Disco 1 - rear brakes won’t bleed

[bsa_m21]

Any gurus out there on bleeding D1 brakes?

I just replaced my rear calipers and disks. I then followed the manual directions for bleeding, but nothing comes out the rear bleeders. So I started checking the brake lines to the abs modulator and pressure reducing unit (pru). Lines from the abs to the rear calipers are clean and I can push fluid through them after I disconnected them. However it seems there is no fluid coming from the abs to the rear lines. Circuit Diagram seems to show flow goes from m/c to abs to pru back to abs then to the rear calipers. Something in the abs or pru seems stuck.

Any suggestions appreciated.

[rgallant]

Hi Martin, could be the master cylinder feed line from to the ABS pump. A fellow on another forum had the same issue, he pulled the feed lines one at a time at the ABS pump unit to find it.

[bsa_m21]

Well it turns out the pressure reducing unit was rusted solid internally. Although I changed the brake fluid when I got the truck, 2 years ago, who knows if it was ever changed prior to that. I ended up disconnecting all lines and blew them out with compressed air, pulled the m/c reservoir and spent an hour cleaning Inside it, and found that the PRU on my “frankenrover” build was still good, so used it on the reassembly. Will have to get another one to replace it down the road. Bled the brakes and all is good now.