Car pulls right, even worse when braking

**jmile46** · 10-22-2018, 12:48 PM

Hey all, so my e34 has been having an issue where it pulls to the right when driving, i have to hold wheel to the left for it to go straight. And if i put wheel straight it pulls right very hard. When I brake this is amplified even more. I just installed brand new tie rods, steering drag link, and idler arm and car feels more solid but still pulls same way. I know I need an alignment but even after adjusting tie rods by eye(lol) I find it hard to believe car will pull in the same manner as before. What I’m trying to figure out is if its simply my thrust arms are shot or if I have a sticking caliper. Any thoughts guys?

Also if I get an alignment before replacing thrust arms, will I have to get another one after?

**moroza** · 10-22-2018, 02:52 PM

Originally Posted by jmile46

Also if I get an alignment before replacing thrust arms, will I have to get another one after?

EDIT: the textbook answer is yes. The real-world answer is that if you're replacing quality parts with same, and they are worn to the point of causing a shimmy (the usual reason for replacement) but not actually loose or deformed, you can *typically* get away with not resetting the toe afterwards. YMMV.

Lift up the front, check wheels for dragging, and swap them side to side (if they're directional, then swap them back after a testdrive).

**jmile46** · 10-22-2018, 04:41 PM

Originally Posted by moroza

Yes.

Lift up the front, check wheels for dragging, and swap them side to side (if they're directional, then swap them back after a testdrive).

By swapping them side to side, thats to identify if its a wheel issue causing this?

**Neel** · 10-22-2018, 05:11 PM

You've eliminated the possibility of it being a stuck brake caliper or stuck brake pads on the right side correct ?

**demetk** · 10-22-2018, 11:01 PM

String alignment is free and accurate.

**jmile46** · 10-22-2018, 11:05 PM

Originally Posted by Neel

You've eliminated the possibility of it being a stuck brake caliper or stuck brake pads on the right side correct ?

I have not. How do I do this? Just lift front and spin wheels by hand?

**mrgraybeard** · 10-23-2018, 10:02 AM

You could drive the car around the block and see if one wheel is getting warmer than the others.

**ross1** · 10-23-2018, 10:30 AM

worn control arm bushings can cause this

**jmile46** · 10-23-2018, 01:23 PM

Thanks for the input guys. Ill do some testing for a sticky brake, but either way at 252k shes overdue for some love. Just ordered new thrust arms, pitman arms, subframe mounts and diff mounts. All steering components are new. Lower control arms looks fine as do sway bar bushings. So this weekend Ill give ole girl a refresh, hit the road and see how it feels. Then alignment next week.

**moroza** · 10-23-2018, 03:13 PM

Originally Posted by jmile46

By swapping them side to side, thats to identify if its a wheel issue causing this?

Yes. But first...

Originally Posted by jmile46

I have not. How do I do this? Just lift front and spin wheels by hand?

...do exactly that.

Originally Posted by demetk

String alignment is free and accurate.

And determines only toe, which doesn't cause pulling.

**alang1990** · 10-23-2018, 08:56 PM

This thread should be helpful to you :

https://www.bimmerforums.com/forum/s...Push-Out-Right

… but you will likely have to rebuild your right calliper entirely. This op had an obscure problem and the solution was equally obscure, but did not require rebuilding, which is usually not the case.

**jmile46** · 10-23-2018, 09:04 PM

Originally Posted by alang1990

This thread should be helpful to you :

https://www.bimmerforums.com/forum/s...Push-Out-Right

… but you will likely have to rebuild your right calliper entirely. This op had an obscure problem and the solution was equally obscure, but did not require rebuilding, which is usually not the case.

If none of these other things help me, thats the path!

**jmile46** · 10-30-2018, 09:20 PM

Well, i finally had time to actually lift up the car today and upon spinning front wheels un the air, or should I say attempt to spin them! Looks like my right caliper is totally sticking. Can hardly even rotate the damn wheel by hand left side is not nearly as bad, but still doesn’t seem perfect considering a brand new wheel bearing. So looks like both calipers are in need of changing.

So what are my best options?
Buy new calipers or rebuild?
Also considering the right pads have been constantly rubbing will I need to change pads and rotors? Besides this issue both have plenty life.

**trackerrrr** · 10-30-2018, 10:16 PM

Originally Posted by jmile46

Well, i finally had time to actually lift up the car today and upon spinning front wheels un the air, or should I say attempt to spin them! Looks like my right caliper is totally sticking. Can hardly even rotate the damn wheel by hand left side is not nearly as bad, but still doesn’t seem perfect considering a brand new wheel bearing. So looks like both calipers are in need of changing.

So what are my best options?
Buy new calipers or rebuild?
Also considering the right pads have been constantly rubbing will I need to change pads and rotors? Besides this issue both have plenty life.

Before you go buying calipers, take the right one off, check the slide pins for corrosion and grease as necessary, and push the piston back in until it seats. Your piston might just be sticking along with the guide pins. When's the last time you changed your brake fluid also? Old nasty fluid is not conducive to a well functioning brake system.

**jmile46** · 10-30-2018, 10:20 PM

Originally Posted by trackerrrr

Before you go buying calipers, take the right one off, check the slide pins for corrosion and grease as necessary, and push the piston back in until it seats. Your piston might just be sticking along with the guide pins. When's the last time you changed your brake fluid also? Old nasty fluid is not conducive to a well functioning brake system.

Ahh good idea! Next time I get the chance, Ill definitely check that before spending ghe cash! But ive owned car for just about a year so brake fluid is unknown. Id imagine its old.

**trackerrrr** · 10-30-2018, 10:26 PM

Rebuilt calipers are not that expensive if you go that route. Just remember the brakes are the most important system on your car, get as good stuff as you can.

**moroza** · 10-30-2018, 10:35 PM

I've had a ~50% success rate rebuilding hydraulic cylinders at home. If you have lots more time than money, and can afford downtime, buy a rebuild kit and try your luck. Otherwise get good used (I have a pair assuming it's not a 540i or M5) or a quality reman, t.i not Cardone.

There's going to be a little brake drag even with healthy calipers. If you can get at least one or two full free-spinning rotations, I'd leave that side alone.

If there's no shimmy while braking and the rotors don't have grooves, big lips, or other damage, leave them and the pads alone too.

Originally Posted by trackerrrr

the brakes are the second most important system on your car after steering

FTFY

**jmile46** · 10-30-2018, 10:42 PM

Originally Posted by moroza

I've had a ~50% success rate rebuilding hydraulic cylinders at home. If you have lots more time than money, and can afford downtime, buy a rebuild kit and try your luck. Otherwise get good used (I have a pair assuming it's not a 540i or M5) or a quality reman, t.i not Cardone.

There's going to be a little brake drag even with healthy calipers. If you can get at least one or two full free-spinning rotations, I'd leave that side alone.

If there's no shimmy while braking and the rotors don't have grooves, big lips, or other damage, leave them and the pads alone too.

FTFY

Its a 525i. After looking into it id probably prefer to just spend the money on rebuilt. Drivers side definitely gets a couple rotations so it is probably fine. I do get brake shimmy when braking from higher speeds unfortunately. No noticeable flaws in rotors, possibly warped? Id prefer to leave all else alone. Is there a sure way to tell if the rotors are warped?

**jmile46** · 10-30-2018, 10:43 PM

Originally Posted by trackerrrr

Rebuilt calipers are not that expensive if you go that route. Just remember the brakes are the most important system on your car, get as good stuff as you can.

Whats a good brand of rebuilt calipers? I see some on ecs tuning.

**moroza** · 10-30-2018, 10:48 PM

Originally Posted by jmile46

Is there a sure way to tell if the rotors are warped?

Measure runout with a dial indicator:

Which will cost at least as much as the ~$30 for having both front rotors machined at just about any auto parts store.

**jmile46** · 10-30-2018, 10:53 PM

Originally Posted by moroza

Measure runout with a dial indicator:

Which will cost at least as much as the ~$30 for having both front rotors machined at just about any auto parts store.

Yeah I think I’ll just get them cut lol

**jmile46** · 10-31-2018, 10:25 PM

I took off the caliper today and checked my slide pins, nothing abnormal. I relubed them and compressed the piston and put everything back on. Spun wheel and it spun freely! But after first drive, no surprise same issue, and i spun the wheel and it was seized again. So it appears to me that the caliper won’t disengage after engaging, so does this mean Im looking at needing a new caliper?

**alang1990** · 11-01-2018, 12:01 AM

You probably need new caliper seals. The old ones have lost their flexibility and not allowing the pistons to move freely when brake pressure is withdrawn.

Since you already know how to take out and reinstall the calipers, why don't you rebuilt them yourself ? Unless you get a pair of rebuilt callipers cheap.

It is really unusual for caliper pistons to be damaged. But if you suspect yours actually are, or don't want to take the risk, then get rebuilt callipers.

**alang1990** · 11-01-2018, 12:10 AM

Actually OP, I have a hunch. Want to give it a try ? Open the bleeder nipple for the offending calliper and squeeze the piston. Brake fluid will come out, and possibly solidified dirt right behind the piston. Solidified dirt near the brake line may also venture out - perhaps that's whats causing the problem.

A bit of a long shot but hey. Anyway, that is the correct way to bleed brakes - the callipers need to be depressed a few times to get the mud out.

Make sure you are topping up the reservoir constantly when you do this do not let air get sucked into the reservoir.

**jmile46** · 11-01-2018, 12:13 AM

Originally Posted by alang1990

You probably need new caliper seals. The old ones have lost their flexibility and not allowing the pistons to move freely when brake pressure is withdrawn.

Since you already know how to take out and reinstall the calipers, why don't you rebuilt them yourself ? Unless you get a pair of rebuilt callipers cheap.

It is really unusual for caliper pistons to be damaged. But if you suspect yours actually are, or don't want to take the risk, then get rebuilt callipers.

I dont suspect the piston is damaged. I have no idea if it is or not. Im not sure what goes into replacing the caliper seals. Is there a diy? Id possibly give it a shot but if its super involved or tedious Id probably rather just bite the bullet on a rebuilt one for $90 on ecs. Would i need to do both sides? Or can I just fix or replace the one giving me issues? Same for pads and rotors? If I fix caliper, can I just cut rotors and leave pads?