Grabby drum brakes as it the first time you step on the pedal at the end of the driveway.After the first stop the brakes are perfect. There's zero contamination on the shoes or drums,all in good shape.I've had a few vehicles that did this. What's the cause?
As a career technician I have seen many causes on both old and new vehicles and will list the most common causes of drum lockup on initial application: (In no order) -weak hardware -adjustment too loose w/ weak hardware -wrong shoes...believe it or not, alot of vehicles are effected by using bonded instead of riveted shoes-the extra surface changes the coefficient of friction and they get grabby for the first app or two. Ever see a Cavalier or Sunfire moving 1st thing in the morning? -I would also check the actual ares of contact between the shoes and drums to ensure a proper arc...Nearly oversized drums with new shoes allow the whole brake servo action to be exaggerated within the drum. (See weak hardware...) -Irregular or improper drum microfinish Hope this helps a little.
Yes it does help.My avatar Willys has a one time initial lockup.It's got a non servo brake,kinda like the GM Huck brake.It has bonded shoes instead of rivited and the return springs looked nice, so I reused them.
living i ny does this, once the rust from sitting overnight is worn off, you're good to go. lol shoe composition plays a big role too, used to have olds C and H bodies back in the early 90's freeze to the drums in the winter time, talk about grabby noise makin sometimes non moving brakes.
It gets driven for a few days,then sits a few days in the garage.I have a long dirt/stone driveway makes the little skid at the end of the drive,both front wheels.Then it's fine.And yes it's noticed after the truck has been sitting for a few days.My wife drives the truck a lot more than I do.She says I always have to "ram" it and then slam on the brakes
The complete braking system is a year old,hoses,master and wheel cylinders,shoes,the drums are round .The brakes don't drag when the pedal is released.it's been damp lately and this might be the problem as mentioned above.
Flash rust on the drums. My new pickup does the same thing in the mornings. Gets a flash of rust on the front disks.
My fifth wheel trailer always did that after sitting a while -- I attributed it to moisture on the shoes but could be flash rust as was said.
My Chevy does the same thing, exept its only one wheel. If it sits more than a few hours it will lock up one time then everythings normal. Kinda sucks when you havnt driven in awhile and you forget about it.
I fought one for a few months. First time out in the morning it would pull to the right like hell. Warm them up by dragging the brakes and it was fine until the next morning. I ended up swapping in some used shoes and all was fine. I didn't worry about what was the problem with the other shoes.
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