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Re: Brake bleeding, rear wheels
On Sat, 4 Jan 1997, Meron wrote:
> subject car is 86 5Kcstq wit ABS
I just did this same car (my own '86 5KCSTQ) Thursday night with no
problems, although I used Brendan Rudack on the brake pedal, and did it
manually. "down - open, shut - up, down - open, shut - up, down - etc..."
> -I rigged a pressure cap to allow compressed air into the MCylinder and
> used 10-25 PSI for pressure
Wow, I had the cap popping off with less than 10psi when I tried this on
my neighbour's 5KCSTQ! I ended up using about 3-5 psi max.
> -the strainer is removed from the MC
> -the MC is full of pentosin
Is this a typo, or are you serious here? If you are serious, then either
you are using Pentosin in the brake system which is a no-no - you should
be using a good brake fluid, not "Pentosin." The other mistake that
strikes me as possible, given this typo, is that you are pressurizing the
Pentosin reservoir, which is for the hydraulic assist of the brakes and
steering, and has nothing to do with bleeding the brakes' hydraulic system.
> -the ABS is turned off with the ignition off
> -the ABS is turned off with the ignition on
> -the ABS is turned of with the car running
> -the ABS is not turned off, car not running
ABS on or off doesn't matter I don't think, does it?
> -brake pedal pushed in (mechanically, via a bar between the seat and the
Ah hah! If the pedal is pushed in, you have closed off the passage that
goes from the reservoir to the master cylinder. The pedal must be up all
the way for brake fluid to travel from the reservoir to the master cylinder.
> -bled the MC, plenty of pentosin from both lines
> -bled the brake lines after the ABS hyd. unit, steady run of fluid but not
> a gayser!
> -moved the lever of the brake proportioning valve lever, no difference
> -bled the brake proportioning valve, very little pentosin
> -looked for a hight sensitive proportioning valve, did not find any
The height sensitive brake pressure regulator is the one on the left rear
trapezoidal arm that has the lever on it. Since this is the only one
with a lever on it, you obviously moved it, but didn't realise exactly
what it was.
> -looked in the Bentley for brake bleeding procedure, NOTHING Helpful
> (looked in two books 85-89 and 89-92 no help
> NO PENTOSIN at the rear with all the above steps!!!!!!!!!!!!!!!!!!!
> front bleed OK (with car off and ABS is normal position)
I'm not sure why you were able to bleed the front. Maybe Achille (who
recently dismantled an MC) might have a clue as to why you got fluid at
the front at all.
BTW, I just put in Stainless steel brake lines, and I bled the brakes
with the new Performance friction brake fluid which has a (claimed)
boiling point of 550 deg F. I now have a very hard brake pedal. As
Brendan says, "Its welded to the firewall!" I had no clue what he meant
when he said this! :-)
Graydon D. Stuckey '85 Mazda RX7 GS, no toys
firstname.lastname@example.org '86 Audi 5000 CS Turbo Quattro, has toys
Flint, Michigan USA '89 Thunderbird SC, lotsa toys