C3 brakes, What to do next??? AAGGHHhhh!!!
04-06-2010, 04:00 PM
#21
Race Director
Thread Starter
I switched to find out what all the hoopla is about. 
Really I remember the deciding moment was when on a cruise, I hit the brakes hard to pull off to a fast approaching side road exit on a backroad highway, my pedal went almost all the way to the floor with not a skreech to be heard from the brakes, and I had what I would have called excellent C3 brakes (SS braided lines, O-ring calipers, new MC, good pads and rotors, nicely bled). Just wasn't happy with the pedal feel when I really needed to step on it.
The switch to hydroboost made my brakes go from a 7-8 feel to a 20 feel on a scale of 1-10. You'll get about 1 inch of pedal travel, then you hit a wall. How hard you apply pressure to that wall is how hard the brakes are modulated. It's FANTASTIC!! It has been tested by some deer running out in front of me one day, right after I did the install, and the performance was top notch.
I don't even hold stock in Hydratech and Im selling it hard.
P.S. I have to add the brakes in all your other cars will feel spongy compared to this.
B.
Really I remember the deciding moment was when on a cruise, I hit the brakes hard to pull off to a fast approaching side road exit on a backroad highway, my pedal went almost all the way to the floor with not a skreech to be heard from the brakes, and I had what I would have called excellent C3 brakes (SS braided lines, O-ring calipers, new MC, good pads and rotors, nicely bled). Just wasn't happy with the pedal feel when I really needed to step on it.
The switch to hydroboost made my brakes go from a 7-8 feel to a 20 feel on a scale of 1-10. You'll get about 1 inch of pedal travel, then you hit a wall. How hard you apply pressure to that wall is how hard the brakes are modulated. It's FANTASTIC!! It has been tested by some deer running out in front of me one day, right after I did the install, and the performance was top notch.
I don't even hold stock in Hydratech and Im selling it hard.
P.S. I have to add the brakes in all your other cars will feel spongy compared to this.
B.
you know what bothers me, is that at one time, with all stock "lower end" parts, it DID stop great, the brakes DID work great....
So why in the heck, even after all the "up graded" parts do my brakes still suck?
very depressing... but everyone that has a hydroboost says the same thing.... GREAT.....
04-06-2010, 04:12 PM
#22
Race Director
Thread Starter
These brakes can be frustrating to say the least (I've done 3 complete C3 brake jobs). And most of us have been pulling wrenches all our lives. All I can say is I had the same problem until I used the Motive Bleeder. I live in Los Gatos if you would like to borrow mine. If my car were not so original, I would do a HydroBoost. Heck, I might anyways...
I looked up you Zip to take you up on it... but you are in northing cal... me southern.... :-(..... I have a power bleeder, and have used it for the M/C before I went wilwood, but the cap/hood that goes over the M/C will not fit the wilwood.. but I went the Wilwood because of the same problem.....
As stated, I will probably go with the hydroboost (I am seeing no other option).... but why cant I have as good of breaks as I had when i purchased her in ~81
I guess C/F durangoboy has rebuilt units and the needed supply list in bradded hoses for all under $300...... good deal... but it just seems I should be able to get good brakes with the upgrades I have already done...
04-06-2010, 04:32 PM
#23
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Paul it wont have anything to do with your vacuum level, poor vacuum would give you a firmer pedal, not a softer one.
If I can recap.
You fitted mew master, callipers, rotors and pads and braided lines?
You have what you describe as a spongy pedal?
So you have a consistently 'long' pedal?
If you pump the pedal does it pump up and become firmer?
Have you replaced any of the lard lines?
Have you checked the braided lines for any bulging while someone applies pressure to the brake pedal?
When you brake hard does the car pull up straight?
Can you feel any particular wheel/s braking better than the others?
Have you checked the rotors for run-out in case your getting pad 'knock off'?
I like a challenge
If I can recap.
You fitted mew master, callipers, rotors and pads and braided lines?
You have what you describe as a spongy pedal?
So you have a consistently 'long' pedal?
If you pump the pedal does it pump up and become firmer?
Have you replaced any of the lard lines?
Have you checked the braided lines for any bulging while someone applies pressure to the brake pedal?
When you brake hard does the car pull up straight?
Can you feel any particular wheel/s braking better than the others?
Have you checked the rotors for run-out in case your getting pad 'knock off'?
I like a challenge
04-06-2010, 04:41 PM
#24
Race Director
Thread Starter
Paul it wont have anything to do with your vacuum level, poor vacuum would give you a firmer pedal, not a softer one.
If I can recap.
1. You fitted mew master, callipers, rotors and pads and braided lines?
2. You have what you describe as a spongy pedal?
3. So you have a consistently 'long' pedal?
4. If you pump the pedal does it pump up and become firmer?
5. Have you replaced any of the lard lines?
6. Have you checked the braided lines for any bulging while someone applies pressure to the brake pedal?
7. When you brake hard does the car pull up straight?
8. Can you feel any particular wheel/s braking better than the others?
9. Have you checked the rotors for run-out in case your getting pad 'knock off'?
10. I like a challenge
If I can recap.
1. You fitted mew master, callipers, rotors and pads and braided lines?
2. You have what you describe as a spongy pedal?
3. So you have a consistently 'long' pedal?
4. If you pump the pedal does it pump up and become firmer?
5. Have you replaced any of the lard lines?
6. Have you checked the braided lines for any bulging while someone applies pressure to the brake pedal?
7. When you brake hard does the car pull up straight?
8. Can you feel any particular wheel/s braking better than the others?
9. Have you checked the rotors for run-out in case your getting pad 'knock off'?
10. I like a challenge
2. yes
3. about 1" of peddle travel... but spongy for about another 1" then the wall and no more increasing force.
4. no
5. no
6. new... and no bulging..
7. yes, straight
8. I think much more stopping power from front... a lot (like 10 times) more brake dust up front... so I am thinking back is more of the problem???/ but its a guess to be honest
9. yes... they run STRAIGHT!
10. you got one.... no one has been able to figure this out,,,, not a single brake shop in town... not even ME!!!!! lol
04-06-2010, 04:47 PM
#25
04-06-2010, 04:50 PM
#26
Race Director
Also, can you brake hard enough to lock the wheels?
04-06-2010, 04:52 PM
#27
Race Director
Thread Starter
have you seen this cause my problem?
I would fly to Canada to fix this problem!!!
thx... p:-)
PS... the USA should have won the hockey game!!!!!!!
Last edited by pauldana; 04-06-2010 at 05:06 PM.
04-06-2010, 04:53 PM
#28
Melting Slicks
When you bled the rears, did you do the inners or outers first? I seem to remember being told whilst it really doesnt matter what caliper you bleed first, it is important to bleed the inners on the rears first, ie the bleeders nearest to where the flexible line goes in.
Also, when using a pressure bleeder, make sure the pressure is not too high as it can sometimes induce small amounts of air in to the fluid...not good.
As has been said before, a gentle tap of the calipers with a mallet helps to dislodge any bubbles trapped.
Good luck.
Also, when using a pressure bleeder, make sure the pressure is not too high as it can sometimes induce small amounts of air in to the fluid...not good.
As has been said before, a gentle tap of the calipers with a mallet helps to dislodge any bubbles trapped.
Good luck.
04-06-2010, 04:55 PM
#29
Race Director
Thread Starter
front sometimes... cant get the back ones to lock...
04-06-2010, 04:58 PM
#30
Melting Slicks
04-06-2010, 05:00 PM
#31
Race Director
Thread Starter
When you bled the rears, did you do the inners or outers first? I seem to remember being told whilst it really doesnt matter what caliper you bleed first, it is important to bleed the inners on the rears first, ie the bleeders nearest to where the flexible line goes in.
Also, when using a pressure bleeder, make sure the pressure is not too high as it can sometimes induce small amounts of air in to the fluid...not good.
As has been said before, a gentle tap of the calipers with a mallet helps to dislodge any bubbles trapped.
Good luck.
Also, when using a pressure bleeder, make sure the pressure is not too high as it can sometimes induce small amounts of air in to the fluid...not good.
As has been said before, a gentle tap of the calipers with a mallet helps to dislodge any bubbles trapped.
Good luck.
my pressure bleeder I put 15psi in the bottom....
haven't used the mallet.... maybe because I'm afraid i will take it to the rest of the car!!!!!! lol...
04-06-2010, 05:10 PM
#33
Melting Slicks
OK, real dumb question.. have you checked all the brake unions for tightness?
When I re did all the hard lines on my 75, I had a pig of a job bleeding the rears. Although it didnt leak, one of the unions on the rear brake block was loose and was letting air in whist I was getting the fluid out at the caliper
I was almost at the point of throwing my tools around the garage before I found it!
When I re did all the hard lines on my 75, I had a pig of a job bleeding the rears. Although it didnt leak, one of the unions on the rear brake block was loose and was letting air in whist I was getting the fluid out at the caliper
I was almost at the point of throwing my tools around the garage before I found it!
04-06-2010, 05:17 PM
#34
Race Director
Thread Starter
OK, real dumb question.. have you checked all the brake unions for tightness?
When I re did all the hard lines on my 75, I had a pig of a job bleeding the rears. Although it didnt leak, one of the unions on the rear brake block was loose and was letting air in whist I was getting the fluid out at the caliper
I was almost at the point of throwing my tools around the garage before I found it!
When I re did all the hard lines on my 75, I had a pig of a job bleeding the rears. Although it didnt leak, one of the unions on the rear brake block was loose and was letting air in whist I was getting the fluid out at the caliper
I was almost at the point of throwing my tools around the garage before I found it!
and that is just about how i feel.... now....
04-06-2010, 05:22 PM
#35
Team Owner
Paul, I can almost GUAR AN FREEKING TEE YOU, you pop your master cylinder off the booster, hopefully you have decent line length....
as it has to move slightly forward, and replace that sucky stock brake booster with a HYDROBOOST.....
I been driving GM/vacuum assisted cars for decades, and so they all SUCK, vacuum sux, period....end of conversation...
put on a HB setup and then put that same exact m/cyl on the HB unit, and then be prepared for a serious STOP, even with some oil foam in the power steering side of the circuit....which settles out overnight with use....
that is what I did, the complaint is old with me, VERY old, the brakes on ANY vac assisted car are very soft, and the sharks are more prone to that sick feeling than most other cars....
BUT when doing the DAY/NIGHT comparo without touching a brake line, going to HB....that shark stood on it's NOSE for the very first time.....
all else is
and anyone defending vacuum boosters on a shark is just plain used to the feel of inadequate brakes....period
CASE CLOSED......
as it has to move slightly forward, and replace that sucky stock brake booster with a HYDROBOOST.....
I been driving GM/vacuum assisted cars for decades, and so they all SUCK, vacuum sux, period....end of conversation...
put on a HB setup and then put that same exact m/cyl on the HB unit, and then be prepared for a serious STOP, even with some oil foam in the power steering side of the circuit....which settles out overnight with use....
that is what I did, the complaint is old with me, VERY old, the brakes on ANY vac assisted car are very soft, and the sharks are more prone to that sick feeling than most other cars....
BUT when doing the DAY/NIGHT comparo without touching a brake line, going to HB....that shark stood on it's NOSE for the very first time.....
all else is
and anyone defending vacuum boosters on a shark is just plain used to the feel of inadequate brakes....periodCASE CLOSED......
04-06-2010, 05:48 PM
#36
Race Director
It could also be that the MC is not matched to your car. You're sure it's 1 1/8" bore? And that it has enough volume for your calipers (i.e. MC piston is not bottoming out)?
I know you said you replaced the booster, but just because it's new doesn't mean it can't be broken.
Also, if you have sticky tires and hard pads you may find you need a 1" bore MC to make the brakes work correctly as the 1 1/8" line pressure was marginal to begin with. The 1" MC was what came on manual brake cars so it's easy to find.
I went with a 1" MC on my '71 even though it has power brakes as it made for a nicer (easier) pedal and allowed me to easily lock the wheels even with sticky tires.
04-06-2010, 06:06 PM
#37
Race Director
Thread Starter
Paul, I can almost GUAR AN FREEKING TEE YOU, you pop your master cylinder off the booster, hopefully you have decent line length....
as it has to move slightly forward, and replace that sucky stock brake booster with a HYDROBOOST.....
I been driving GM/vacuum assisted cars for decades, and so they all SUCK, vacuum sux, period....end of conversation...
put on a HB setup and then put that same exact m/cyl on the HB unit, and then be prepared for a serious STOP, even with some oil foam in the power steering side of the circuit....which settles out overnight with use....
that is what I did, the complaint is old with me, VERY old, the brakes on ANY vac assisted car are very soft, and the sharks are more prone to that sick feeling than most other cars....
BUT when doing the DAY/NIGHT comparo without touching a brake line, going to HB....that shark stood on it's NOSE for the very first time.....
all else is and anyone defending vacuum boosters on a shark is just plain used to the feel of inadequate brakes....period
CASE CLOSED......
as it has to move slightly forward, and replace that sucky stock brake booster with a HYDROBOOST.....
I been driving GM/vacuum assisted cars for decades, and so they all SUCK, vacuum sux, period....end of conversation...
put on a HB setup and then put that same exact m/cyl on the HB unit, and then be prepared for a serious STOP, even with some oil foam in the power steering side of the circuit....which settles out overnight with use....
that is what I did, the complaint is old with me, VERY old, the brakes on ANY vac assisted car are very soft, and the sharks are more prone to that sick feeling than most other cars....
BUT when doing the DAY/NIGHT comparo without touching a brake line, going to HB....that shark stood on it's NOSE for the very first time.....
all else is
and anyone defending vacuum boosters on a shark is just plain used to the feel of inadequate brakes....periodCASE CLOSED......
Then your problem is NOT air in the lines. You have either a bad booster or blockage (combination valve).
blockage (combination valve) where? the switch/valve?
It could also be that the MC is not matched to your car. You're sure it's 1 1/8" bore? And that it has enough volume for your calipers (i.e. MC piston is not bottoming out)?
1 1/8 100% Wilwood
I know you said you replaced the booster, but just because it's new doesn't mean it can't be broken.
yea... i agree, but for how i described the problem?
Also, if you have sticky tires and hard pads you may find you need a 1" bore MC to make the brakes work correctly as the 1 1/8" line pressure was marginal to begin with. The 1" MC was what came on manual brake cars so it's easy to find.
junk 15"
I went with a 1" MC on my '71 even though it has power brakes as it made for a nicer (easier) pedal and allowed me to easily lock the wheels even with sticky tires.
blockage (combination valve) where? the switch/valve?
It could also be that the MC is not matched to your car. You're sure it's 1 1/8" bore? And that it has enough volume for your calipers (i.e. MC piston is not bottoming out)?
1 1/8 100% Wilwood
I know you said you replaced the booster, but just because it's new doesn't mean it can't be broken.
yea... i agree, but for how i described the problem?
Also, if you have sticky tires and hard pads you may find you need a 1" bore MC to make the brakes work correctly as the 1 1/8" line pressure was marginal to begin with. The 1" MC was what came on manual brake cars so it's easy to find.
junk 15"
I went with a 1" MC on my '71 even though it has power brakes as it made for a nicer (easier) pedal and allowed me to easily lock the wheels even with sticky tires.
04-06-2010, 06:18 PM
#38
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When you say you have an inch of travel, then another spongy inch of travel, does the initial movement seem to do anything?
If not it's sounding like there might be a mismatch of operating rod lengths in the pedal/booster/MC combination.
Last edited by Golden; 04-06-2010 at 06:31 PM.
04-06-2010, 06:29 PM
#39
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Hi!
Try this:
1. Use master cylinder with bleeders
2. Check the length of the push rod. It is very important that the push rod is not too long. It should be not too long, not too short. Look on the schemata/ operating mode of the master cylinder.
I have done the job with new front calippers, new flexible brake lines, boster, master cylinder. Bench bleeding, 2x bleeding with the bleeders in master cylinder, 2x bleeding of the calippers (traditionally
pedal pump metod : fast down , very slow up).
100% equal brake effect front/ rear - Tested.
Try this:
1. Use master cylinder with bleeders
2. Check the length of the push rod. It is very important that the push rod is not too long. It should be not too long, not too short. Look on the schemata/ operating mode of the master cylinder.
I have done the job with new front calippers, new flexible brake lines, boster, master cylinder. Bench bleeding, 2x bleeding with the bleeders in master cylinder, 2x bleeding of the calippers (traditionally
pedal pump metod : fast down , very slow up).
100% equal brake effect front/ rear - Tested.
04-06-2010, 06:31 PM
#40
Race Director
Thread Starter
Well done for knowing what 'lard lines' are
When you say you have an inch of travel, then another spongy inch of travel, does the initial movement seem to do anything?
If not it's sounding like there might be a mismatch of operating rod lengths in the pedal/booster/MC combination.
When you say you have an inch of travel, then another spongy inch of travel, does the initial movement seem to do anything?
If not it's sounding like there might be a mismatch of operating rod lengths in the pedal/booster/MC combination.
.... actually tried to do a quick search... duh!!ok... stock peddle rod... booster??? should be stock, but it has been replaced..... M/C 3rd on so far, this one is a Wilwood from Wilwood....
