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56pan
12-02-2018, 05:34
My son's coming home for a few weeks and I need to get his 2000 K3500 single rear wheel truck ready for him to drive. 350 gasser. Last Christmas we replaced a rusted through rear brake line and I've never bled it yet. I'm sure air has migrated up into the ABS module up under the master cyl. All info on this model that I can find indicates that I'll have to have a scan tool to do the ABS module autobleed. I've got a good OTC Genisys scanner that I bought years ago, but the software update kit is ~$790 and that dog won't hunt. The GM Tech II is pretty is expensive, even used. I don't have the wiring diagrams yet, but can I not command the ABS pump on and operate the valves from the ABS module connector? Or does it have to be done as per some autobleed sequence? Any advice will be appreciated. Thanks.

Yukon6.2
12-02-2018, 11:11
Hi
The last time i did the brakes on my 98 3500 4x4 i just let gravity do it's thing.Seemed to work fine for me.
I started at the furthest wheel from the master cylinder,and opened the bleeder and waited for the fluid to come out,then moved to the next.I had changed both rear brake cylinders when i replaced all the shoes.
Seeing i work alone i thought i would try it and it worked for me.

DmaxMaverick
12-02-2018, 11:31
It isn't as complicated as the service manual suggests. The repair procedure was written for use by tech's in a GM (or compatible) shop. The scanner-commanded bleed procedure accommodates repair time and shop abilities.

Simply (and better, IMO), just make sure all the parts are in place and connected properly, and fill it with brake fluid to the full mark. Go to a dirt/gravel (or snowy) road and do several runs to 20-30 MPH, and brake hard. The ABS should activate (and the ABS lamp should come on, at first). Check the fluid level between runs. Once the fluid level remains full after 2-3 runs, it's bled (important! the air travels AFTER braking). If the ABS lamp stays on, repeat until it stays off (key cycle between runs restarts the diagnostic process, or use a capable scanner to clear history). Typical is about 4-6 runs, but I've never had to do more than about 6-8.