What's up with my brakes????
Post by amphi on May 18, 2006, 10:42am

They make this loud deep screeching sound --- like a semi – during moderate to heavy breaking. My truck is very heavy --- nearly 9,000 lbs with the fire equipment and a full load of water (260 gal). It has a vacuum assist break booster and will stop on a dime. You've heard of coming to a screeching halt --- well this does that --- not tires but brake noise. Really loud very deep squeal. Any ideas?

I have pulled all four drums and nothing seems wrong other than worn lining. Not worn completely out but getting pretty close. The thinnest has about 50 to 60 thousands before contacting the rivets. No oil or fluid leaking on the brakes. Drums look good – maybe a little out of round but all four are smooth and shiny.

I marked each drum and put it back in its original location. I can see by the maintenance records the FD has had these off --- I doubt if they put them back as original. What is the reason for this? Why can't they be rotated or moved about?

The shoes on all four wheels are installed with the small (short) shoe to the front. Is this correct?

Does anyone recognize the brake booster pictured? Record show hydro-vac #379776

Here are some pictures.


Right front



Left rear



All look like this



Brake booster


Thanks for any replies
Gary