Grabby front brakes, what to check first?

[HotWheelsBurban]

No it's not pulsing, it's just grabbing right at the end of the stop. Enough you can feel it in the floor. Didn't get to mess with it today, the Burb needed the oil and filter changed (way overdue) since we have to drive it all over Houston tomorrow.
Went to move the big truck, and...it wouldn't start. Stupid sunvisor light was on,and ran the battery down. So...after the toy and diecast show Saturday, I'll see if my buddy can get next to it in the driveway with his Colorado and jump start it. Then I can get it in the other driveway, so I can jack it up, get a wheel off, push the pedal and see what it does.

 

[someotherguy]

No it's not pulsing, it's just grabbing right at the end of the stop. Enough you can feel it in the floor. Didn't get to mess with it today, the Burb needed the oil and filter changed (way overdue) since we have to drive it all over Houston tomorrow.
Went to move the big truck, and...it wouldn't start. Stupid sunvisor light was on,and ran the battery down. So...after the toy and diecast show Saturday, I'll see if my buddy can get next to it in the driveway with his Colorado and jump start it. Then I can get it in the other driveway, so I can jack it up, get a wheel off, push the pedal and see what it does.

Those visor switch arrangements can break and leave the lights on full-time. If the lights aren't important to you, the easiest fix is to pull the screws for the visor so you can get to the harness and simply unplug them; there's a disconnect right there inside the hole in the roof.

For me, grabby brakes always point first to bad flex hoses, but the other tips about being sure the slide pins are properly lubed and not gummed up would be an easier, no-cost thing to knock off the list first.

Richard

 

[HotWheelsBurban]

Those visor switch arrangements can break and leave the lights on full-time. If the lights aren't important to you, the easiest fix is to pull the screws for the visor so you can get to the harness and simply unplug them; there's a disconnect right there inside the hole in the roof.

For me, grabby brakes always point first to bad flex hoses, but the other tips about being sure the slide pins are properly lubed and not gummed up would be an easier, no-cost thing to knock off the list first.

Richard

That's what we did on the visor, had to do that on the Burb a good while ago.
I would not be surprised if this thing needs a full brake job, but I will look at the easy cheap fixes first. It still stops well, it's just that this grabbing is annoying and I know it's not supposed to do it.

 

[Pinger]

The 'grabbing' - is it a refusal to release the brakes as you lift off of the brake pedal and the truck should come to the last bit of the halt due to its rolling resistance, or an increase in braking effort at the end of the stop when you still have your foot on the pedal?

Early 1980s 3-Series BMWs were prone to the former. Lifting the brake pedal to release the brakes in that last few feet of stopping would see the brakes remaining applied and an abrupt stop ensued. Followed by the nose of the car leaping up after the nose dive I was trying to feather out of the brakes to avoid. They all did it (I drove loads - I was working for Hertz at the time) but GMT400s don't -or mine doesn't - or your 'Burb.

For me, grabby brakes always point first to bad flex hoses, but the other tips about being sure the slide pins are properly lubed and not gummed up would be an easier, no-cost thing to knock off the list first.

Richard

HWB is well versed in bad flex hoses!
Agreed re a quick run through the caliper to 'knock off the list' - then a dive into the rears?
I suspect (if the hoses are OK) a self servoing effect which the rear brakes are more susceptible to than the fronts. There is a very slight self servoing effect possible with calipers - less likely with worn pads though. Or wet/contaminated rear shoes - unless absolutely the problem is at the front end.

FWIW, my slide pins had to be hammered out. But the brakes still worked OK, both pads in each caliper being brought into play. My guess is the pins were just free enough (or possibly relying on the elasticity of the rubber bushes) for the very small movements required for brake operation but beyond that narrow travel - solid.
They 'feel' much better now but I haven't had a decent drive yet (village and back a few times is all) and as there were new rotors and pads fitted and I got the rear shoes properly adjusted (possibly for the first time in my ownership) it's hard to assign the difference to any one thing. For sure though sliders are supposed to slide...