new rotors, caliper kit & still pulls right when braking

[tbitz]

I have two new rotors, and today I just replaced the rubber "O" rings on both front calipers. The pistons in the calipers had a little surface rust which easily came off with a non-scratch rubbing pad. All four pistons were clean and smooth when I put them back together. The brake pads are not new. They have about 0.5" of usable material so I didn't replace them.

When putting the pads back on, I set it up so that all four pads are touching the rotor with the brake pedal release. This was accomplished by pressing the brake pedal with one pad removed at a time to get the right distance between the caliper piston and the rotor.

Took her for a test drive and when braking the car still pulls to the right. If I brake hard enough the front right wheel will lockup before the left wheel.

What else should I replace? Brake lines?

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Tony
'78 911SC

[island911]

perhap you have a control arm moviing in a direction it's not intended to.

---

'81 Platinum Metalic SC COUPE

[BRAINIAC]

Possibly brake hoses. My guess though is that your car needs corner-balancing.

Might also try swapping front tires from left to right to see if that changes things. Radial pull from a tire can sometimes only show up on braking.

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Tyson Schmidt
72 911 Cabriolet
92 C-2 Cabriolet

[BRAINIAC]

I just re-read your post. I think from your description it sounds more brake related than what I posted earlier.(Locking up the right front wheel and pulling right.) Try new brake hoses first.

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Tyson Schmidt
72 911 Cabriolet
92 C-2 Cabriolet

[MikeRJ]

Had the same problem two weeks ago (also changed a caliper). Took it to the wrench and he pressure bled the system from the top and test drove it. He said that a little air came up when he hooked the pressure bleeder up. He didn't even charge me (I do give him alot of business). Could be something as simple as that, I was expecting on of those three figure visits. The car stops like it should now!!!! Hope you get off as lucky as me.

[Early_S_Man]

Three questions:

1. If you were going to replace the rotors, why didn't you replace the pads?

2. If you were going into the hydraulics, why didn't you replace the rubber hoses? Any evidence that they [b]AREN'T 23 YEARS OLD???

3. Ever had a wheel alignment since you bought the car ... a real 4-wheel alignment?

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Warren Hall
1973 911S Targa
1992 Dodge Dakota 5.2 4X4 parts hauler

[rstoll]

Tyson, you wouldn't want to leave those tires swapped from left to right huh? Just a temporary trial???

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Robert Stoll
83 SC
83 944

[tbitz]

Answers to above questions:

1) I could try swapping the front wheels but they are unidirectional rotation so I don't think it is a good thing to do.

2) I had pressure bled all lines a few months ago when I replaced the rotor starting from the farthest wheel to the shortest wheel. I also bled the front wheels yesterday when I changed the seals in the calipers.

3) I didn't buy new pads because the old one's still have lot's of meat on them. I am trying to save money on maintenace wherever I can.

4) I did have a wheel alignment done last year, when I had the a wrench upgrade to "turbo tie rods". He said an aligment was done. This was just before winter and I had just bought the car. I put it away for winter and this summer when I drove her and got familiar with the car I noticed that it was pulling to the right (without braking). So much for the $65 alignment. I have decided that I would do everything myself. I spent a half a Saturday doing the alignment myself. I can describe how I did it if anyone cares to know. The car now tracks straight when not breaking.

Today I swapped break pads from left to right. There seems to be an improvement. The car still pulls a little but not as much. I was told to use some light sandpaper on the break pads to remove any glaze on them. I looked at the brake lines and they look OK. The rubber hose looks OK too. I think they were replaced at some time. They don't look dryed out or anything. I don't think they are 23 years old. I'll leave this as a last resort.

Question: The master cylinder has two fittings. One for the front one for the back breaks. Does it matter which one is used for front? Mine seems to be the reverse of what the Bentley manual shows.

Thanks for the help.



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Tony
'78 911SC

[Superman]

I think Tyson is suggesting the tire swap just as a temporary test. Swapping wheels changes symptoms, noises and such, very commonly. I'd try it temporarily, just to see.

I'd also continue to examine the hoses and hard lines. If they are switched at the MC, and you are sure they are switched, switch 'em back. If I could not see anything wrong, I'd probably bleed it some more times. It can be difficult to get all the air out of a system. Loosen the mounting bolts on the left caliper, and tap the caliper with a metal tool. Hard enough to get bubbles to break loose.

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'83 SC

[MikeRJ]

[QUOTE]Originally posted by tbitz:

2) I had pressure bled all lines a few months ago when I replaced the rotor starting from the farthest wheel to the shortest wheel. I also bled the front wheels yesterday when I changed the seals in the calipers.

TBITZ, I also replaced the seals in the calipers (front) and my car pulled to the right when braking. I also presure bled in the proper order as per manual. But, there was still air in the line or master cylinder someplace. I couldn't figure it out so I took it to the wrench. Like I said before he used one of those presure bleeders that screws on the reservoir and a little air came up when he presuized it, he topped off the fluid and everything worked fine, no more pulling to the right. Your problem "may" be as simple as that. It's at least worth a try.
Good luck.

[ppendle]

Same prob a couple of months ago...solved by swapping only the outboard pads side to side. has the car been doing this only since the pads were installed new?
pendleton

[BRAINIAC]

Rstoll, yes. I meant temporarily to eliminate tires from the equation. The only way to *permanently* swap them from side to side is to flip them on their rims and then swap sides. Can't do that if they are asymmetrical tread, but works for directionals.

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Tyson Schmidt
72 911 Cabriolet
92 C-2 Cabriolet

1. Any contamination on the pads will cause problems.
2. Deglazing or cleaning the brake pads with brake clean will not take care of a contaminated pad. Once you get them hot they will leach oils back to the surface.
3. Did you clean the corrosion inhibitor off the new rotors? Brake clean and soapy very hot water works.
4. Why the steps with the pad to rotor clearance?
5. If you suspect the brake lines are bad look for cracks soft squishy bumps wet spots.
6. I would also be interested in knowing if the pads are wearing evenly.
7. It sounds like your left front is not working as well as the right
8. Are the wheel bearings adjusted correctly
9. Is the tire pressure ok on all of the tires.
10. Was the rotor mounting surface on the hub clean and free of burrs? Did you torque the rotors to the hub?
11. If there is one area you want to have everything right it is with your brakes.
12. Your 2nd post says you have pad problems.
13. The above is not in any order.

Chris Sherwood
ASE Master School Bus Technician

[jlex]

Had the same problem with pulling to the right when braking on my '85 Carrera. Didn't think too much about it since it wasn't real severe. Did a normal maintenance thing this spring by using the pressure bleeder (Motive brand) and replacing the old fluid with ATE Blue... my "pulling" problem disappeared after that. Must have been a bit of air in the line, although I didn't see any expelled when bleeding. Just my experience.
regards,
jlex.

[ras911]

If you replaced the rotors I would certainly spring for the 25 dollars for the new pads. It's great to go fast , but even better to stop fast. IMO dont scrimp where safety or performance is involved. So New Pads and re-bleed . Good Luck!

[tbitz]

I have pressure bled my brakes. I have a homemade pressure bleeder. It is essestially a 2litre soda bottle with a silicon hose fixed on the cap. I use my compressure to pump up the bottle and I put the hose on the overflow nipple on the master cylinder resevoir. Works great. I used ATE blue break fluid. While bleeding I tapped the calipers to help any air bubbles go out. I don't think bleeding is my problem.

Now that I have swapped pads and driven the car with some hard breaking the pulling to the right is very little. Almost not worth trying to fix. But I will try some of the above suggestions (wheel rotation, etc..)

Still don't have my answer on which brake lines connect to which side of the master cylinder. Currently my front breaks are connected to the rear fitting. The rear breaks are connected to the front fitting. The bently manual has a schetch showing the opposite. Can someone check what they have.



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Tony
'78 911SC

[Jdub]

Bite the bullet and replace those brake lines. They ALWAYS look just fine from the outside.

I have performed three rotor/pad/frnt wheel bearing jobs. In two I replaced the brake lines as well: guess which job required me to go in and replace the brake lines that I hadn't from the start? You bet: pulled something awful, but the WORST part is that if you have a hanging piece within those lines, you will have 'pad rub, glazing, etc. that will NEVER stop, only get worse.

Trust me. Get a nifty set of stainless/Kevlar/rubber; whatever, and replace those lines unless you KNOW for sure they are less than 5~7 years old.

Jw

[TargaEuro]

The pads may have some life left but replacement is a must with new rotors. If you look at the old rotors and notice any imperfections, grooves, scores etc. chances are the friction surface of the pads are going to have grooves and imperfections on them aswell. Its is difficult to see imperfections on a pad and they may look fine but toss them and put some new ones on those 62 dollar rotors. Even when you have them resurfaced, replace the pads its just good practice....TargaEuro