So I've been having this problem with my trucks brakes for what seems like forever now, and a while back I talked to a team lead tech at a local dealership. He quickly diagnosed the issue as being a failed ABS pump, which is apparently common when my truck's symptoms are present.

I've done a ridiculous amount of research on the web, and found a few interesting things. There are a number of different pumps. What pump your truck has on it has to do with what rear brakes you have (ie rear disc vs rear drum), 2wd vs 4wd, 4 wheel ABS vs RABS, etc.

My truck is a 98 half ton w2/ RABS. Needless to say, I haven't been able to find the right pump, or even the part number for it, within a reasonable price range. Finding a used one seems damned near impossible. I don't have $400+ to be dropping on a freaking pump, so can somebody at least point me to the correct part number, or god forbid, somebody who might actually have a good used one to sell for a decent price? My poor old truck would be eternally grateful.