Bizzare brake problem after turning right

[BeaterShark]

First, a little background:
Late last year, my brake pad caliper codder pin broke and I lost a brake pad. This ruined a rotor and caliper pistons on the driver's side front. I installed a new rotor and put in a o-ring caliper kit. This is when my problems began.

My brakes are pretty much fine as long as I drive straight or make left turns. I do admit that they are "softer" than I'd like, but there are no obvious problems. The brakes are not power assisted.

My problem comes in when I brake after I make a right turn. It makes no difference if I brake immediately after or 5 miles after I turn. Here is the best that I can describe in words what is happening. I lightly press the brake pedal and I feel resistance and the car will pull to the right. Then I increase the pressure on the pedal and the pedal gives a little and then the car tracks straight. I'm pretty sure that the "give" is the caliper pistons on the driver's front pushing the pads against the rotor, but this would mean that the pads are being forced away from the rotor.

I could understand this if it happened all of the time, but it ONLY happens after a right turn. It is 100% repeatable. My drive to work is about 12 miles and has 4 left turns and 4 right turns and the only times I had this problem is after the 4 right turns.

I have checked the bearings for play and it's within spec. I also have turned the wheel and checked that there is nothing out of the ordinary happening when the tires are turned. The brake line is fine and nothing appears to be intefering. Also, I cannot reproduce the problem when I'm not rolling.

I must also note that I did not bleed the rear brakes as I didn't touch them and the fluid level never changed in the master cylinder.

Anybody have any ideas?

 

[ScrantonScrambler]

replace your brake hoses

 

[vmrod]

Maybe the inner walls of the brake cylinders were damaged and the pistons are sticking a little. I don't know why it only messes up while you turn right though.

 

[BeaterShark]

Any particular theory behind changing the lines? Reall, I do appreciate the input, but I like to know why I'm doing things instead of just throwing money at the problem. I don't think it could be the lines and I didn't have the problem before the new rotor and caliper pistons.

The o-ring pistons fit in the cylinders *much* more snugly than the lip seal type. I'm sure the "give" in the pedal is from the pistons having a snug fit. I think the problem is that the pistons are either being pushed/pulled away from the rotor when I make a right hand turn. I'm really stumped as to what would cause it and was hoping maybe someone else had encountered this before.

Thanks for the input.

 

[ScrantonScrambler]

pull the pads & make sure that the pistons are not cocked in the bores.
you may have a bad or twisted rubber HOSE, not line.Be sure the hose is not kinking. Have a helper turn the wheel while you watch the hose. If you didnt change the rubber hoses when you did you brake job you really need to do that.

 

[72Mako]

Without being there stuff like this can be hard to diagnose. Obviously it's related to changing the LF caliper. I'll just throw some stuff out here to consider. A brake hose can look fine on the outside but especially if it is old, can be restricted/partially collapsed internally. When this happens, it acts like a check valve. I ran into this on an old truck. Is the hose being pinched when turning right? The LF caliper being the o-ring type and the RF being the lipseal type could be asking for problems. Aren't some o-ring calipers made sans the internal piston return spring? Just wondering if they should be replaced in pairs? Also I think it is advisable to bleed the entire brake system anytime the system is broken into. And it's advisable to flush the system regualarly anyway. I sure some other more experienced than I will chime in hopefully. Charles

 

[BeaterShark]

No, the brake hose is not kinking at all. I do plan on replacing it, and probably will this week, but I don't have much faith in it fixing my problem.

Yes, the o-ring pistons do not use the return springs. I ran with only the driver's rebuilt with o-ring for about 1 month. Then, this past weekend, I rebuilt the pas front with the o-ring kit.

The rest of the brake system was bled about 4 months ago. I will bleed the entire system again when I replace the hoses.

I guess it is possible that I have had this problem for a long time, but the piston springs would "correct" it before I could use the brakes

Time will tell.

 

[ScrantonScrambler]

if you are running an O ring caliper on one just one side that can also be your problem.
I was gonna just replace just one with the O Ring style when i had a front caliper go bad, asked the tech at VB if that would work. He said it would but not for long, that the O Ring vs. Lip seal calipers worked at different pressures................hey, that's what he said.
Always change the pads on both sides, even if working on just one caliper.
Let us know how you make out.

 

[Mac]

As a matter of safety, I've always replaced pads, rotors or calipers in pairs but I know not everyone is as fussy as I am. I wonder if your portioning valve might have dirt or ??? plugging one side but that wouldn't account for the right turn involved braking problem. Hmmm. Let's face it; there's a limited number of things which could cause this, especially on a non-power brake system, so you need to work your way through them systematically.

 

[resto75]

If you have o'ring pistons on one side only that is your problem. Put a o'ring caliper on the other side and it should go away.

 

[Vettehead Mikey]

I wonder if your portioning valve might have dirt or ??? plugging one side but that wouldn't account for the right turn involved braking problem.

Hi Mac.

'69s don't have proportioning valves.I believe they only started in '75 +-. My bet is on the flex hosing. Bet you a Kokanee!

BTW do you ever hear from Ron D?

 

[Mac]

Hi Mac.

'69s don't have proportioning valves.I believe they only started in '75 +-. My bet is on the flex hosing. Bet you a Kokanee!

BTW do you ever hear from Ron D?

Next time I'm in Montreal, you can collect!! :L

I exchanged greetings with Ron during the holidays. He says he's doing well but he's still bitter about Corvettes and Forums. While I can somewhat understand the former (because of his business failure) I don't get the latter. I hear he's severed contact with most everyone else but me, even the Vetteheads. Even our contact is only occasional and I'm the one who initiates.

 

[cwerve74]

Here is a different twist on your problem. This may be a strech but when you had the pad damage and had to replace the calipar there must have been some large forces at work. Could the brake mount on the spindle be damaged in such a way that a clockwise rotation causes movment but not in the counter clockwise direction. Something like a crack that needs a good twist to make it move. Something you might not be able to do just see staticly inspecting the brakes. I am sure you have been all over this set of parts but maybe using a big tool to put some torque on the calipar with a lot of light on the parts. Just a thought. I would not rule out the hose or the both need to be the same calipar idea, but I always like to go back to "what started the problem" and look when nothing else makes sence.

 

[BeaterShark]

The hoses will probably be replaced tonight and all brakes bled.

I did put o-ring in both front calipers this past weekend and ran with driver's only for about 1 month prior and there was NO difference. Also, these are not VB&P o-ring pistons, but some from Precision Engineering ( http://www.fixvetteparts.com/ ).

I know this is hard to describe and I'd probably not understand it if it wern't happening to me, but I'm sure somehow the fluid in the driver's front caliper is being pushed/pulled out of the caliper a little when I make a right turn. The only way I can this would happen is either from the rotor/pads forcing the pistons in a little, or from some suction inside the hydrolic system.

I'll post an update once I replace the hoses and bleed them all.

Thanks for all of the replies.

 

[BeaterShark]

Update - I replaced the hoses and bled the entire system last night and the problem still exists.

Any other ideas?

 

[Dwight]

It sound like you already have a lot of time invested in this problem, but would you consider swapping the front rotors - side to side? See if the problem follows the rotor. You are right - something is forcing fluid back to the resevoir. How are the slide pins? Possibly one bent so that a left turn puts rotor pressure on the stationary pad vs. right turn puts pressure on piston side pad? Maybe take the same right turn twice - once without and then with pedal pressure - see if that makes a diference.

 

[cwerve74]

I know you said the wheel beerings are OK. Are you 100% sure? Have you put a dial indicator on the rotor near the top and then applied some good force to the inside then the outside of the bottom of the rotor? What is the rotor run out on the left side? Could the runout be larger in a right turn? You would be looking for real small movments here so a dial indicator is required.

 

[vettenick]

I would take a close look at the right caliper. There could be corrosion inside causing the pistons not to fully retract, ultimately causing the right side brakes to kick in a little before the left side. It's normal for the rotor to push the pistons due to some play when turning. It could cause the piston/seal to catch on a ridge inside of the caliper and then creating your problem.

 

[dman]

left caliper sticking. r&r calipers and b done with it !!!!!!!!!!!!

 

[BeaterShark]

I think I found the problem. I replaced the bleder valve with a speed bleeder one and I have a firm pedal, even after right hand turns.