joewill

turning the wheel by hand as a helper applies the brake will only tell you of a complete brake failure on one side. your muscles are just not strong enough.

take a cold car with cold brakes out and drive around the neighborhood, selectively applying your brakes on and off from different speeds. get the car home and check the heat of your rotors with your fingers. ( watch out may be very hot). your coolest rotor will be the one not clamping the same as the other. that is where your trouble is. check your rear rotors for heat also. one rotor may be heat glazed or a hose may not be passing fluid, or a caliper may be seized. or your pads are contaminated.

if the temperature is the same then you have a suspension issue with alignment while braking and your braking system is fine.

BlackC3vette

C3 4ME -
Turning a wheel by hand with a helper applying slight pedal pressure absolutely does check for complete failure, as in a frozen caliper or a totally collapsed hose. It's a very basic starting point.

Please don't press your fingers up against a hot rotor, borrow or buy a laser type thermometer. I bought a Raytek online, fairly inexpensive. I am sure H.F. has them.

Before checking rotor temps, I would do a basic bleeding on the right side to check for good fluid flow/pressure. When you crack open the bleeder, it should have some pressure to it until the helper pushes the pedal to the floor. If not, the hose could have some internal restriction.

C3 4ME

I do have a laser temp gun, and didn't think of that. I'll try that next. Thanks guys!

C3 4ME

I pulled the right front caliper this evening, and without doing anything other than removing it, a couple of drops of brake fluid appeared on the floor, so I think I've found the culprit. I be looking into rebuilding or replacing the caliper.

C3 4ME

Heeeelllllpppp, lol! Ok, as I said at the beginning, I've replaced both front brake hoses. I then decided to rebuild the RF brake caliper, which turned out to be a colossal failure. It leaked like a sieve all over the inside of wheel, and even sprayed brake fluid down the side of the car (fortunately DOT 5 so no paint damage). Tonight I put a NAPA remanufactured caliper on the right front. I still have a pull to the left. I'm pretty sure when I stomp the brakes only the left front locks up, not the right front. I'm trying to get the brakes sorted so I can drive 300 miles to a car show next weekend, for which we leave next Thursday morning. Also, I tried my laser temp gun, and saw a about 20 degrees cooler on the right front rotor than the left front after a couple minute low speed drive through the neighborhood.

'75

Have you tried swapping front rotors left to right and see if the problem follows?

C3 4ME

Didnt think of that. Might have to try that next, thanks!

BlackC3vette

You may still have some air in the system.

joewill

brake fluid on your right pads.. changing your coefficient of friction on one side .
make sure all is equal on both sides.. clean pads, rotor surface, no air in lines, bearings equal tightness,

plugged up distribution block under your master cylinder? crimped line?

do your heat test again..

DUB

That would have NOT help this problem.

Because.... assuming that the rotors are are above minimal thickness standards ( minimal thickness is 1.215")...and that the run-out is correct (very important)....and that the front wheel bearings are set correctly..also very important.

But simply swapping out rotors is not going to do anything. Because the previously mentioned inspections and set-ups that need to be checked would verify IF there were an issue with a badly warped rotor.

Swapping out rotors that have been checked is not like swapping out spark plug wires.

I agree and mentioned something much to that effect back in POST #6 (fourth paragraph).

I was under the understanding that the brake guild flow was good and not being restricted. I am still feeling that this is the problem is fluid flow.

OR...It just may require you to obtain a brake pressure gauge and measure the PSI of the system at each front wheel.

And this is also assuming that the steering components on the car are GOOD....and no worn out control arm bushings, etc. Becasue...fit the caliper is GOOD...but when it is applying pressure...the entire control arm assembly is moving....thus...changing how the car is tracking. Also INSPECT all weld on the lower control arm to make sure that are GOOD...because I have seen my fair share of the welds popping and thus...changes EVERYTHING when you hit the brakes....or make aggressive turns.

DUB

'75

Dub, you need to spend a little less time trying to discount others ideas. If you have advise for the op's problem, then by all means try to help, but the above comments from you just show me who you really are! You have been called out on this type of thing before by others, you seem to get off on trying to be the top dog all the time. Please don't bore us with another of your apologies, you are now on my ignore list!
I guess you've never seen a rotor that was glazed.

DUB

I am NOT apologizing for jack squat!...I have nothing to apologize for. I really do not give a hoot if I am on YOUR 'ignore list'....and IF you read the thread...I have been offering advice/suggestions.

Maybe think about what you suggest next time so people do not waste their time doing something that will not help....and THEN maybe I would not have to clarify WHY your idea has very little merit UNLESS tests have been performed. Simple as that....and if I 'spell it out' in a manner that offends you....that's all on you. I was not offensive towards you in my reply.

And if you can fell his frustration at this point in this process of finding problem...because I can......suggesting what you did was just giving him a false hope... UNLESS the other tests were preformed first.

Just trying to ..whats that...oh yeah....offer advice on the problem and SAVE the guy some time....and get it repaired at the same time.

IMAGINE THAT...someone getting OFFENDED in what I write.

BUT...'C34ME'...if you want to go ahead and swap the rotors and give feed back if the problems is now on the other side or the same side.

DUB

DUB

To C34ME and for those who may not know this...simply swapping rotors on your 1965-1982 Corvette can be easily done. BUT... what you may not know is that the rotor MUST be indexed...or it is WISE to do so. REGARDLESS of O-ring seals or lipped seals in the calipers. THUS...it takes shimming of the rotor to the hub to make it turn as true as possible. Which is why what I previously wrote HAS MERIT. I am not making it up.

SO...blindly swapping rotors or putting them back on and not knowing where they were located initially in regards to the wheel studs...can cause the rotor run out to be severe enough to cause for brake caliper issues.

DUB

C3 4ME

Thanks DUB. I think my next move is to re bleed the brakes on both sides on the front since both sides were open when replacing the brake lines. I will check the for broken welds too. I have confidence that the steering components are in good shape because I had the car looked at by a buddy who's done front end work for about 40 years.

C3 4ME

I think I'm going to take the car out for a longer drive tomorrow to let the brakes get good and warm and re check temps. I wonder if you're on to something about the pads too though. When the caliper I attempted to rebuild leaked like crazy, I'm sure the pads got brake fluid on them. I did clean them with brake cleaner last night before installing them in the new caliper though.

BLUE1972

Just a thought:

Dot 5 brake fluid is Silicone based.

Just in case I would clean the rotor with rubbing alcohol and brake cleaner. I would scuff the rotor with 400 paper.




Has anyone looked at the power steering setup. If the valve is sloppy or the cylinder is leaking internally it can cause problems.

If the trailing arms are sloppy that can cause rear steer.


I did see a mention of a temperature difference in the front rotors. If they are the same brand, and thickness then I would think about rotor or pad contamination.

I the old days (>50 years) we had an adjustable bar we put on the seat and brake pedal to apply some pressure on the brakes. We would then use a torque wrench and measure the torque on each side to turn the wheel. Usually gave the answer. Sometimes you could also find a suspension issue or component that was questionable.

Hope you find the issue.

DUB

Good point. If the control valve were not balanced....when he drives it....the car would head to one side or the other. This can be easily checked in a few minutes.

. But if he drives under 5 MPH...and taps the brakes and it pulls...to one side...then I feel it is a brake pressure/fluid issue.



VERY GOOD IDEA! That could take out the test of the actual brake fluid pressure at each caliper and save some time.

DUB

C3 4ME

The plot thickens! I re bled the brakes and drove the car further and there was no improvement. Drivers side rotor was at about 130 degrees, passenger at about 100. I realized I had a new set of pads so of course decided to install them. When I went to push the Pistons back in on the new caliper, the new caliper leaked. What I also found was an idiot move on my part. The rotor was completely covered in brake fluid from the original caliper leaking all over everything. I have now cleaned the rotor thoroughly, hit both sides with a scotch brite pad, and will install the 2nd replacement rotor tomorrow, along with the new pads on both sides of the front. Crossing my fingers that tomorrow when I get to work on it again, all will be OK.

DUB

DUB

C3 4ME

2nd new rotor installed and new pads. I think we can finally put this issue to bed! I'm planning on rolling out early Thursday morning for Myrtle beach to the Run to the Sun car show I've been going to for years. Thank you to all who lent their wisdom to my brakes drama, lol! I'm sending a virtual beer to you all!