Front bakes grabbing, grinding, and chirping after suspension refresh

rwmorrisonjr said:

Not yet since I didn’t crack the system when I did the other front end work. Will do that next if the road test sucks. Fluid is about two years old and still looks good.

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I agree, it's a long shot that you actually need a bleed. It's just one of the things I thought to try, especially since you had extra fluid in the reservoir. IMO, removing the extra fluid from the top should have zero impact on the skid steer affect. Please let me know if I'm wrong about that.

My concern would be the calipers. I always rebuild or replace them any time I do a brake job, as they often partially seize after the piston position is changed due to new pads. When I worked as an NIASE mechanic, it was considered standard procedure. The brakes may work, but the pads do not fully release the rotor, causing extreme wear and heat.

OP: How many miles on your Expy?

purevw (NIASE mechanic) - that seems overly cautious and would add a lot more expense & work to a brake job. I can't argue new parts wouldn't be better in every case, but IMO, it isn't always necessary to replace the calipers. In fact, I never have and although I've probably only done less then 20 DIY brake jobs, I've never had an issue with a caliper/piston seize.

purevw said:

My concern would be the calipers. I always rebuild or replace them any time I do a brake job, as they often partially seize after the piston position is changed due to new pads. When I worked as an NIASE mechanic, it was considered standard procedure. The brakes may work, but the pads do not fully release the rotor, causing extreme wear and heat.

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David Schaefer said:

OP: How many miles on your Expy?

purevw (NIASE mechanic) - that seems overly cautious and would add a lot more expense & work to a brake job. I can't argue new parts wouldn't be better in every case, but IMO, it isn't always necessary to replace the calipers. In fact, I never have and although I've probably only done less then 20 DIY brake jobs, I've never had an issue with a caliper/piston seize.

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Purevw: that's my plan. If the fluid removal doesn't help, I'll go the new flex lines and calipers route along with a fluid swap to be safe.

David: 168k miles

rwmorrisonjr said:

Purevw: that's my plan. If the fluid removal doesn't help, I'll go the new flex lines and calipers route along with a fluid swap to be safe.

David: 168k miles

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Yes, I forgot the lines. I had that problem with my '94 Ranger. For whatever reason, the line was not allowing fluid to return. Perhaps there was also a delay in actuation, but I didn't sense any. But it did absolutely cause brake drag.

Giving thought to purevw's response about a piston seizing in a brake caliper. 168K miles is quite a few. If it were mine, I'd remove the caliper and note where the piston was. I'd probably mark it with a sharpie. Then I'd carefully compress the piston like I would for new pads. Yours might not go in much. Next, I'd have my wife slowly press the brake pedal, to see if the piston moves up to the line I marked. "hint, very slowly" I would not want the piston to come out and make a fluid mess on the floor!. I would compress it again and repeat, making sure each way is smooth and like normal. After a few cycles, reassemble and go for a test drive. If it still acted like a skid steer, I'd replace the caliper(s), bleed the lines and hope you got it fixed.

Ok, here we go. Just pulled both front brakes off and they're both dragging the rotors. When I compress the pistons, they both work properly and come out evenly when I apply pressure, but don't retract when I let off the pedal. I don't see how both calipers can go bad at the same time, but I could see the lines going since they're OEM. Going to try the lines first then the calipers.

I also found my clunking noise. The MF's at Firestone where I had the alignment checked didn't tighten the right LCA when they had it on the rack, so that's also contributing to the problems! I'll need to find a real alignment shop when this is all done!

The calipers don't retract. The pressure is simply relieved from them and they are free to release as the rotor turns. Some drag is normal. There should be no reason to change them if they freely are pressed back in when replacing the pads and they don't leak.

Some hoses can be problematic. But those too are fine if the calipers release their grip on the rotors.

Trainmaster said:

The calipers don't retract. The pressure is simply relieved from them and they are free to release as the rotor turns. Some drag is normal. There should be no reason to change them if they freely are pressed back in when replacing the pads and they don't leak.

Some hoses can be problematic. But those too are fine if the calipers release their grip on the rotors.

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Thanks for the info. The calipers aren’t leaking and retract smoothly when I compress them. However, they aren’t releasing to allow the rotors to spin freely without a lot of drag. That’s why I’m focusing on the hoses since I moved them around a lot when I did the other front end work.

UPDATE: I tightened up the LCA mount bolts to torque and the nose diving and grabbing has stopped! I also reinspected the calipers and shoes, replaced the slide pin dust boots, verified the calipers are sliding, and bled a bit more fluid out directly from the bleed screw. I did a short road test around the neighborhood and to get my daughter at school and things seem to be working better.

I called Firestone and told them what I found, and they want me to bring it back tomorrow to have them realign it. That’ll be a better road test for the brakes too. Fingers crossed this will be the beginning of the end of this adventure!