them and went to a quite probably more expensive design tells me a LOT more than how long they used them. Since they had the tooling to make the hydro-mech's and they chose to spend the money to go to something else when the part(s) in question are not cosmetic or model year related means that they had discovered some sort of problem with the basic design. That OE's like Volvo and Mercedes have always used the drum p-brake design is further evidence against the hydro-mech's.

So the short term answer is yes, you can make them work. The long term answer is not for long enough to be worth the $$ up front for a caliper that is getting rare.

A drum style p-brake is inherently a better idea anyway. Drums have a lot of contact surface area and make much better static holding devices than do discs. A project I'd like to take on sometime is to work out how to use the old drum p-brake off the rear of a 2wd SM420. That design, if not that actual set of part, looks to me to be the most promising.

 

[patt107]

I have searched just about every disc swap thread on here and i just got better info from you guys in a matter of hours!! I really appreciate the help i think im going to eliminate my ebrake setup till i can get the transfer case i want(205) and do a transfer case ebrake setup.
thanks
pat

 

[dyeager535]

I thought we'd broached this topic before, but I wasn't sure who it was, now I know.

No argument drums hold better in an ebrake situation, don't they make the drum in hat style quite small to fit? Not only that, how do the drum-in-hats adjsut as well? Do the newer vehicles just take up slack in the pedal/handle for the e-brake, or is it the same as drum rear brakes with an adjuster wheel that requires e-brake use to keep them functional?

I don't disagree that the rear cadi's aren't the best out there, unfortunately no one (still!) seems to have taken the time to find something else common that can be easily (cheaply) bolted in place. I've searched a bit, but I don't have the resources and time to spend looking through hundreds of options. I had heard some Ford Explorers had some decent brake pieces that might be adaptable.

 

[RootBreaker]

well lets see... I actually stop better with the rear disc... so ebrake is no biggie to me... however inspection wants to look under there and see it... so I pass... I use it every time I can... however... I dont count on it holding.... L on my smc will do for that....

 

[ntsqd]

There is a smaller caliper that came on the caddy's riviera's and toronado in the mid to late 80's.

There are two basic sizes of calipers, and within the smaller size two different piston sizes. The larger of the two uses the industry std pad number D52 and the smaller, so-called "Metric" caliper uses the D154 pad.
Nominal piston sizes in the non p-brake calipers are 2-15/16" and 2-1/2" respectively. In the D154 calipers there are two pistons sizes. I do not yet know whether one is smaller than the 2.5" 'normal' piston, or is larger.

I thought we'd broached this topic before, but I wasn't sure who it was, now I know.

Raises hand.

No argument drums hold better in an ebrake situation, don't they make the drum in hat style quite small to fit? Not only that, how do the drum-in-hats adjsut as well? Do the newer vehicles just take up slack in the pedal/handle for the e-brake, or is it the same as drum rear brakes with an adjuster wheel that requires e-brake use to keep them functional?

There are two basic designs that I've seen. The GM design uses one shoe that is nearly a full circle. I've only seen the shoe & never the backing plate so I'm unaware of any adjuster/adjustment method. The Exploder design uses two more normal looking shoes.
Going on memory (risky) the Exploder design uses the cable tension as the adjuster.
My ME friend who bailed out of the Cad's went to the Exploder design. Not only is the rotor smaller, but so is the caliper. On his Early Bronco he says there is very little difference in service brake capability and the p-brake works better than the Cads did even when adjusted as only anal-retentive Engineers are likely to adjust them.
For a K5, Sub, or FS truck they might be a bit small for off road use. I'd look at the late 14bff's that came with rear discs. Those use the rotor hat drum p-brake design too. As do the rear discs on the PSD's and similar aged SD Fords.

I don't disagree that the rear cadi's aren't the best out there, unfortunately no one (still!) seems to have taken the time to find something else common that can be easily (cheaply) bolted in place. I've searched a bit, but I don't have the resources and time to spend looking through hundreds of options. I had heard some Ford Explorers had some decent brake pieces that might be adaptable.

I've pondered this many times and even poked around a little. I've concluded that it's more time effective to buy or build a driveline brake. Since both of my rigs now sport Detroits I'm not as concerned about tire slippage as I would be with an open diff.

 

[dyeager535]

I've pondered this many times and even poked around a little. I've concluded that it's more time effective to buy or build a driveline brake. Since both of my rigs now sport Detroits I'm not as concerned about tire slippage as I would be with an open diff.

My concern with the driveline brake is the cost in setting it up right. Of course, unless someone comes up with another setup that bolts onto the axle and works as is, rear disks will continue to be expensive as well.

I somewhat doubt the 14FF stuff will work on any of the semi-floating stuff, but I'll confess to never seeing the drum in hat parts in person. Unfortunately I think the 10 bolts were the only rear disks GM put on the trucks, and if memory serves, they went back to drums on those as well.

 

[shane74]

Some '88+ C/K rotors are supposedly thin enough to work, but I haven't found any yet. Problem with thinner rotors then is finding some that are close to the right thickness, but also with the 6 lug GM pattern. That takes a lot of work to narrow down from all the other makes.

Yes, there is one specific year that works with the smaller e-brake calipers on the 6 lug axles with some modification. The mods are easy to do if you have a lathe or CNC. If not, you really can't do it on your own easily.

I am still running the 203 t-case and am working on a d-line mechanical e-brake that mounts on a separate x-member tucked up inside the frame rails. It also requires using a flange on the ouput of the 203 like the 205's. After years of trying to figure it out, this seems to be the best, strongest option.

 

[ntsqd]

My concern with the driveline brake is the cost in setting it up right. Of course, unless someone comes up with another setup that bolts onto the axle and works as is, rear disks will continue to be expensive as well.

I somewhat doubt the 14FF stuff will work on any of the semi-floating stuff, but I'll confess to never seeing the drum in hat parts in person. Unfortunately I think the 10 bolts were the only rear disks GM put on the trucks, and if memory serves, they went back to drums on those as well.

Ya' know, I've been thinking all along in terms of a 14 or a 60. Might account for the mis-match in communication.

Yea, a 10 or a 12 (and maybe even the 14 SF) would complicate things. Not qualified to comment on them as though I currently own a 10 it came out of the truck within the first 1k miles of my ownership.

Since a big part of my job is figuring out how we're goning to get things made that isn't a big deal to me. I'm so used to it that I forget others don't know some of these things.

The rotor for a disc type driveline p-brake could probably be made for in the range of $120-$150 at the onesy-twoesy price level. That would be CNC plasma it, stress relieve, & blanchard grind. The trick is the caliper. I'd have to check a source, but generally mechanical calipers are not an easy thing to get enough leverage out of and still have a decent package size. (Note the size of the unit in the link below.) Mico makes some, as do one or two other mfg's. Wilwood used to sell a Mico just for p-brake duty. Don't know if they still do or not. The bracket may or may not be easy depending on what the caliper is.

With a flanged output it gets real easy rotor-wise. I think All-Pro still sells their t/c mounted p-brake set-up. Yep, they do. Yota t/c's conveniently have all kinds of bolts sticking out of a lot of places. Makes mounting brackets much easier.

 

[Gravel Maker]

Another direction for calipers....

Toyota Supras used an ebrake within the caliper design, I confess I haven't had the time yet to check them out.....

Personally, we are working on a design along the Toy FJ40 drum style, of course using a disk but we still have questions to answer. Like how small a diameter is really feasable for the parking power required? I don't want to yet ignore MC calipers either, some of the modern big bikes weigh nearly 1000lbs and the really can stop on a dime, but we aren't asking it to stop a 5000lb vehicle, just hold on to it, I think they may be capable.

But my insurance company may force me to not make any ebrake systems. We will see.

 

[jarheadk5]

My '93 Plymouth Laser had rear discs with hydro/mech calipers. I was able to lock-up the rear wheels at speed with the E-brake handle, so there wasn't a power issue. The rotor was a thin (non-vented) one though, so that complicates things a bit.

BUT... shane74 hinted that there's a thin disc out there that can be made to work. I guess he doesn't want to spill the beans with a part # or application, though. Understandable - he can probably make a little $$$ from it.


Gravel Maker - don't call it an emergency brake system - call it a parking brake system. Might tilt the odds in your favor...
BTW - I get a blank white screen when I click your website link. Normal?

 

[neverendingproject]

My '93 Plymouth Laser had rear discs with hydro/mech calipers. I was able to lock-up the rear wheels at speed with the E-brake handle, so there wasn't a power issue. The rotor was a thin (non-vented) one though, so that complicates things a bit.

BUT... shane74 hinted that there's a thin disc out there that can be made to work. I guess he doesn't want to spill the beans with a part # or application, though. Understandable - he can probably make a little $$$ from it.


Gravel Maker - don't call it an emergency brake system - call it a parking brake system. Might tilt the odds in your favor...
BTW - I get a blank white screen when I click your website link. Normal?

Shane was talking about 6 lug 88-98 4x4 front rotors or the 99up front rotors. I forget which one is skinnier, but you can turn em down to make em work with the small caddy calipers. I used the 88-98 front ones for my big caddy calipers, but when I think about it, I think the 99 up is a little skinnier. There is also a rotor that was used on isuzu troopers (dont know the year) that will work with the small ones, but I had already acquired the big calipers.

 

[shane74]

BUT... shane74 hinted that there's a thin disc out there that can be made to work. I guess he doesn't want to spill the beans with a part # or application, though. Understandable - he can probably make a little $$$ from it.

Nope the $$ part has nothing to do with it. The reason I don't give out part #'s very much is that specific parts are designed to work together with the kits we make. For instance, if you buy brackets from one manufacturer, and then go buy the rotors that we use (especially true for all the different 6 lug kits we make), they may not work together. I have run into this in the past with tie rods and other parts and they don't always work. People get pissy when I tell them sorry, but you didn't buy everything from me, and I don't have other manufacturers products on the shelf, so no, I can't trouble shoot your rig for you and garuantee it will work. I'm not trying to come off as an ass, but I can't fix it if I don't know what I'm working with. I don't buy anything from any other manufacturer and copy it. Our designs are original. Therefore, the parts we use may not always work with other manufacturers parts.

The rotor I am talking about is very specific in application. It took me weeks of looking to find it, and another couple weeks of R&D to make sure it works and works well. Everything we make has to stand up to our "You break it, we replace it" warranty. It is the right thickness for the smaller calipers, slides over the axle shaft (no stud removal ), and requires only slight modification on a lathe or mill to work with OUR kits. It may not work with another set of brackets. If anyone is interested, I'll gladly give out the application, but folks need to understand that I am not going to spend hours on the phone trouble shooting a rig that has another manufacturers parts on it. I don't know what combination of parts they have designed their kits to work with.

 

[shane74]

Shane was talking about 6 lug 88-98 4x4 front rotors or the 99up front rotors....but you can turn em down to make em work with the small caddy calipers..

The rotors we use do not have to be turned down. I found them by looking through several different rotor spec. books page by page until I found it. Talk about a cure for insomnia

 

[dyeager535]

If you wouldn't mind posting, I'd be curious to hear. Way too much talk about them being out there (not by you of course) yet nothing that I've seen has yet come out in the open.

I've already got the small calipers (not sure if they will go on the truck or car ten bolt) but I know they are a heck of a lot easier to find.

The newer 6 lug Astro rear stuff (13"!!) would be pretty sweet, but I doubt it would all fit under a stock 15x8 wheel.