Front disc and pad replacement, now feels like tracking is out?

[kingofthehill]

Saab
9_3
2.8T V6
2006
113k

Good afternoon all.

I suppose there should be a straight forward answer here but despite being a reasonably competent DIYer (so says I ) I could use a little friendly advice please.

I changed the front break discs and pads this weekend. No problems cropped up that I know of; I carefully cleaned the pad guideways and and sliders and greased the sliders before reassembling everything. Straight forward enough.

However, I now have what feels like bad wheel alignment, the car drifts to the right when I let go of the steering wheel. This wasn't present before changing the brakes.

I have jacked the car up and checked that the wheels are turning freely. They both turn easily, albeit with slight resistance requiring a small amount of effort to turn them, and they both feel like they have the same amount of resistance.

The only thing I can think of is that the caliper bracket bolts were VERY tight, which led to me (working on the ground) beating a spanner with a lump hammer to undo them. It feels like I may have upset the alignment when driving the car but I'm unsure whether that is the case or there is an issue with brake drag or another problem with the brake install.

I suppose I'd like to rule out brake related problems before forking out for a wheel alignment but could use some guidance in this respect.

Any thoughts?

Thanks in advance!

 

[Burnerman]

I can’t see how the tracking could be disturbed by doing what you have done, and my initial diagnosis would be a slightly dragging caliper. However, give things a chance by doing a few miles with moderate braking just to let the pads bed in, and then checking the temperature of each wheel to see that they are about the same (dont touch the disc though )
Does the car pull only when braking, or all the time?
After that, check for wander once more and obviously check the tyre pressures.
When you removed the old pads was the wear even on them?
John

 

[Old Salt]

What are the tyre pressures?
Camber of the road you are testing on?
Does the car drift or snatch when braking?
Both calipers still free to move?

 

[kingofthehill]

I can’t see how the tracking could be disturbed by doing what you have done, and my initial diagnosis would be a slightly dragging caliper. However, give things a chance by doing a few miles with moderate braking just to let the pads bed in, and then checking the temperature of each wheel to see that they are about the same

I drove the car around locally. Built up area, slow speeds with breaking mostly at junctions. Drove it like this for about 30 minutes. Not really any change after that. Maybe I need to take it on an A road run with more severe breaking at the roundabouts to really see if that beds them in. The car is taxed but is essentially off the road and garaged permanently as it's up for sale. I won't really be using it if I can help it as I've spent an eon making it look nice and fixing all the broken bits.

Does the car pull only when braking, or all the time?

The car is fine when braking but drifts to the right when not on the brakes.

When you removed the old pads was the wear even on them?
John

I didn't spend much time looking at them but didn't notice anything bad that caught my attention.

Thanks for taking the time to reply.

 

[kingofthehill]

What are the tyre pressures?

34psi all around.

Camber of the road you are testing on?

The issue is consistent regardless of where I'm driving. I tested on lots of different streets while I was out.

Does the car drift or snatch when braking?

No. All in all the brakes feel perfect.

Both calipers still free to move?

No idea. Do you mean the pistons or the caliper on the sliders? I guess to inspect this and confirm proper function I will need to dismantle everything to test, right?

As per the previous respondent, thanks to you also for sparing the time to reply to me here.

 

[Burnerman]

For sure, if you intend to sell the car then this needs to be fixed.
Any drag on any brake will show up at MOT time and you can get the car tracked too.
The only thing I can come up with - if the old pads were very worn then the caliper piston is now in a different position and maybe some rust has tightened things up a bit, but that’s a bit of a long shot.
Certainly, using a hammer on the caliper bolts can’t upset the tracking.....unless you missed and belted the track rod
Good luck with it!
John

 

[Old Salt]

If it was all okay before I would revisit the brakes and make sure everything looks and feels ok.

Strip down and re-inspect if necessary to make sure you haven't missed anything.

Then check the rear brakes are adjusted correctly, tyre pressures ok.

Jack the front wheels up slightly and put a crowbar or lever under the wheel and lever gently up and down looking for any play.

Check the wheel bearings for play and the obvious bits at the front, ball joints, track rod ends etc.

If nothing shows up I would either mot it or have the tracking checked, both would cost about the same on one of these fancy computerised rigs. Having said that if it fails an mot I believe the history is now available online to any prospective buyer.

Good luck

 

[baldykev]

Did you take both front wheels of together ? you may have mixed wheels up . They may be directional rotation . swap them side to side and see what happens.

 

[kingofthehill]

Hi baldykev.

Yes I did take them both off. Actually, they have all been taken off and gone off for powder coating so they are probably not on the same corners as they were when they were taken off, tyres probably would have been on different wheels as well as these were removed for the powder coating. Hmmm....

I have never heard of directional wheels though so I assume you mean the tyres, right?

It's a simple suggestion but you could be onto something. I'll swap the wheels around later, side to side and front to back and see what happens.

I suppose if that doesn't shed any light I am going to have to strip them down and inspect the sliders pistons and bracket slideways again and make sure all is well per the above comments.

 

[baldykev]

yes tyres. if they are they will have an arrow on them to show direction or look at the tread pattern. Also some times when powder coated you have a build up around bolt/nut holes make sure that area is clean if not when tighten nuts/bolts the wheel does not sit correctly.

 

[kingofthehill]

Thanks, I'll check it out.

 

[Old Salt]

Did you take both front wheels of together ? you may have mixed wheels up . They may be directional rotation . swap them side to side and see what happens.

Good shout

 

[kingofthehill]

Evening all.

Just to close this out....... a buyer requested to view the vehicle at very short notice and was happy to take it as it was after a little negotiating. I hadn't had time to resolve the issue so unfortunately I'm unable to conclude this thread with a fault diagnosis.

Thanks to those of you who took the time to help.