Uneven brake pressure front and back.

goldxc70 · Post by **goldxc70** » 26 May 2022, 16:34

When I was switching my winter tires, I noticed the wear on the rear discs was very uneven as if they're not getting full brake pressure. The fronts were fine. Quickly checked for leaks (none), brake fluid level (OK), brake boost (OK although switch needs to be replaced)). Guess my next steps are VIDA and/or bleeding. I suspect it's got to be something around the ABS module pump.

Anyone have this experience?

Post by **vtl** » 26 May 2022, 19:15

Maybe you'll need to rebuild/replace the calipers as well.

In VIDA you can trigger ABS inlet/exhaust valves while bleeding the brakes with brake vacuum pump, it will let escape the air trapped in ABS. Also check the slider pins, the bracket, etc.

Post by **cn90** » 26 May 2022, 23:30

If you bleed the brake, search for my thread on ATE bleeder screws that you can buy for $4-$5.
You are in Toronto, chances are the bleeder screws are seized.
Soak them in PB Blaster for one week, then use some heat (info in forum).
Then new ATE bleeder screws.

Post by **chrism** » 27 May 2022, 08:06

Are the two pads within a given caliper worn unevenly? If so that would sound like a problem with guide pins or stuck piston(s).
If the pads are worn evenly within a given caliper but unevenly when comparing one caliper to another caliper then that may be a problem upstream like a collapsed rubber hose (or maybe a caliper pin/piston issue).

Post by **cn90** » 27 May 2022, 08:51

1+,

Brake rubber hoses, usually the front ones, are bad at >100K miles...

goldxc70 · Post by **goldxc70** » 28 May 2022, 20:13

Thanks for the replies. Last time I changed the rear pads, I cleaned and lubed the pins and checked for smoothness. I also bled the brakes all round some time back so was pretty happy that any air was out of the lines.

Did a VIDA check and got these brake related codes:

BCM-0103 Pedal position sensor faulty signal
BCM-0065 Stop (brake) lamp switch Signal outside its permitted range
ECM-9400 Brake pedal sensor - signal too high

Next step is to bleed the brake lines and check for evenness of pad wear etc.

goldxc70 · Post by **goldxc70** » 09 Jun 2022, 17:58

Update:
Lifted rear of car so I could look at both sides easily. Pads are wearing evenly on each wheel and on both sides. Did a complete bleed all round and found no obvious problems. Took it out for a drive later and in an empty parking lot, stomped on the brakes at 40kph/25mph and car stopped quickly without excessive nose diving. So everything seems to be in good working order. Will check again in a few days. Here are images of the rear rotors that concern me.

: Left Rear.jpg (182.82 KiB) Viewed 674 times

: Right Rear.jpg (205.22 KiB) Viewed 674 times

Herb Goltz · Post by **Herb Goltz** » 10 Jun 2022, 07:55

Man, those are some rusty rotors (even by Ontario standards!)! Very poor pad to rotor contact. Having a similar issue with my 2006, just bought pads and rotors. I have been buying pads and rotors from Max Advanced Brakes in Markham-- less than $100 taxes in and delivered. Make sure you lube up the caliper pins.

Post by **br0dy519** » 10 Jun 2022, 09:27

Work your caliper piston back and forth. It should go in easy enough with one hand on channel lock pliers. That was my issue with my overheating brakes. This looks very different though. I would probably get the rotors turned at that point and try new pads.

I got my last set of brakes from AutoShack. Mixed reviews but I can't complain for about $150 shipped front and rear pads+rotors.

Post by **cn90** » 10 Jun 2022, 09:42

Time to overhaul parking brake, new shoes, rotors, pads. Check if FCPEURO ships to Canada...

I wrote the DIY Parking Brake in this forum...