how 2 check 88 abs?
Thread Starter
Safety Car
Joined: Jul 2004
Posts: 3,845
Likes: 30
how 2 check 88 abs?
greetings all,
i have a contiuing problem with my 88's brakes. they just don't grab for $_it!...fred flintstone had better brakes. i have;
1)... replaced all pads with recomended pads,
2)... flushed + bled all brakes, lines, etc more than 4x's already,
3)... replaced brake hoses with stainless,
4)... good known master cylinder,
5)... have had on 3 other m/c's and no difference in braking,
6)....calipers don't appear to be hanging up,
7)....used a "miti-vac" to draw vacuum on brake booster and check
valve and it "held",
8)... rotors are fine, no scores, etc.,
9)... broke in new pads as recomendend,
10)...no spongy brakes or hard pedal or excessive pedal travel,
11)...correct brake fluid,
12)...abs system (test) initializes properly when backing, etc
13)...no "hissing sound" from booster,
i am running out of ideas here! i imagine that if the abs were bad, it would through some codes but, none "thrown"....
...any ideas or other test methods?...thanks!
i have a contiuing problem with my 88's brakes. they just don't grab for $_it!...fred flintstone had better brakes. i have;
1)... replaced all pads with recomended pads,
2)... flushed + bled all brakes, lines, etc more than 4x's already,
3)... replaced brake hoses with stainless,
4)... good known master cylinder,
5)... have had on 3 other m/c's and no difference in braking,
6)....calipers don't appear to be hanging up,
7)....used a "miti-vac" to draw vacuum on brake booster and check
valve and it "held",
8)... rotors are fine, no scores, etc.,
9)... broke in new pads as recomendend,
10)...no spongy brakes or hard pedal or excessive pedal travel,
11)...correct brake fluid,
12)...abs system (test) initializes properly when backing, etc
13)...no "hissing sound" from booster,
i am running out of ideas here! i imagine that if the abs were bad, it would through some codes but, none "thrown"....
...any ideas or other test methods?...thanks!
Team Owner
Joined: Dec 1999
Posts: 34,873
Likes: 487
From: Lacey WA RVN 68-69
NCM Sinkhole Donor
You could have a glazed surface on the rotor face from a previous brake pad compound. You didn't say how new the rotors are but you might want to have them turned just enough to get a new surface on them. While the factory service manual doesn't recommend turning the rotors, you might give it a try. Re-bed the pads after turning or replacement.
Replacement rotors are not that expensive anyway so the cost of new rotors may be worth doing. It sounds like you have pretty much gone thru the rest of the system.
Replacement rotors are not that expensive anyway so the cost of new rotors may be worth doing. It sounds like you have pretty much gone thru the rest of the system.
Thread Starter
Safety Car
Joined: Jul 2004
Posts: 3,845
Likes: 30
Originally Posted by c4cruiser
You could have a glazed surface on the rotor face from a previous brake pad compound. You didn't say how new the rotors are but you might want to have them turned just enough to get a new surface on them. While the factory service manual doesn't recommend turning the rotors, you might give it a try. Re-bed the pads after turning or replacement.
Replacement rotors are not that expensive anyway so the cost of new rotors may be worth doing. It sounds like you have pretty much gone thru the rest of the system.
Replacement rotors are not that expensive anyway so the cost of new rotors may be worth doing. It sounds like you have pretty much gone thru the rest of the system.
re rotors;......."8)... rotors are fine, no scores, etc.,"
(i am unsure how new or old the rotors are)
would "glazed rotors make that much of a difference in braking?
Race Director
Joined: Jun 2004
Posts: 13,960
Likes: 707
From: WI
" how 2 check 88 abs? "
Drive around 40 MPH, stand on the brake pedal with both feet. You should hear a rapid sound (BIZT! BIZT!) similar to what you hear when the ABS first initalizes. That whirling sound behind the drivers seat, when you first start driving. You'll know it if it's working! Also pressing the pedal very lightly in slippery terrain will activate it. I drove across my driveway in snow once this winter moving the car out of storage because I needed the room for a bit. The ABS was funny it activated so much!
Drive around 40 MPH, stand on the brake pedal with both feet. You should hear a rapid sound (BIZT! BIZT!) similar to what you hear when the ABS first initalizes. That whirling sound behind the drivers seat, when you first start driving. You'll know it if it's working! Also pressing the pedal very lightly in slippery terrain will activate it. I drove across my driveway in snow once this winter moving the car out of storage because I needed the room for a bit. The ABS was funny it activated so much!
Thread Starter
Safety Car
Joined: Jul 2004
Posts: 3,845
Likes: 30
Originally Posted by Aardwolf
" how 2 check 88 abs? "
Drive around 40 MPH, stand on the brake pedal with both feet. You should hear a rapid sound (BIZT! BIZT!) similar to what you hear when the ABS first initalizes. That whirling sound behind the drivers seat, when you first start driving. You'll know it if it's working! Also pressing the pedal very lightly in slippery terrain will activate it. I drove across my driveway in snow once this winter moving the car out of storage because I needed the room for a bit. The ABS was funny it activated so much!
Drive around 40 MPH, stand on the brake pedal with both feet. You should hear a rapid sound (BIZT! BIZT!) similar to what you hear when the ABS first initalizes. That whirling sound behind the drivers seat, when you first start driving. You'll know it if it's working! Also pressing the pedal very lightly in slippery terrain will activate it. I drove across my driveway in snow once this winter moving the car out of storage because I needed the room for a bit. The ABS was funny it activated so much!
he believes the rotors are glazed as they are very "shiney". there is no place around me that turns rotors anymore due to strict epa guidelines so, he sdvised with instructions as to how i can break the glaze on my rotors and pads which i will try by the week end. the abs is throwing no codes at all at this time either.
Team Owner
Joined: Dec 1999
Posts: 34,873
Likes: 487
From: Lacey WA RVN 68-69
NCM Sinkhole Donor
Most of the shops around here have brake lathes and where I work, we even turn new rotors to insure they are not warped. I don't know what "EPA Guidelines" he is referring to but turning rotors and drums is still a common part of brake overhauls.
But most rotors are manufactured with little room for turning down the thickness. Rotors are stamped with a value that represents the minimum safe thickness and reputable shops will not turn rotors and drum if the are close to the minimum spec. Stock type rotors are cheap anyway.
But most rotors are manufactured with little room for turning down the thickness. Rotors are stamped with a value that represents the minimum safe thickness and reputable shops will not turn rotors and drum if the are close to the minimum spec. Stock type rotors are cheap anyway.
Thread Starter
Safety Car
Joined: Jul 2004
Posts: 3,845
Likes: 30
Originally Posted by c4cruiser
Most of the shops around here have brake lathes and where I work, we even turn new rotors to insure they are not warped. I don't know what "EPA Guidelines" he is referring to but turning rotors and drums is still a common part of brake overhauls.
But most rotors are manufactured with little room for turning down the thickness. Rotors are stamped with a value that represents the minimum safe thickness and reputable shops will not turn rotors and drum if the are close to the minimum spec. Stock type rotors are cheap anyway.
But most rotors are manufactured with little room for turning down the thickness. Rotors are stamped with a value that represents the minimum safe thickness and reputable shops will not turn rotors and drum if the are close to the minimum spec. Stock type rotors are cheap anyway.
he explained that while turning the rotors, brake dust - particles, imbedded or otherwise, would be released into the air, etc etc etc. .
three local shops told me this and the last shop "sealed" it for me.
i know that there some dealers whom probably turn rotors and some remaining shops but, i am unaware if there is a time limit for them to come into compliance.
i plan on writing the epa and asking for not only clarification (if any needed), but, a copy of the directive of such restriction(s)....
Pro
Joined: Jun 2004
Posts: 646
Likes: 0
From: Santee Ca
They don't have any rules like that in Calif. and we are one of the most strictest when it comes to stuff like that. I can go down to my local Kragen and get rotors/drums turned for $5 a piece. And they just turn them behind the parts shelves.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Team Owner
Joined: Dec 1999
Posts: 34,873
Likes: 487
From: Lacey WA RVN 68-69
NCM Sinkhole Donor
Back when brake pad and shoes contained asbestos, there were some concerns about the asbestos dust being breathed in. But asbestos has not been used in brake compunds for years.
In any event, EPA Guidelines are federal requirements and all 50 states would have had to comply with these guidelines. It sounds like the guy wants to sell new parts and not be bothered with setting up the machine, keeping it in good operating condition, and maybe having somebody who know how to run it properly.
The biggest issue with a brake lathe is sweeping up the iron particles afterwards.
In any event, EPA Guidelines are federal requirements and all 50 states would have had to comply with these guidelines. It sounds like the guy wants to sell new parts and not be bothered with setting up the machine, keeping it in good operating condition, and maybe having somebody who know how to run it properly.
The biggest issue with a brake lathe is sweeping up the iron particles afterwards.
Thread Starter
Safety Car
Joined: Jul 2004
Posts: 3,845
Likes: 30
Originally Posted by c4cruiser
Back when brake pad and shoes contained asbestos, there were some concerns about the asbestos dust being breathed in. But asbestos has not been used in brake compunds for years.
In any event, EPA Guidelines are federal requirements and all 50 states would have had to comply with these guidelines. It sounds like the guy wants to sell new parts and not be bothered with setting up the machine, keeping it in good operating condition, and maybe having somebody who know how to run it properly.
The biggest issue with a brake lathe is sweeping up the iron particles afterwards.
In any event, EPA Guidelines are federal requirements and all 50 states would have had to comply with these guidelines. It sounds like the guy wants to sell new parts and not be bothered with setting up the machine, keeping it in good operating condition, and maybe having somebody who know how to run it properly.
The biggest issue with a brake lathe is sweeping up the iron particles afterwards.
Burning Brakes
Joined: Jan 2006
Posts: 854
Likes: 1
From: The burbs of Denver CO
Mail Man, I can't see where you are from, but I have never heard of the epa getting involved in machine shop grinding of rotors. In fact, in Colorado every Pep Boys, Checker, Napa, Target, etc. etc. turns rotors and drums.
If your rotors are glazed, no doubt so are the pads. Throw the old pads away, get the rotors turned, then be careful testing them out - you could become a hood ornament!
It sounds like you have checked everything else.
If your rotors are glazed, no doubt so are the pads. Throw the old pads away, get the rotors turned, then be careful testing them out - you could become a hood ornament!
It sounds like you have checked everything else.
Thread Starter
Safety Car
Joined: Jul 2004
Posts: 3,845
Likes: 30
Originally Posted by thebeerman
Mail Man, I can't see where you are from, but I have never heard of the epa getting involved in machine shop grinding of rotors. In fact, in Colorado every Pep Boys, Checker, Napa, Target, etc. etc. turns rotors and drums.
If your rotors are glazed, no doubt so are the pads. Throw the old pads away, get the rotors turned, then be careful testing them out - you could become a hood ornament! It sounds like you have checked everything else.
If your rotors are glazed, no doubt so are the pads. Throw the old pads away, get the rotors turned, then be careful testing them out - you could become a hood ornament!
It sounds like you have checked everything else.moving on....the rotors are really the only thing left. i am leaning towards a glazing of both the pads and the rotors but, i never thought it could be this bad and make my braking almost non-existent!
Burning Brakes
Joined: Jan 2006
Posts: 854
Likes: 1
From: The burbs of Denver CO
I live in the Denver area, and work in the mountains. It is very common around here (glazed pads and rotors) because people use their brakes a lot to slow down without coming to a stop. Unfortunately, the better the brake pad (longer lasting) the more prone to glazing because they use different compounds that last longer but glaze faster. Sometimes just doing a couple of hard braking passes, coming to a full stop, will burn the glaze off, but it sounds like your are pretty well gone. When you hear the glazed pads, it sounds like you are gouging the rotors and you will think the pads are shot, but when you pull the wheel you find there is nothing wrong with them. Since it is such an easy job to do brakes on the vette, and pads are readily available and cheap, you might even consider using the softer pads.
Le Mans Master
Joined: Feb 2000
Posts: 9,715
Likes: 27
From: Kempner Texas
Originally Posted by Aardwolf
" how 2 check 88 abs? "
Drive around 40 MPH, stand on the brake pedal with both feet. You should hear a rapid sound (BIZT! BIZT!) similar to what you hear when the ABS first initalizes. That whirling sound behind the drivers seat, when you first start driving. You'll know it if it's working! Also pressing the pedal very lightly in slippery terrain will activate it. I drove across my driveway in snow once this winter moving the car out of storage because I needed the room for a bit. The ABS was funny it activated so much!
Drive around 40 MPH, stand on the brake pedal with both feet. You should hear a rapid sound (BIZT! BIZT!) similar to what you hear when the ABS first initalizes. That whirling sound behind the drivers seat, when you first start driving. You'll know it if it's working! Also pressing the pedal very lightly in slippery terrain will activate it. I drove across my driveway in snow once this winter moving the car out of storage because I needed the room for a bit. The ABS was funny it activated so much!
Jake
Thread Starter
Safety Car
Joined: Jul 2004
Posts: 3,845
Likes: 30
Originally Posted by thebeerman
I live in the Denver area, and work in the mountains. It is very common around here (glazed pads and rotors) because people use their brakes a lot to slow down without coming to a stop. Unfortunately, the better the brake pad (longer lasting) the more prone to glazing because they use different compounds that last longer but glaze faster. Sometimes just doing a couple of hard braking passes, coming to a full stop, will burn the glaze off, but it sounds like your are pretty well gone. When you hear the glazed pads, it sounds like you are gouging the rotors and you will think the pads are shot, but when you pull the wheel you find there is nothing wrong with them. Since it is such an easy job to do brakes on the vette, and pads are readily available and cheap, you might even consider using the softer pads.
it was raining here a bit today so, i will test the brakes tomorrow.
i "broke the glaze" on the pads and rotors as directed by a machine shop as a test. i did notice that the back rotors had what appeared to be "pad material' imbeded into the rotors that was almost impossible to "remove". granted, what i did is only a test at this point. i will let ya know!
Le Mans Master
Joined: Feb 2000
Posts: 9,715
Likes: 27
From: Kempner Texas
Originally Posted by Da Mail Man
thanks for the reply...i have your everyday stock replacement pads all the way around. i hear no sounds from the wheels/pads while braking or otherwise except when they are wet after washing the car. then, when i slowly start (less then 3 mph) moving and apply the brakes, it sounds like a deep groan while stopping.
it was raining here a bit today so, i will test the brakes tomorrow.
i "broke the glaze" on the pads and rotors as directed by a machine shop as a test. i did notice that the back rotors had what appeared to be "pad material' imbeded into the rotors that was almost impossible to "remove". granted, what i did is only a test at this point. i will let ya know!
it was raining here a bit today so, i will test the brakes tomorrow.
i "broke the glaze" on the pads and rotors as directed by a machine shop as a test. i did notice that the back rotors had what appeared to be "pad material' imbeded into the rotors that was almost impossible to "remove". granted, what i did is only a test at this point. i will let ya know!
Seems that exhaust heat, especially when headers are installed, cause the plastic booster to crack. I even read about that happening in one of the Vette mags (as luck would have it I read this AFTER I solved my braking problem) and they fashioned a heat shield to go on the booster between the engine and the booster.
Just my thoughts.
Jake
Thread Starter
Safety Car
Joined: Jul 2004
Posts: 3,845
Likes: 30
Originally Posted by JAKE
I know you already checked the booster, but make SURE it isn't cracked. I had a similar braking problem and it turned out to be that my plastic booster was cracked on the engine side in a location I couldn't see until I took the booster off.
Seems that exhaust heat, especially when headers are installed, cause the plastic booster to crack. I even read about that happening in one of the Vette mags (as luck would have it I read this AFTER I solved my braking problem) and they fashioned a heat shield to go on the booster between the engine and the booster.
Just my thoughts.
Jake
Seems that exhaust heat, especially when headers are installed, cause the plastic booster to crack. I even read about that happening in one of the Vette mags (as luck would have it I read this AFTER I solved my braking problem) and they fashioned a heat shield to go on the booster between the engine and the booster.
Just my thoughts.
Jake
i have 2 extra spare boosters in the garage which are good, so i "plugged those into the engine" and the idle and the engines "reaction" to those are identical. i have rulled the booster out as a possibility.
Le Mans Master
Joined: Feb 2000
Posts: 9,715
Likes: 27
From: Kempner Texas
Any chance the vacuum connection at the plenum/booster is leaking?
How much pedal travel do you have? I had to shim the booster to M/C rod to take up the slack in my pedal after changing boosters.
BTW, when my ABS died last year, my brakes continued to function normally, just as GM says they would. I just didn't have ABS functionality.
Jake
How much pedal travel do you have? I had to shim the booster to M/C rod to take up the slack in my pedal after changing boosters.
BTW, when my ABS died last year, my brakes continued to function normally, just as GM says they would. I just didn't have ABS functionality.
Jake
Thread Starter
Safety Car
Joined: Jul 2004
Posts: 3,845
Likes: 30
Originally Posted by JAKE
Any chance the vacuum connection at the plenum/booster is leaking?
How much pedal travel do you have? I had to shim the booster to M/C rod to take up the slack in my pedal after changing boosters.
BTW, when my ABS died last year, my brakes continued to function normally, just as GM says they would. I just didn't have ABS functionality.
Jake
How much pedal travel do you have? I had to shim the booster to M/C rod to take up the slack in my pedal after changing boosters.
BTW, when my ABS died last year, my brakes continued to function normally, just as GM says they would. I just didn't have ABS functionality.
Jake
Last edited by Da Mail Man; Apr 12, 2006 at 07:23 PM. Reason: left something out