1975 brake calipers
Thread Starter
Racer
Joined: Mar 2012
Posts: 396
Likes: 13
From: New Bern NC
1975 brake calipers
I paln to pull my "new" baby out tomorrow and move her to my Father in laws garage to work on her. The previous owner said the front brakes leaked and he could never get them to stop. I havent seen them yet but this is what I know and I am looking for opinions here which I know at the moment is a shot in the dark.
he replaced:
1) both front calipers
2) both front flex lines
He bled them and the brakes worked fine but after a couple of days the fluid had leaked out. He also said he had done the work because the rear brakes had stopped working all together but didnt know how to "reset" the transfer block/proportional valve (I know this is going to start a fight as I have done a ton of reading on here about brakes but lets be civil, I really dont care what it does per say as long as I can get it fixed).
So my question is....
1) anyone have any ideas how to get the lines to seal to the calipers? He used new brass washers that came with it.
2) How do I reset the valve so I can pressure bleed the entire system and replace all the fluid with Dot 5?
Oh, he is an old school hot rodder/dirt track racer so he knows how to work on cars. The leaking drove him so mad he just stored the car and left it...hence the less then 7,000 miles.
he replaced:
1) both front calipers
2) both front flex lines
He bled them and the brakes worked fine but after a couple of days the fluid had leaked out. He also said he had done the work because the rear brakes had stopped working all together but didnt know how to "reset" the transfer block/proportional valve (I know this is going to start a fight as I have done a ton of reading on here about brakes but lets be civil, I really dont care what it does per say as long as I can get it fixed).
So my question is....
1) anyone have any ideas how to get the lines to seal to the calipers? He used new brass washers that came with it.
2) How do I reset the valve so I can pressure bleed the entire system and replace all the fluid with Dot 5?
Oh, he is an old school hot rodder/dirt track racer so he knows how to work on cars. The leaking drove him so mad he just stored the car and left it...hence the less then 7,000 miles.
Drifting
Joined: Mar 2011
Posts: 1,886
Likes: 9
When did the PO replace the brake components?
We all know the factory Corvette caliper is prone to leakage. Until I switched over to the stainless steel sleeved calipers, I never actually used up a set of brake pads. After a year or two, the cylinder bores in the cast iron calipers would rust, damage the fragile seals, and they would leak brake fluid all over a perfectly good set of pads, ruining them.
You need the stainless steel sleeved calipers. Many guys use Vette Brakes and Products; I bought mine from them 10(?) years ago. Stainless Steel Brake Company is another respected outfit. I am actually using the VB&P ones with Oring seals. I have no recent experience with VB&P- my calipers don't leak any more!
The other tricky part about a C3 Corvette brake is that the rotor runout and wheel bearing endplay absolutely have to be inside the spec. Anything more wobbly than that, and the calipers will suck air.
Other than that, it ain't rocket science, it's just a Chevy.
We all know the factory Corvette caliper is prone to leakage. Until I switched over to the stainless steel sleeved calipers, I never actually used up a set of brake pads. After a year or two, the cylinder bores in the cast iron calipers would rust, damage the fragile seals, and they would leak brake fluid all over a perfectly good set of pads, ruining them.
You need the stainless steel sleeved calipers. Many guys use Vette Brakes and Products; I bought mine from them 10(?) years ago. Stainless Steel Brake Company is another respected outfit. I am actually using the VB&P ones with Oring seals. I have no recent experience with VB&P- my calipers don't leak any more!
The other tricky part about a C3 Corvette brake is that the rotor runout and wheel bearing endplay absolutely have to be inside the spec. Anything more wobbly than that, and the calipers will suck air.
Other than that, it ain't rocket science, it's just a Chevy.
Le Mans Master
Joined: Feb 1999
Posts: 8,351
Likes: 75
From: Tampa Bay FL
Call (or email or order from internet site) Van Steel. They will set you up with a precision rebuilt set of calipers for either or both front and rear. I've not had a SINGLE problem with the calipers I bought from them. Quality rebuilt. And, if you have a need for full or partial rear trailing arm or rear bearing assembly rebuild, call them! You will NEVER have another problem with brakes (front or rear) or bearing assemblies (rear).
Van Steel... buy with confidence. 'nuf said.
NOTE: When I lived in Tampa, I first met the founders of Van Steel when they were still in the old 'site' (Rte 60?) before they moved to the location off of McMullen Booth Rd in Clearwater. They are a quality operation. I talked to both Artie and his son Danny on many occasions before I relocated to OH and now to AR. They live and breath corvette parts. Every time I visited, there was a ground-up corvete resto project in process on one of the available lifts.
Van Steel... buy with confidence. 'nuf said.
NOTE: When I lived in Tampa, I first met the founders of Van Steel when they were still in the old 'site' (Rte 60?) before they moved to the location off of McMullen Booth Rd in Clearwater. They are a quality operation. I talked to both Artie and his son Danny on many occasions before I relocated to OH and now to AR. They live and breath corvette parts. Every time I visited, there was a ground-up corvete resto project in process on one of the available lifts.
Last edited by TedH; Apr 4, 2012 at 07:03 PM.
Thread Starter
Racer
Joined: Mar 2012
Posts: 396
Likes: 13
From: New Bern NC
He did the work about 8 years ago. The leak is from the flex line connection into the caliper, not the caliper sleeves.
I am keeping all the original parts on anything I replace....or in this case the calipers wont matter as they are not stock. I will check the websites.
I am keeping all the original parts on anything I replace....or in this case the calipers wont matter as they are not stock. I will check the websites.
Race Director
Joined: Jul 2001
Posts: 15,892
Likes: 42
2) How do you know that the valve needs to be reset? Is the light on? If the front brakes fail, all the fluid pressure would go the back, so I'm confused why the backs don't work. Forget DOT 5 unless you're replacing 100% of the components.
Thread Starter
Racer
Joined: Mar 2012
Posts: 396
Likes: 13
From: New Bern NC
I am wondering if he didnt torque them all teh way to 22lbs... thats a small line to be placing that pressure on. He said you could see the fluid trail from it which bothers me since all the parts are new. Tomorrow I hope to get her moved and the front wheels off so I can poke at her.
As for the back brakes, he said they werent working at all and that another vette owner told him to reset the "switch". Not sure if the brake light is on or not but hope to find out tomorrow.
I was going to DOT 5 as I know it has the least compression and I plan to replace all the brake fluid since she sat for soo long. I figure by now its contaminated from the leaking area letting air and moisture in.
As for the back brakes, he said they werent working at all and that another vette owner told him to reset the "switch". Not sure if the brake light is on or not but hope to find out tomorrow.
I was going to DOT 5 as I know it has the least compression and I plan to replace all the brake fluid since she sat for soo long. I figure by now its contaminated from the leaking area letting air and moisture in.
Thread Starter
Racer
Joined: Mar 2012
Posts: 396
Likes: 13
From: New Bern NC
On a complete side note...what the heck is the "bird cage" I see referenced in a million posts?
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
Le Mans Master
Joined: Feb 1999
Posts: 8,351
Likes: 75
From: Tampa Bay FL
I never used a copper seal between brake line and my c3 calipers. Is that inherint with flex lines? I've had two C3's and no (line-to-caliper) seals except the rubber o-rings between the caliper halves.
Instructor
Joined: Jan 2012
Posts: 156
Likes: 0
From: Mount Sinai New York
Where did you purchase your new brake components? In the midst of my 80 build that I'm working on now, I sourced 4 remanned calipers locally,they were JUNK! The workmanship was so obviously sub par I just returned them. If that's the case, go with TedH's advice with Van Steel.
They have complete packages with everything you need. My car sat for 10 years, and I'm able to replace everything (master,calipers, lines and pads for just more than $500.00. Well worth it.
They have complete packages with everything you need. My car sat for 10 years, and I'm able to replace everything (master,calipers, lines and pads for just more than $500.00. Well worth it.
Le Mans Master
Joined: Feb 1999
Posts: 8,351
Likes: 75
From: Tampa Bay FL
Where did you purchase your new brake components? In the midst of my 80 build that I'm working on now, I sourced 4 remanned calipers locally,they were JUNK! The workmanship was so obviously sub par I just returned them. If that's the case, go with TedH's advice with Van Steel.
They have complete packages with everything you need. My car sat for 10 years, and I'm able to replace everything (master,calipers, lines and pads for just more than $500.00. Well worth it.
They have complete packages with everything you need. My car sat for 10 years, and I'm able to replace everything (master,calipers, lines and pads for just more than $500.00. Well worth it.
Now, when I bought a pair of reman'd '882' casting smog heads from Western Auto (before they became Advance Auto), I liked them. They had something like all-new 2.10 intake/1.60 exhaust valves and all new moving parts AND probably less than the stock 76cc chambers. Had I a crystal ball, I would never have upgraded to my DART iron eagle heads with 72cc chambers. Not enough improvement for my driving style.
NOTE: I still have that pair of '882's in the DART cardboard boxes (since 2002)...
Last edited by TedH; Apr 4, 2012 at 07:54 PM.
Thread Starter
Racer
Joined: Mar 2012
Posts: 396
Likes: 13
From: New Bern NC
I dont know where he bought them but its been 8 years. I will look them over when I get the wheels off.
Accourding to the Clymer Corvette 1970-1982 Shop manual, the front brake flex lines do use a sepeerate washer when installed into the calipers, but only the front.
The seccond owner gave me everything, the original window sticker, the shop manual, the 1974 advertising pamplet for the 75 Corvette.... a wealth of info and collectables.
Accourding to the Clymer Corvette 1970-1982 Shop manual, the front brake flex lines do use a sepeerate washer when installed into the calipers, but only the front.
The seccond owner gave me everything, the original window sticker, the shop manual, the 1974 advertising pamplet for the 75 Corvette.... a wealth of info and collectables.
Thread Starter
Racer
Joined: Mar 2012
Posts: 396
Likes: 13
From: New Bern NC
Not throwing in the towel before getting a chance to work on the leak but has anyone used this kit?
http://www.parts123.com/parts123/yb....Z5Z5Z50000050G
http://www.parts123.com/parts123/yb....Z5Z5Z50000050G
Drifting
Joined: Apr 2007
Posts: 1,970
Likes: 45
From: Cameron Park CA
Discussions about Dot 3 & Dot 4 brake fluid vs. Dot 5 is a lot like arguing religion, everybody has their own belief. But here goes.
Dot 5, silicone, brake fluid actually compresses under pressure. It also collects air bubbles more easily than the Dot 3/4. For those reasons modern cars with ABS do not use Dot 5 fluid. Because it has an affinity for air bubbles, it is harder to bleed in a C2/3, and we all know how hard it can be to bleed our brakes.
As long as you use a quality Dot 4 fluid, with a high wet boiling point temp. and change it when it darkens (means it has absorbed water) you will be just fine.
No need to flame me if you're a Dot 5 user, just reread my first paragraph.
Dot 5, silicone, brake fluid actually compresses under pressure. It also collects air bubbles more easily than the Dot 3/4. For those reasons modern cars with ABS do not use Dot 5 fluid. Because it has an affinity for air bubbles, it is harder to bleed in a C2/3, and we all know how hard it can be to bleed our brakes.
As long as you use a quality Dot 4 fluid, with a high wet boiling point temp. and change it when it darkens (means it has absorbed water) you will be just fine.
No need to flame me if you're a Dot 5 user, just reread my first paragraph.
Melting Slicks
Joined: Dec 2009
Posts: 3,232
Likes: 656
From: Thunder Bay
I had a similar problem with my '79 a couple of years ago after installing new calipers. One would not stop leaking at the hose fitting. Fortunately I had a buddy with me on the road trip who is more knowledgeable than me. I thought I had them torqued adequately. Long story short (too late I know), he put a wrench on them and put at least twice the torque on them that I did. Problem solved. He put a heck of a lot more torque on them than 22 ft lbs. More like 90! I wouldn't have had the stones to do what he did, especially 500 miles from home, but it worked. Take it for what its worth.
Thread Starter
Racer
Joined: Mar 2012
Posts: 396
Likes: 13
From: New Bern NC
Your not too late! I plan to work on her tomorrow and I havent bought anything other then the Motive Pressure Bleeder. I do plan to pick up a bunch of brake fluid and new brass washers for her....plus I think the parking brake is locked so I will need some rust buster and then I will try and salvage her. I am trying my best to stay stock...as in facotry installed in 1974 stock.
Instructor
Joined: Mar 2012
Posts: 183
Likes: 0
From: Centreville VA
I just went through the same thing. I bought the car and the front calipers were shot, replaced the front with SS, also replaced all the lines and master cylnder.
That lasted about 2 weeks, with a new fully functioning brake system the right rear caliper sprung a leak, so from expierence my replace all 4 with SS calipers and save yourself 2 or more trips to the parts store.
That lasted about 2 weeks, with a new fully functioning brake system the right rear caliper sprung a leak, so from expierence my replace all 4 with SS calipers and save yourself 2 or more trips to the parts store.
Thread Starter
Racer
Joined: Mar 2012
Posts: 396
Likes: 13
From: New Bern NC
I plan to upgrade later, right now I just want to get her 'stopping" so I can get her moved, fix a few little things and get her to the body shop for a new front and rear bumper cover. I will out of town for a week so it the perfect time to get the covers done....and my friend that owns the body shop will be happier if I am not in town while he is working on her. I have a bad habit of 'hovering" around when its my vehicle.
Thread Starter
Racer
Joined: Mar 2012
Posts: 396
Likes: 13
From: New Bern NC
Pulled her out today and started working on her. Right front caliper went easy, left caliper is clogged internally. I have fluid to the end of the flex line and then nothing. I did have to tighten up the flex line to caliper connector. I could turn them with a wrench with little effort.
I posted picts in general under "Picts of my project car"
I posted picts in general under "Picts of my project car"
Last edited by ATIS; Apr 5, 2012 at 05:02 PM.