Potential ABS reverse problem on 2000 S70 SE

SL1M · Post by **SL1M** » 19 Sep 2022, 18:19

Recently I've had a problem in my 2000 S70 SE when in reverse. Whenever I tap my brakes my front left tire will completely lock up unless I get up to about 2600 RPM or shift into drive and roll forward a bit. It only seems to happen when I am moving backwards (in neutral or reverse) and I hit the brake even the slightest bit. I have taken out the ABS fuse, checked both of the modules on either side of the front wheels and I'm still not sure on what the problem is, has anyone ever dealt with this problem or have any ideas on how to fix it? Thanks.

Post by **foggydogg** » 19 Sep 2022, 21:02

I would be inclined to look at a mechanical issue first, especially since you already took the ABS put of the equation. In times when I back up in a hurry and jump on the pedal, it always slides the tires, so I always figure ABS hasn't got astern DNA.
Maybe check for loose fasteners, or a sloppy pad getting cocked in the caliper ?

Post by **MoVolvos** » 19 Sep 2022, 22:33

SL1M wrote: ↑19 Sep 2022, 18:19 Recently I've had a problem in my 2000 S70 SE when in reverse. Whenever I tap my brakes my front left tire will completely lock up unless I get up to about 2600 RPM or shift into drive and roll forward a bit. It only seems to happen when I am moving backwards (in neutral or reverse) and I hit the brake even the slightest bit. I have taken out the ABS fuse, checked both of the modules on either side of the front wheels and I'm still not sure on what the problem is, has anyone ever dealt with this problem or have any ideas on how to fix it? Thanks.

.
Sounds like caliper. Bleed and check color or potential rust. Time permitting remove the caliper and disassemble. Cylinder could have uneven corrosion due to moisture getting through the boots.
.

SL1M · Post by **SL1M** » 20 Sep 2022, 15:40

Took off wheel today, I think it is a bad inside pad, or at least a bad pad retaining clip. I think it slips out when reversing. I installed completely new brake system for the front tires about a month ago,(pads, calipers and rotors)I bet that when installing I must have bent one of the retaining clips that keeps the inner pads together. I took out the inner pad today and made the clips wider, I was able to reverse and brake multiple times before it locked up again. I’m 90% sure I heard the clip ping out of place when my brake locked up. I think all I need is a new inner pad, I’ll keep the suggestions in mind if that doesn’t fix it. Thank you for the replies.

SL1M · Post by **SL1M** » 21 Sep 2022, 20:14

Looked at the inside pad and saw this, since one part of the clip was missing I think it would get stuck in reverse.

: 411DA5DC-2757-4FEE-A46B-63007E668ECB.jpeg (444.07 KiB) Viewed 257 times

I took off the other clips so that it would work. Even after taking all the other clips out, the problem still occurs. I have next to brand new rotors, pads and calipers. I’m planning to just take out the pad tomorrow to see if it will still happen, then I will investigate the caliper.

Post by **scot850** » 21 Sep 2022, 23:09

Those clips are there for a very good reason to stop the pad floating. Those springs are to keep it in place flush with the caliper piston. You have to be careful installing those springs. I have never seen one break off before. If you swap that pad to the other side does the wheel lock up over there instead?

Neil.