Anti Lock Brakes upgrade for our cars?

Was wondering if the 90's Caprice B body ABS components will swap into my Malibu? I know I'll have to upgrade discs/calipers & convert the rear from drums, get the sensors, etc...but what electrical/computer components would go with this? Will I have to get the entire "computer" from the donor and will I have to swap out the booster & master cylinder also? Anyone here ever do this? Thanks!

I thought driving an old car was enjoyable because it was simple and it operated like an old car?

Sorry, not to answer a question with a question...

To answer your question, yes to computer, yes to master cylinder, and no I have not done this, but have applied aftermarket ABS to a racecar, and it is no simple task.

There are a number of ways to improve braking without ABS.
Larger calipers and rotors are the simplest way for the least money.

jerry46765 wrote:I thought driving an old car was enjoyable because it was simple and it operated like an old car?

Yes to that.

I remember my old 77 Cutlass and love the way it drove, just didn't like the brakes, especially in the rain. Not that I plan on rain-driving but you never know. My two boys like the car shows and always tag along, it's more for their sake & for passing down the car so, I'm planning to upgrade for as much safety as I can get without spending a boatload of $$ & my time. I have the larger rear drums and the fronts are decent size but I like your idea too. Thanks for the advice.

If you are curious, this is overkill for a street car, but Bosch has an ABS kit. It costs like 6 grand for parts, not including the wiring loom, or a day's labor from the Bosch guy to tune it so you have a place to start driving.

http://www.bosch-motorsport.com/content/language2/html/3720.htm

It would be a complete unknown to remove an OEM ABS system from one car and attempt to apply it to another car. The system has so many parameters which are specific to the original car like weight, weight bias, wheelbase, wheel diameters, gear ratios, on and on... Plus, you have absolutely no way to plug in and tune any of those parameters. It would be tough just reset the diagnostics if there was an issue.

Anything is posssible, but will you get the outcome of 100% assurance of ABS braking performance? Unknown but not likely...

Big brakes and modern tires will help more than anything on an older non ABS car.

Thanks -

Whoa that's a whole lot of "I'm in over my head". Ya sold me on option B.

It is absolutely doable, and it's not difficult concept-wise. There is a fair amount of work involved, but it can be done cheaply with boneyard or eBay parts. I spent less than $400.00 total in parts, though I had to acquire a few new tools.

Things to consider before attempting:

o You will need the Caprice shop manual from eBay or Helm.

o You will need to use the B-body spindles/rotors, which means you will be going to a 12" rotor and 5x5 bolt pattern up front. You can use the same D52 calipers, or you can use the Caprice ones. The only difference is the Caprice ones have a metric banjo bolt.

o Your front wheels will be physically 1/4" inboard from their previous location.

o You will be doing a lot of plumbing -- the Caprice braking system uses bubble-flares while the stock components use the inverted flare, so you can plan on running 7 new lines.

o The ABS system is a standalone 3-channel system, meaning two front sensors and a single rear that (in the Caprice) reads a reluctor band on the pinion gear inside the diff housing. However, rather than swapping in the Caprice rear, you can use the much easier arrangement in the photo I posted in the Chassis and Suspension section under the topic "73-77 A vs 77-96 B suspension swaps". For that, you will need to fabricate a reluctor wheel and a bracket for the sensor. The upside to the 3-sensor system is it doesn't matter what style of rear brakes you use -- disc or drum.

o Plan on doing some wiring. The system has its own harness, but it is intertwined with the Caprice's main harness, so you will not be able to separate it out without yanking the entire thing from a donor car. Your other options are to see if a harness is available on eBay (happens every so often) or to make one yourself based on the shop manual.

o You can mix-n-match parts from 91-93 since they use the same part numbers, but 94-96 are each their own breed, so you cannot swap them around.

o The system can be connected to the stock A-body master cylinder, though the plumbing is odd since the circuits are reversed front to back. Also, while the brakes will work fine and the ABS will function, you will have about another inch of pedal travel than before. The alternative is to use the M/C and booster combo from the Caprice as well, which will mount to the old booster bracket, and will just barely allow the hood to close. However, the pedal-to-booster shaft will be too short, so you will have to extend the length of it using the shaft from the old booster (which I can show how).

o Your old combo valve gets thrown away. You will need to use the caprice combo valve, which mounts to a bracket directly beneath the M/C.

o You will need to put an ABS indicator light somewhere on your dash.

If you are still interested, I would be happy to advise on the nitty-gritty details.

Mark

I just did some hunting around, and other than '80s Mustang guys using stuff from newer models, there is nothing.
So this is cutting edge.

Let's see some pictures.

One thing I didn't give any thought was potential liability. Mentioned over and over on other sites, be involved in a highway accident with a car equipped with hybird ABS could be a ambulance chaser magnet.

But hey, I'm for pushing the envelope.

Let's see the install.
How does it perform?
What are the side effects?

Doesn't a three sensor system typically use the trigger on the ring gear of the rear axle?

Thanks-

jerry46765 wrote:It would be a complete unknown to remove an OEM ABS system from one car and attempt to apply it to another car.  The system has so many parameters which are specific to the original car like weight, weight bias, wheelbase, wheel diameters, gear ratios, on and on...

This is a complete myth.  The Bosch system in the Caprice system simply counts the teeth on the front rotors and the teeth on the rear reluctor and compares them.  Any that are too low (i.e. slipping and locking up) get modulated until they are in line with the others.  That's it.  The system does not know what vehicle it is in, since it has no relationship to anything else in the car.  It doesn't know if the car is full or empty, what kind of tires are used, what the wheelbase is, or anything.  The only time this becomes an issue is in the very late-model systems where the ABS talks to the traction control and the ECU.

The only thing you do need to concern yourself with is changes in tire/wheel sizes.  The front rotors have 34 teeth, and the rear reluctor is expected to count to roughly 68 teeth for one revolution of the rear wheels.  The Caprice has 4 same-size wheels & tires.  A change in tire or wheel size front to back will throw off the count and disable the ABS, so if you change the rear tire size, you also need to make another reluctor ring.  If your tires are the same size (even if they are smaller or larger than the Caprice, it will work fine as-is.

Photos:

ABS modulator mounted over steering box:


Stock Caprice rotor shows internal reluctor ring:


Right front wheel -- B spindle with 12" drilled/slotted rotor; black ABS cable runs from top to sensor in center of photo. 17" wheel:


From behind shows cable routing and same D52 caliper as our cars, but with metric banjo bolt:


Rear sensor on mount with fabricated reluctor ring bolted to back of pinion yoke:

Thanks Mark! At least I have something more to chew on and this is very good info for others considering the same thing. I'm thinking that a rear conversion to disc brakes & an upgrade to larger rotors & calipers all around is the way to go for me for now anyway.
-Paul

Here is the link:
https://www.g3gm.com/t5302-73-77-a-vs-77-96-b-suspension-swaps

jerry46765 wrote:Let's see some pictures.

As I mentioned, I posted a couple in the Chassis & Suspension forum.

jerry46765 wrote:One thing I didn't give any thought was potential liability. Mentioned over and over on other sites, be involved in a highway accident with a car equipped with hybird ABS could be a ambulance chaser magnet.

If the ABS is not functioning, it simply does not modulate the line pressure. Your pedal pressure goes straight through to the brakes -- i.e. normal braking. This is stated in the shop manual. If it torpedoed your brakes entirely on a failure, the factories would have have long since been sued out of existence.

That said, it's still your brake system. There are still a dozen or more ways to screw it up normally, so no one should be mucking around with it if they're not prepared to do it right. I always make the disclaimer "They're YOUR brakes. YOU are responsible. I am just showing how I made it work."

jerry46765 wrote:How does it perform?

It performs like ABS. It isn't there until you need it.

jerry46765 wrote:What are the side effects?

As I mentioned, if you use the stock M/C and booster, expect more pedal travel. If you have big meats, expect it to kick in later. Other than that, there aren't any.

jerry46765 wrote:Doesn't a three sensor system typically use the trigger on the ring gear of the rear axle?

On the Caprice, the rear sensor plugs directly into a hole in the diff housing and reads a reluctor band on the pinion gear shaft. This would make the swap a huge pain -- you'd have to use the diff from the Caprice, and any tire or rear gear changes would necessitate pulling the pinion and installing a new band. Horrendous.

However, I had seen a trick some 4x4 guys had used for speed sensors that had a 1/8" steel plate fashioned into a two-piece reluctor wheel and bolted to the back of the pinion yoke, with the sensor riding on a bracket attached to the diff webbing, so I thought I'd try it. Not the prettiest thing, but it worked like a champ and it was a heckuva lot easier.

Mark

Interesting…

But the question still stands; does it stop quicker/better with the retrofit application of ABS?

I have never driven this era B body, but wasn't the issue with early ABS that it had large amounts of pedal kickback, which gave a soft pedal feel, and other than preventing wheel lock, didn't improve stopping distance or increased stopping distance?

OEMS added "mythical sensors" on later systems to improve the resolution of anti-locking to prevent overslowing wheels, reduce/minimize kickback, and dramatically decrease stopping distance.

Thanks for posting the details and the photos of the swap.
I would be interested in retrofitting some type of ABS system, but only if there is a performance gain from it.

My buddy has a salvage yard full of cars, and I am going to see if he has a running 90-93 B body, so we can 'test out' the ABS.

Thanks -

Forgot, here is the beginning of a Camaro ABS retrofit, then the updates just stop...

http://nastyz28.com/forum/showthread.php?t=144061

Thanks -

jerry46765 wrote:But the question still stands; does it stop quicker/better with the retrofit application of ABS?

ABS is not a substitute for good brakes. Most definitely anyone's cash is better spent upgrading the braking system before exploring ABS. ABS simply allows the car to maximize the braking ability and driver control by keeping the wheels from locking up and the car from sliding.

jerry46765 wrote:I have never driven this era B body, but wasn't the issue with early ABS that it had large amounts of pedal kickback, which gave a soft pedal feel, and other than preventing wheel lock, didn't improve stopping distance or increased stopping distance?

It feels just like the ABS in my '10 Silverado and the ABS in my wife's Nitro. I personally suspect that a lot of the stigma was because it was relatively new back then, and people were surprised by the pedal feedback and that weird groan. Now everyone knows what to expect. I have heard that GM actually dialed back the entry point of the ABS (i.e. kicks in later) as the years went by due to customer complaints of 'feel'. So counter-intuitively, '91 was better than '96.

FWIW, I also read once where ABS will decrease the stopping distance on dry, wet, and icy pavement, but will actually increase stopping distance on gravel and snow. However, I haven't tried to verify any of that.

jerry46765 wrote:Thanks for posting the details and the photos of the swap.
I would be interested in retrofitting some type of ABS system, but only if there is a performance gain from it.

My buddy has a salvage yard full of cars, and I am going to see if he has a running 90-93 B body, so we can 'test out' the ABS.

All I can say is that it works like it's supposed to, and doesn't feel any different than any other ABS car I've driven. Mostly it just increases safety and control. It can save you and your car in a pinch, but you hope to never need it. I can also say there is a certain peace-of-mind factor.

I guess I'd recommend it if your car is prone to locking up the wheels under hard braking. If it doesn't lock up even under full pedal pressure, then the ABS will never kick in and you'd probably be wasting your time. Mine mostly kicks in when I'm doing something stupid.

If you are game to try it, I can provide more photos and the benefit of hindsight so you can avoid some of the pitfalls I ran into.

Mark

ABS definitely increases stopping distance in snow because if a wheel is sliding it redirects pressure to the other wheels but those other wheels didnt start off with much traction in the first place, this causes another wheel to slide instead of the first 1. Being in canada if u have abs u have to be more careful than u would if u didnt have abs. Thts just in my experience. Not like ur gona be driving in the snow in a classic car LOL

On another forum I'm on, some owners of late model cars don't like the ABS system, and turn it off. They claim that in some instances, the pedal goes down to the floor when the ABS come on on (??) weird..
The wife's Buick has it, as well as the Caddys I've had in recent years.
Just more electronic and hydraulic brake stuff to crap out though.

ya typically the pedal doesn't go to the floor but once the system is activated and ur sliding thru an intersection 9 times out of 10 it just slides right thru unless u pump the pedal ... every time the brake lights shut off the system is deactivated ... so in some scenarios you can stop faster because of those brief times tht the system is deactivated ... i know people tht take out the fuse for the abs especially on a vehicle tht is a stick with traction control

How much power does the system draw? Would it be enough to warrant an alternator or wiring upgrade?

typically there are 2 circuits 1 runs the pump this is usually a 40amp maxi fuse and the other if for the module and its only around 25amp fuse. Not exactingly sure how much it draws but wen the pump is activated on most vehicles u see all the dash lights and stuff dim down ... this is with around 100amp alternator and new battery so if u have a low amp alternator u may wont to swap tht out for something better and use the corresponding alternator wire for the new alternator, but if its around 100amp i wouldnt worry about upgrading the alternator or wiring. Hope this Helps

Many biz jets, and likely transport category types like the airlines, have a system to prevent brake lock-up. The airplanes I worked on called it the "anti-skid" system, and it worked great, without some of the things that happen in cars.
In the cars I've had, the ABS was tied into the traction control. Don't know if this is the common way it's done....

yes this is the most common way it works in a car, the traction control uses the abs sensors to detect a skid/ the speed of each wheel

I've thought about this upgrade alot since posting it & I think that in the end I'm just going to put discs in the rear eventually and maybe upgrade to bigger rotors on all 4's.

ya in my opinion abs wouldnt be practical because the car was never designed to have abs, plus its just too much work tht couldnt be justified. just sharing wat i have learned being a mechanic

geoff528 wrote:ya in my opinion abs wouldnt be practical because the car was never designed to have abs, plus its just too much work tht couldnt be justified. just sharing wat i have learned being a mechanic

While I certainly understand the KISS philosophy (Keep It Stock Stupid), retrofitting newer tech to an older car is the essence of what hot rodding is about. As for myself, I really enjoy researching what is necessary to do a retrofit such as this and make it work right the first time.

As for the car not being designed for ABS, so what? The info provided in just this post has convinced me that this can be a relatively simple retrofit with the possible exception of the brake lines themselves. All you are doing is mixing different generations of Chevy together.

Having said that, I wouldn't do this on a vehicle that you have to have on the road. I would consider doing this with a car that basically sits in the garage because it is a hobby.

this is true just wouldnt do it myself cause like u said maybe do it just to play around with it on a car in the garage, and my car is somethin i wanna drive on a regular basis in good weather, and keepin it pritty stock is wat i like lol i even wanna keep the stock radio

geoff528 wrote:ya in my opinion abs wouldnt be practical because the car was never designed to have abs,

No. Such. Thing.

This is probably the most persistent myth.

The system is simple. The sensor counts the teeth on each wheel (or reluctor) and modulates brake pressure to keep them in line. It knows absolutely nothing about the car it is in. Later designs work in tandem with the traction control simply as a matter of economy -- why design and implement separate sensors for TC when the ones from the ABS system will do nicely? Therefore the factory designs them now as an integrated system.

It's extremely practical, and it does exactly what it's supposed to do. The system has already helped me out when braking hard into turns. But you are correct in that it's a fair amount of work to implement from scratch in a car that never had it.

bigredlaguna wrote: retrofitting newer tech to an older car is the essence of what hot rodding is about. As for myself, I really enjoy researching what is necessary to do a retrofit such as this and make it work right the first time.

As for the car not being designed for ABS, so what? The info provided in just this post has convinced me that this can be a relatively simple retrofit with the possible exception of the brake lines themselves. All you are doing is mixing different generations of Chevy together.

This.