Help me out, from my reading the different post on this i get the impression that if there's a vacum leak(which i've established i do thanks to infidels test)
only the abs/brake light comes on and it doesen't actually affect the functioning of the abs, correct?
my abs doesen't work 99% of the time now. checked it on damp streets. i am also seeing my speedometer jump around occasionaly and a funny 3rd gear shift when driving w/od turned off, which i do mostly if not getting on the frwy. my cruise won't hold a steady speed and accelerates which made me think it was just the vacum prob, but now i'm thinkin speed sensor also.
thanks for any feedback.

john, 95 slt laramie, l/b, auto, club cab, 2wd w/270+k, low stall billet tc, hvy dty tranny, kdp dead, ground stock plate, timin advanced, 235/85/bfg commercials, tc l/u switch, gmc brake fixit, custom leather seats.

 

i had the same problem with my 97. 4wd would kick in as fast, heater controls wouldnt shift to the floor, and when i set the cruise at 60 mph, it would drop to 55 mph then pick back up and hold there steady. traced it out to a vacum line right above the fuel filter, my guess was someone slipped with a wrench or something when changing the filter an broke the line. they tried to patch it with a piece of clear plastic line but when vacum pressure built up the line would collapse causing a shortage of supply. hope this helps