low brake after bleeding brakes
Thread Starter
Heel & Toe
Joined: Jul 2020
Posts: 15
Likes: 2
low brake after bleeding brakes
i have a 77 vette. I took it out of storage and the brakes were soft. i replaced the master cylinder and i have replaced 1 caliper.
i pressure bleed and and put in new fluid. brakes set up hard and work for a short period of time. while driving the brake pedal is hard and then the next time i step on the brakes it goes soft again.
there is no fluid leakage anywhere.
does anybody have any suggestions.
thanks
randy
i pressure bleed and and put in new fluid. brakes set up hard and work for a short period of time. while driving the brake pedal is hard and then the next time i step on the brakes it goes soft again.
there is no fluid leakage anywhere.
does anybody have any suggestions.
thanks
randy
Race Director
Joined: May 2006
Posts: 18,742
Likes: 2,583
Did you do both inner and outer bleed screws in the back?
Did you bleed RR, LR, RF,LF?
Did you tap the calipers with a hammer as you bled them?
Did you check rotor runout?
Did you bleed RR, LR, RF,LF?
Did you tap the calipers with a hammer as you bled them?
Did you check rotor runout?
Last edited by MelWff; Jul 23, 2020 at 05:24 PM.
Thread Starter
Heel & Toe
Joined: Jul 2020
Posts: 15
Likes: 2
the only thing i didn't do was tap the calipers. i can get the brakes with a hard pedal and they work fine sometimes 6-7 times then soft pedal. i rebleed and then they will work only 2 or 3 times. i am up to 7 bleeds and every time they work for a various number of braking and then the next brake is soft pedal. i noticed that the RF is the only caliper that stays working.
there is no sign of fluid anywhere.
is there some way that air is being sucked in from somewhere.
there is no sign of fluid anywhere.
is there some way that air is being sucked in from somewhere.
Melting Slicks
Joined: Jun 2011
Posts: 3,116
Likes: 598
i have a 77 vette. I took it out of storage and the brakes were soft. i replaced the master cylinder and i have replaced 1 caliper.
i pressure bleed and and put in new fluid. brakes set up hard and work for a short period of time. while driving the brake pedal is hard and then the next time i step on the brakes it goes soft again.
there is no fluid leakage anywhere.
does anybody have any suggestions.
thanks
randy
i pressure bleed and and put in new fluid. brakes set up hard and work for a short period of time. while driving the brake pedal is hard and then the next time i step on the brakes it goes soft again.
there is no fluid leakage anywhere.
does anybody have any suggestions.
thanks
randy
https://www.corvetteforum.com/forums...-cylinder.html
Also another reason this could happen is the rotor runout is pushing the caliper piston back into the caliper, then the next time you press the brake pedal the first part of the braking is to reseat the pads on the rotor (soft pedal). So if you get a soft pedal on the first press and better pedal on the second press I would check your rotor runout and go from there.
Last edited by cagotzmann; Jul 23, 2020 at 08:16 PM.
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Thread Starter
Heel & Toe
Joined: Jul 2020
Posts: 15
Likes: 2
i found out it was a defective left front caliper.
now i have been having a problem locating a caliper that is not defective.
I am now on number 5. i have used a variety of different remanufactured brands like Raybestos, A C Delco etc and they have all failed.
has anyone encountered this isssue. it is only with the left front.
does anyone know where i can get a new original corvette caliper.
thanks
Randy
now i have been having a problem locating a caliper that is not defective.
I am now on number 5. i have used a variety of different remanufactured brands like Raybestos, A C Delco etc and they have all failed.
has anyone encountered this isssue. it is only with the left front.
does anyone know where i can get a new original corvette caliper.
thanks
Randy
Burning Brakes
Joined: Oct 2012
Posts: 1,152
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Le Mans Master
Joined: Aug 2005
Posts: 6,541
Likes: 1,975
From: Temple Terrace Florida
If your old calipers have been sleeved in stainless steel, buy an O-ring kit and rebuild them yourself. It is easy to do with hand tools and a torque wrench. If they have not been sleeved, buy a sleeved set from one of the vendors. Jerry
Thread Starter
Heel & Toe
Joined: Jul 2020
Posts: 15
Likes: 2
i have found 2 styles of new calipers ie not remanufactured. they are stainless steel sleeves and one type has o-ring and the other type has lip seal. they are almost the same price, the lip seal is $15 more. not a big difference, if it is a better product.
my vette is a 1977.
does anyone have experience with either type and if so which is considered the best and most reliable and will either style fit my car.
thanks
randy
my vette is a 1977.
does anyone have experience with either type and if so which is considered the best and most reliable and will either style fit my car.
thanks
randy
Melting Slicks
Joined: Jun 2011
Posts: 3,116
Likes: 598
i have found 2 styles of new calipers ie not remanufactured. they are stainless steel sleeves and one type has o-ring and the other type has lip seal. they are almost the same price, the lip seal is $15 more. not a big difference, if it is a better product.
my vette is a 1977.
does anyone have experience with either type and if so which is considered the best and most reliable and will either style fit my car.
thanks
randy
my vette is a 1977.
does anyone have experience with either type and if so which is considered the best and most reliable and will either style fit my car.
thanks
randy
here is my supply of failed units both lip or o-ring.
Top group are lonestar brand the buttom stack is lip seal delco brand. Are are Stainless Steel sleeves. But you will notice the wilwood boxes (old lip seal calipers inside)
I have switch to using wilwood calipers. At most the calipers lasted 3 years. but 1 failed every year.
Now to be fare my car is used for track days so they are pushed to the limits.
But this has shown the difference in quality when tested. The seal material used in todays new / rebuilds are poor compared to wilwood and poor compared to what we got from the 90's to 2005 ish.
Le Mans Master
Joined: Aug 2005
Posts: 6,541
Likes: 1,975
From: Temple Terrace Florida
I installed O-ring pistons and seals on my 66 and 68 coupes. I have also rebuilt a number of others for friends. Many years and miles, no leaks. If you are looking for an opinion, I would go with O-ring pistons with Delco Moraine calipers. Some of the vendors are offering "no name" calipers manufactured off shore. Jerry