Help with Brakes Please.....

Pasta Power · #1 (**permalink**) 01-01-2009, 10:09 AM

After reading through the past posts on brakes, and trying various bleeding proceedures I still have mushey brakes, meaning when I mash the peddle I cannot get them to lock up they just fade to a stop, kinda scarry at times. I purchased my car from CRI, 18 years ago and I only have 2500 miles on it. My question is, was their a change made to the power booster, and master cylnder since I purchased mine. I sourced these items from Mainly Classics after getting screwed by CRI, I was told they were for a 1974-78 Mustang II if their was a change can someone please provde the part numbers for the power booster / master cylnder, please any help would be greatly appreciated. I'm useing 11'' granda roters with GM calipiers, and roters in the rear.
Thanks,
Mike

Double Venom · #2 (**permalink**) 01-01-2009, 10:32 AM

"Mainly Classics"......Havent heard that name for years! They too were really good until "Rutherford-CR1-" jumped on their band wagon. Tony couldn't fight him so he just went away.

Brakes have changed immensley since then, the biggest change is to an '87 corvette DISC master cylinder and the 7" booster. If your using GM Disc rear brakes-90% of the fading breaks can be blamed on the rear caliber pistons NOT being adjusted correctly if at all!
Most guys didn't even know they adjusted. Bleed forever and you can still end up with soft brakes. Pull your rear pads and look at the pistons...is there four small cut outs on the piston head? If it's what I think you have and I'm going way back here, these pistons screw in and out-be carefull if you push the pistons out it will take a special tool to get them to go back in.

The problem is the rear pistons aren't adjusted properly and there is too much clearance between the piston-pads and then the rotors. You use up most of your pedal just trying to get the rear pads to make contact and if they do it will be minimal pressure causing the fading.

Hope this has helped-MP Brakes, Wildwood, Baer all make great brake kits for the CR Cobra.
DV

62Cobra · #3 (**permalink**) 01-01-2009, 10:42 AM

You may try replacing the rubber brake lines to the front calipers as they can fail with age.

Pasta Power · #4 (**permalink**) 01-01-2009, 10:59 AM

Thanks DV, I will check that out....I'm useing stainless steel lines in the front. Yes I Re-purchased most of my remaining parts from Tony, at Mainly classics including my body.... Ed, I think I spoke with you a coulpe of years ago after I got screwed again by Jay K. at Classics by Ellite he really screwed my paint and body work up. This 18 year project has been nothing but a hair puller, but really enjoy driving it!!!

Pasta Power · #5 (**permalink**) 01-01-2009, 11:06 AM

Ed, I forgot to ask you if you know off hand what year Corvette Master cylnder / Power booster?
Thanks again for help.
Mike

Double Venom · #6 (**permalink**) 01-01-2009, 12:04 PM

Fella,
You have my sincere & deepest sympathies about "Kowalik" & can't help but take part of the blame since I sold him my business. Less than 30 days after he took over he started killing a businesss my family had taken over 30 years to build. The only thing good I can say is that he is gone! At least, I HOPE he wont / can't come back like so many of the crooks in this business.

Oh well-moving on, '87 Sir, booster and master- just make sure you ask for the 7" booster.

Actually-a little history you may not know, myself, Tommy from Bethania garage, and two other guys went into busines with Tony before Rutheford tried to get Tony's money so he went after Don.......

I often wonder if Tony could have pulled it off, he was one of the good guys!
DV

Pasta Power · #7 (**permalink**) 01-01-2009, 12:18 PM

Thanks Ed, Jay's lack of passion, and workmanship is certainly no reflection on you or your achivements....Thank you for staying plugged in with the weekend mechanics like myself. I have moved past all the bad luck I've had with this project, now I'm just trying to tweek it in. Ed, I'm not using disk brakes in the rear yet I have rear drums, should I still change to the Corvette Booster/Master?

Thanks,
From Pinckney, Michigan
Mike

Double Venom · #8 (**permalink**) 01-01-2009, 02:21 PM

No,
you will need a master for disc/drum and an appropriate proportionaing valve. Sorry I do not have those numbers anymore. Might check MP brakes site, they have tons of correct info there.
DV

JAC · #9 (**permalink**) 01-02-2009, 10:34 AM

They also moved the pivot point for the brake pedal in the pedal box to increase the ratio.

Double Venom · #10 (**permalink**) 01-02-2009, 12:23 PM

JAC,
That wont apply to Pasta Powers' kit. Unless he changed everything but the brake lines.
His kit has to be a very late '70's or early 80's.
DV
PS. The pedal was moved to make the "perfect" ratio of 6:1 with the new brake systems.

scales · #11 (**permalink**) 01-02-2009, 12:32 PM

Maybe a 10lb. Brake Residual Pressure Valve (RPV) installed in the rear Brake line ?

Marty.

Pasta Power · #12 (**permalink**) 01-02-2009, 01:50 PM

Thanks guys, I purchased my kit in 1991 and for various reasons it's taken me this long to work all the bugs out, but I do enjoy wipeing them off my windshield. I have read about moving the brake peddle back in past posts, I was not sure if that applied to me with the 1975 - 1979 Mustang II booster/Master.

Thanks again for your responses.
Mike

Double Venom · #13 (**permalink**) 01-02-2009, 06:46 PM

Ooops,
Got my decades wrong!-Add one

DV

David Kirkham · #14 (**permalink**) 01-02-2009, 06:51 PM

I don't know what you are working on, but I do know that the right brake pads make a tremendous difference on how a car stops!

David

Pasta Power · #15 (**permalink**) 01-03-2009, 08:40 AM

I'm working on a CRI frame I purchased in 1991 with their build manual that's about all I got from them, but they got all my money. The rest of the parts came from Mainly Classics. I finnaly got the car on the road 3 years ago, and the brakes are not right. I'm at a point where some major changes need to made. One question I have is was a change made with Master/Booster setup since 1991 in the new build manual?. I currently have the Mustang II 1973-1979 Master/Booster, I also have the 11" Granada roters with GM calipers, with rear drums, the engine is a 351W built to edlebrocks preformer RPM specs.

yesterday my father gave me a Wilwood Mustang II spindle assemblys with the Wilwood dynalite 4-piston calipers, and 10 3/4 rotors, from a project he gave up on some time ago, (I think he's tired my complaining). Before I bolt this assembly on will the current Master/Booster setup work?, or should change that out also, I have read about changeing the peddel location in past posts. From the input I have gotten from this post, and what I have read from past posts if I convert to disks in the rear I need to change the Master/Booster setup.

Last question; should I just bolt on the new spindle assembly, with the current Master/Booster and see how it works, or bite the bullit and convert the rears to disk also. (this option will take alot convincing to she who must be obeyed that spending more money on the car is good thing)

Thanks again guys, like many people I'm just a weekend mechanic who appriciates the input from this fourm.

Mike, from Pinckney Michigan

tcrist · #16 (**permalink**) 01-03-2009, 11:24 AM

Mike,
I would change it over to Wilwood disc's all around. I have the Wilwood disc's and master with the 7" boster. Also the Wilwood adjustable pressure valve on the rear brakes. Mine stops on a dime. My CR is also a late 80's/early 90's CR.
JMO, Terry

David Kirkham · #17 (**permalink**) 01-03-2009, 11:44 AM

Which Wilwood calipers are you looking for? We just might have some of the laying around here we would let go at a good price.

David

Pasta Power · #18 (**permalink**) 01-03-2009, 11:53 AM

Thanks guys, I have wilwood dynolite 4-piston 1.62 wilwood part # 120-4937-p for the front, I have no idea what I would need for the rear, and I'm assuming I would also need to replace my Master/Booster. If anyone has extra items they want to sell, please let me know.

Thanks again,
Mike

David Kirkham · #19 (**permalink**) 01-03-2009, 11:58 AM

We would need to know what size rotor you want to run in the rear. On our cars, we use Superlites in the front on a 12.2 x 1.25 rotor. In the rear we use the Dynalite calipers with a 12.2 x 0.81 rotor.

David

Pasta Power · #20 (**permalink**) 01-04-2009, 12:05 PM

Thanks David, but I think I'm just going to try the new wilwood rotor/caliper assembly my father gave me first, and see what that does. I also ordered a wilwood master cylnder, after reading tcrist's post. When I told my wife the rubber bushings in the upper and lower control arms were shot, and two ball joint rubber boots had tears in them, she's not going to let me upgrade my rears to disk this year.

Thanks again you guys, your input is very helpful.
Mike