signify

Just refilled master cylinder and braking has vehicle pulling to right hard . What is the best way to troubleshoot.

MelWff

Look at the left front caliper for a possible leak

doorgunner

I think pulling to the right means the right/passenger caliper is doing all the braking, while the left caliper or the rubber line connected to the caliper is faulty.

Double check the master cylinder for clear brake fluid/it should not be dark-colored or milky-colored...which would require the system to be flushed.

The easiest first repair would be to replace the rubber hose to the caliper with a new hose...
gently press the brake pedal to see if fluid comes out of the new hose...
keep the pedal depressed...
install the new caliper...
bleed the caliper and see if that solves the problem.

If the problem still is not solved.....see comments below;
Is there brake fluid leaking onto the tire or the ground on the left/driver caliper?
If so, you can remove the caliper and rebuild the seals...or you can buy a replacement caliper....bleed it and see if the problem is solved.

Expert forum members can give you better info.

Tampa Jerry

Which chamber of the master cylinder did you add fluid? If it was the rear chamber, that will give you an idea where the leak is located. If the caliper is leaking to the point of slippage, you will need to address the leak and replace the disc pads. If one caliper needs rebuilding, the others can't be too far behind. Have they ever been sleeved in stainless steel? When was the last time the rubber hoses at all four corners have been changed? Jerry

standswithabeer

jack up the left front wheel and see if the usual disc brake "drag" is present. if not, remove the wheel and check that the left, front caliper is free to move on the guides. if not, clean/polish the guides and pins. this can be done w/the caliper still attached to the hose, best to suspend it using a wire or something. how does the caliper bore look, if not clean or the piston is stuck i'd replace both front calipers. i replaced all 4 calipers on my '79 in 2013 w/AC Delco, zero issues in 10 years. price has moved up from $90ea to $140 or so now.

MelWff

C3 Corvettes do not use floating calipers. The pads are the only part that moves on the pins. There are no guides.

standswithabeer

ok, then make sure the pads are free to move on the pins.

67:72

Way out on a limb here, but did you happen to spill any of the brake fluid such that it could have gotten onto the driver front rotor or pads when you filled the master?

4-vettes

Or just air in the lines or one caliper. Inspect for leaks. You topped up the master. Where did it go? Did the master go empty?
if no leaks start with a complete 4 wheel flush and bleed.

signify

No leaks tire moves freely when turned,. opened bleeder screw fluid dribbled out . Both sides were checked this way Pads same thickness inner and outer. This all happen after i refilled both front and rear reservoirs after purgeing not emmptying them completely.

HeadsU.P.

Normally I would jump to conclusions that the left front brake is doing absolutely nothing.

But, what if the right front caliper is not releasing the rotor fully? A slight drag that's magnified when you apply the brake. Maybe the left front is braking just fine.

What would cause the R.F. not to release? Pistons / seals. Caliper bores.
Or, the brake hose. Sometimes they turn into one-way-check-valves.

You already said you have fluid at the L.F. bleeder. This time apply the brake pedal, release and immediately open the bleeder on the R.F.
If fluid shoots out of there, the hose is the problem. If it dribbles, look elsewhere.

signify

Just test drove vehicle after releasing both bleed screws to purge air, Car does not pull in either direction. I did see that both brake lines were replaced hoses also by me some time in the past. I surmise there was air in the passenger brake hose because of the bubbles I saw, but that hose could be breaking down inside. Thanks for every ones input
t

HeadsU.P.

Wow. You got off easy.
Don't forget, front rubber lines get a copper crush washer between hose fitting and caliper.. (not the rears)

signify

Thanks and looking for new replacements some from Napa it is not included

HeadsU.P.

At some stores the crush washers are included with front calipers. Not so with others.
And I see some vendors include two crush washers with a rubber hose "set" of four.

My local NAPA forgot the crush washer with my front caliper purchase. They had similar copper washers in cases but were not the soft metal that is needed.
Supposedly, these washers are a "One-Time" use only. But, I have reused them when I can't find replacements and no leaks.

Someone on this forum taught me the trick to attaching the hose to the front caliper. Install the hose on your workbench. Put the caliper in your bench vise and really torque down the hose using a line wrench. Then, install on the vehicle as one unit.