Wife’s ‘08 Tahoe dives to the left when braking. Awhile back I replaced the right front caliper and bled the front brakes, no air, or so it seemed. The diving to the left has gotten worse since over time. IIRC I read you have to put the ABS module in a “bleed” mode or something like that using a scan tool. Or is it possible it may be a hose that is degraded inside????
Mark Ive' bleed early and mid 2000's with out scan tool.I do have a snap on scanner never needed for brake bleeding.Everyone has has there own technique for bleeding pumping multiple times IMO is the absolute worst way to bleed.When I install calilpers I just open bleeder and let it gravity bleed air is only in caliper.Pumping multiple times would mover air futher up into the system.Like you said the hose could be going bad.People and shops will put all new brake lines on and leave the old rubber lines on.Hydraulic lines don't last forever inspite of what people think.On a side note oil filters only have a shelf life of about 2yrs if they are not sealed in plastic. air &moisture start to break down the paper media inside.I always laugh when guys buy or looking for nos oil filters. Chris
There is a bleed function on the scan tool, but I rarely use it. If a scan tool is not available and the pedal is low, bleed the brakes as you normally would. Find a gravel parking lot and stop fast enough to activate the ABS several times. Most times that will bring the pedal up as long as there is no air in the rest of the system. I would never just replace one front caliper. Having one new caliper and one old can cause a pull. Both calipers need to slide the same. Chances are that the old caliper pins and bushings will be much tighter than the new one, although many of the rebuilt calipers that I've installed had absolutely no lubrication on the pins and bushings. Also, the new caliper piston will probably be easier to push in than the old one. It could be a faulty hose. Did you pinch it off while replacing the caliper? Were the calipers left hanging by the hoses, either this time or maybe on the last brake job or during a wheel bearing replacement? I've also seen grease from a leaking or overfilled ball joint on the inside of the rotor cause a pull.
Didn’t pinch line, I’ve never done that, don’t like the idea I just try to have everything ready when I disconnect the line and reconnect, whatever drips out drips out as long as the master doesn’t go dry there’s no harm. I think I’ll replace both front soft lines. It does have 256000 miles
Lol yep time is not friendly to ANYTHING This issue has gotten progressively worse, so I’m leaning more towards the soft lines verses air
Was working on a 1999 Chevy Baby Blazer that had brake "issues:. turns out the flex hose from the hard line to the caliper had rusted solid internally, keeping the rear right brakes on at all times, and made the ABS unit kick codes all the time, So, yeah. really check and replace those flex hoses!
Internal rust in the braking system is almost impossible. It’s a closed system that shouldn’t have any air in it to cause rust. What we have seen in sticking calipers is sometimes not a faulty caliper. It’s the hose torn internally creating a one way “check valve”, or flap, causing the caliper to either not release right away or apply, mostly not releasing… depending which way it had torn inside. Mostly causing it to not release though. You can’t see anything wrong with the hose externally. It will look fine from the outside. Chrysler’s are notorious for this, sometimes Fords, but hardly ever see GM products doing this. Actually maybe never have seen this problem with GM. We’ll sell a caliper first because that’s what the customer asks for. They’ll come back with the caliper we sold them stating it’s defective. That’s when it raises the red flag, so to speak. Sell them a hose and problem solved. They most likely never needed the caliper. In all my years we’ve never seen this problem with a rear hose. Which makes sense as the rear hose is stationary.
If I had a nickel for every ‘this caliper’s defective! It does the same thing the old one did!’, that was fixed by a hose, I’d have a bunch of nickels. (I’d try to sell hoses with or instead of calipers, but some folks like learning the hard way.) Patrick
