Half an ABS??

[Pedro_The_Swift]

I finally got around to trying out Greame’s “power bleed” on the D2,,
And it works like magic!
One minute I have brakes and the next their gone!


A good ¾ turn of the bleeding nipple and the pump pushes fluid through at an alarming rate.
You can hear the difference when you load the pump up to when you release the nipple.
But seriously folks the system works fine IF your Modulator is OK,,
Mines obviously not,,,,
There are 4 outlets on the ABS Mod and two solenoids,, one solenoid controls the Front Pass and Rear Drivers and so on,,
Upon release of the FP and RD bleed nipple I get nada out and the pump runs/sounds loaded,,
Removing and cleaning said nipples brought the same result.
I then bled the FP and RD normally and got half a pedal, (I will re-bleed these today hoping a bigger volume of fluid may cleanse the problem.)

There were NO Amigo lights,, still aren’t. I’ve intentionally activated the ABS on the front left, the dash light comes on but needed a passenger to feel if the pump worked.(will try again today with Mrs Pedro as pump test dummy)

Can I ASSUME the following?

If there is just the ONE pump and the solenoids decide which wheels gets pumped, then the Modulator is OK and its a solenoid sticking problem?
The initial release of brake fluid on both the FD and RP was a horrible dirty black colour,, but ran clean then until the colour changed. I thought there may have been a second black phase as the fluid in the Mod came out---
Otherwise, why would the solenoid stop working?

This all a good thing by the way,,,
With no dash lights there would be no way for me to know I only have half of my ABS until I really needed it,, and even then, I’m not sure if the difference would make itself known,,

I have already talked to some clever people on here but thought a public hearing may bring different ideas.

[Graeme]

There are 4 outlets on the ABS Mod and two solenoids,, one solenoid controls the Front Pass and Rear Drivers and so on,,

Hey Pedro,
Have a look at the ABS modulator schematic in the WSM on RAVE at page 70-13. You'll see there are 8 solenoids, 1 inlet and 1 outlet per wheel. Whilst there is 1 pump motor, there are 2 pump pistons, 1 for the front and 1 for the rear.

I think its purely a coincidence that you have problems with diagonal wheels and probably very lucky not that they're not on the same side, as you could be in strife if ABS kicked-in on 1 side only.

[Pedro_The_Swift]

ahhhh,,,



late edit;

re-bled front and rear "old school" for around 20 GOOD "sets",,

tried the power bleed again and
VIOLA!

brake fluid everywhere

AND,, whats more a GREAT pedal.

am still off to play in the mud,,,,

cant be too safety conscious

[discowhite]

is there a link to Greame’s “power bleed” on the D2?


cheers phil

[Graeme]

Great result Pedro - persistance has paid off! Much better than having to totally dismantle the modulator to clean it out.

Moral - regularly bleed the brakes using the ABS pump to keep the modulator clean.

[Graeme]

Discowhite,
With the ignition OFF, remove the ABS pump relay (engine bay fuse box) and jumper the 2 relay sockets for the thick pins with a link wire c/w spade terminals. An inline switch on wires long enough to reach the wheels makes the job easier. Don't forget to keep topping-up the fluid.

[discowhite]

gee! i was waiting 4 a 10 page essay

cheers phil

[Pedro_The_Swift]

Phil,, just put two spade connectors on the end of a 5 metre length of 4mm twin cable, use a toggle switch on the other, turns it into a single person job,, you will need to refill the res a few times though---
I bought a 4l of brake fluid and used half,,,
but will do this again in 12 months,,