Hey Guys…I am a bit lost on my 1969 brake/driving issue. It’s a 427 without power brakes. Got off expressway and braked to a stop at light and end of off ramp. No issue stopping but afterwards the car pulls hard left under all conditions. Replaced rear rubber hoses and no improvement. Went on to drivers side front and replaced hose and then put on a “new” rebuilt caliper. Drove perfectly for 2 blocks. Then on a 30 mph to zero stop the condition returned and does not go away under normal driving. Pedal travel seemed longer on the 30-0 brake event. What should i try next? Seems like proportioning valve is front rear and no explanation why front left right can result in left bias and no explanation why pressure in drives side brake stays on while driving?? Uggh…please any advice appreciated. Thanks, Jim

 

So, is this a new car to you, do you know what work has been done to it, brakes specifically, and when?

 

Did you try a full bleeding of all calipers? You may have a constricted line on the right side.

Did you happen to pull all of the pads to see if any are contaminated?

 

Probably best to start with the basics to rule out problems: Get the wheels off the ground and ensure the bearings are running free (no binding or noise?), each wheel rotates freely ....calipers are not hanging up or binding? Or like a bad bearing causing the rotor and caliper (pad) to rub? Ensure the pads all have their friction material on them (rarely, but it can happen where the adhesive can fail and the friction material can flake off making it metal-on-the-rotor).

Like someone pointed out above, after you ensure all hubs/rotors are rotating freely, yeah, it would be a good idea to bleed them ..see if there is any air inside. Corvette brakes have a tendency of sucking in air, particularly if the rotors have excessive run-out. The caliper piston seals are umbrella seals (unlike any other modern car) and can act like a jellyfish and pump in air if warped rotors are making the pistons go in/out real quick.

Have you had any brake work done lately? Letting the "pros" do brakework is often the cause of brake problems on C3's. B/c the brake system is unique and needs special care.

 

I had to read all the symptoms three times but I think I got it.

Pulls hard to the left = right side is doing nothing.

Replaced rear rubber hoses. But not front?

Later, replaced left front hose. But not right front.

Again, left front gets some repair, new caliper. But not the right.

Because it's been pulling left, you think the issue lies there.
Me thinks you are looking at the wrong corner for the guilty party.
(rt front hose?)

 

This doesn't really apply to this thread (at least I don't think it does) but when a car pulls it could also be that the tire on the pulling side is significantly lower than the opposite side.

 

That's a good point...look for a broken belt/cord or unevenness on the tire surfaces. Air pressure differences. Damaged/worn suspension parts...etc

 

I know what you are getting at, smaller diameter tire.

But when a spare donut is put on the front it has no effect on braking.

 

Also...less air pressure or a tire flaw means more rolling resistance.

It's time to get it off the ground and look at all the components one at a time ....that's what I would do.

 

I have had the car since 2020. No work done on it until now…..

 

I bled both rears when I was working back there. Then just did the front drivers side since i focused my attention there after replacing the rear hoses did not do anything. Btw, hoses looked pretty fresh all around so the guy before me must have taken care of his baby. I don’t understand how a right side constriction can lead to a left side pull at all times and not just when pushing on the brakes. The car drives like the left side wheel or wheels are turning slower than the right side and thus the car wants to pivot around the slower turning wheels….At least that is how I am thinking about it. Also, after I replaced the front caliper and rubber hose, the car drove perfectly for a few stops. After this it seemed to get “stuck” on the left again and I am back to the steer right constantly to cointeract the left side pull. Thanks for all the replies btw. Especially the wheel bearing argument which i find intriguing….I don’t hear any noise from the bearings while driving but I will try rotating the two fronts to see if there is a difference in drag on left and right side. It seems to me that the assembly rotated freely after installing the drivers front rebuilt caliper but……

 

A couple thoughts to ponder over:

A rubber brake hose will seldom indicate any failure on the outside unless it's a crack or direct hit from an object.
They can look "like new" but it's the internals that can fail, invisibly. Over time, those hoses can turn into one-way-check valves, allowing fluid to pass one direction only.
Such as not pressurizing the caliper. Or not releasing pressure from a caliper.

The rear brakes do not really steer the vehicle regardless if the brakes are dragging or not. If one rear was completely locked-up, the car would still travel in a straight line.

Your pull-to-the-left is unequal brakes in the front. The calipers are trying to steer the car regardless if the pedal is applied.
You have done nothing to the right front brake, while the left front gets all the attention.

The distance between the brake pads and the brake rotor is so small that just the littlest, unusual change will affect the drivability (pulling).

With front up on ramps, hit the Right Front Caliper bleeder with a shot or two of PB Blaster. Loosen & close the bleeder several times.
With the bleeder closed, pump the pedal several times. Then immediately open that bleeder.
If the fluid squirts across the floor, you have an issue. (hose)
If the fluid dribbles out, its fine.
If nothing comes out, there is the problem. (blockage)

 

Thanks again for the replies. Big news…..took it around the block and did a couple of hard braking. It seemed like pumping brakes before the stop and i could lock the brakes during the stop. If i did not pre pump the brakes, i could not lock up the fronts. I was thinking about the comments about getting the brakes bled properly….and then it happened…braked hard to a stop and something let loose and it went from pull to the left while driving to a really hard, hard pull to the left. Limped it a block back home and up on the jack….front wheel was caved in a top and out at bottom. Lower ball joint showing and upper an arm mounts on driver’s side are messed up. Bushing on right side of drivers side upper mount almost fully out of the arm and left side is out…..Anyone have advice on replacing resetting the top an arm? Seems like spring/shock need to be removed and then an arm bushings can be replaced?

 

Huh. Here we were fixated on the brakes!
I sure could use a couple pictures of what's going on. Did a ball joint fail or did the A-arm come loose on the shaft, or both?

Taking out the spring and shock are the next steps. Make sure you read up on spring removal as it can be dangerous if you don't understand and follow the precautions. Once the spring is out, the spindle can be removed from the ball joints and then evaluating any damage and fixes from that point.

 

Also check the lower A arm mounting bracket to make sure it's not bent just for a piece a mind.

 

Time for a full front suspension rebuild. If ball joints are popping out then yeah......