yardpro

dr bob.
can you go into more detail about how you hook up the vac to the abs pump?
wer you screwing in nipples where the lines hook in?

worf928

+928.

I also have a plastic dead blow mallet that I use to tap the calipers to dislodge air bubbles. Light wacks at about 2hz on the side of the caliper where it won't bend anything will get you a stream of bubbles.

5 PSI is sufficient. You can go higher if you've got an auto or if you know your blue hose is good if you've got a 5-speed.

But, before you do anything else, make sure your chasing the right problem. There are plenty of threads on diagnosing brake issues. In particular find the one started by Nicole.

dr bob

I actually did it from the MC end of each line that runs to the ABS unit. I have some 'vintage' ATE bench-bleed fittings that fit the ABS OK, but they had clear vinyl hose attached and that collapsed when vacuum was applied. I could have swapped in some vacuum tubing/hose, but it was easier to just slip the vacuum hose over the ends of the pipes at the MC end.

Fair warning -- I spent the best part of a long day doing all this. And my brakes were 'OK' when I started. I just figured that, while hoses were being replaced and system was going to be flushed anyway, it would be a good time to get the fugitive bubbles out. It took a lot longer and more effort than I originally anticipated. Part of the time was rigging the vacuum pump with vacuum T's and the catch bottle (part of my hand vacuum pump kit...). Some was initially getting a air-powered vacuum set up. In the end I used the 4-stage lab pump I use for AC work, and had to rig up the connecting plumbing for that.

If I didn't have the vacuum setup, I would try connecting bleed lines from the front of the ABS unit, and doing a normal pressure bleed from the master (after bench-bleeding the master). Then pressure bleed backwards from each wheel hardline end uphill through the hard lines to the ABS end. Then pressure bleeding the normal way to refill the calipers. You can buy short lengths of the steel line from local parts places, to cut and connect to hose or tubing. Clear vinyl hose from H-D works OK one time with brake fluid, and allows you to see bubbles and fluid flow as you push fluid and air around. Regular vacuum hose (local parts store) is handy for this too, and is easily pinched with hemostats to seal things up as you move from line to line, section by section. None of this is rocket science, it's just remembering which way is uphill and always pushing fluid and air in that direction.

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Nicole had previously shared some info on chasing a more severe soft- and low-pedal problem she'd had with her car. Bill Ball and others had been fighting it for a while, but it was to a point where she felt the car wasn't really safe to drive. Ultimately it ended up at a specialists shop in the Bay area, where they were able to get it all working with some vacuuming IIRC. She followed up with this after contact with someone she knew with knowledge of the original factory fill methods with vacuum. She gets a lot of the credit for sharing her experience and the info from her contacts. Without that I'd probably still have the soft and slightly low pedal.