2002 s60 No fluid flow from ABS to Caliper

Post by **FLXC90** » 26 Dec 2014, 07:30

Those are activations performed through the VIDA/DICE connected to the car.

Post by **jimmy57** » 26 Dec 2014, 08:03

It's messy and you should wear eye protection: Have someone sit in car with key on so elec vac pump will work for brake booster to work. Break the line loose at master cylinder for the circuit affected and then snug it back. Have the wrench on that line postioned where you can move it 1/4 turn or more. Have the bleeder screws open on the blocked circuit when you do this.
Have assistant apply brake pedal hard and then you pop that line open 1/4 turn. Repeat this.
Often this will create enough pressure "shock" to free up the valve.
This isn't always successful but it going to cost you only the lost brake fluid.
If it works then bleed the brakes thoroughly.

vmaxmike · Post by **vmaxmike** » 26 Dec 2014, 09:15

FLXC90: No special bleeder, just an assistant at pedal and me with wrench. There is a bleeder tool I saw on ebay that pumps fluid into the caliper and up the line...it specifies not for abs systems but in this case, it might be worth a shot. Removing the elec module reveals the 12 solenoid valves but they are sealed steel tubes, so nothing to finagle.
Jimmy57: Thanks, I've already had the abs pump off car and on my bench with all fluid removed by inserting rubber hose and blowing it all out. Interesting how on the clear circuit (in line from MC) i could push and draw air both ways easily but on the other one, i could suck/draw air out but could not blow in as if a one way valve was preventing it. Its all back on car now but with no change so I will give that procedure a shot. Wish I knew which pins on the ABS module control LF and RR wheel solenoid valve operation, i could test them with direct voltage.

Post by **FLXC90** » 26 Dec 2014, 09:34

Regent, do you have a pin-out or schematic of the ABS pump that you can post to assist OP in troubleshooting?

Post by **FLXC90** » 26 Dec 2014, 09:43

I don't know which way the plungers open or close, or where the current runs to operate them. If you remove the electronic module, perhaps you could place a magnet on the end of a plunger tube to unseat a valve? Pretty weak guess, but it would be free! Other than that, all I can think of is rebuilding/replacing the ABS hydraulic unit.

Post by **FLXC90** » 26 Dec 2014, 09:58

Revisiting the part with compressing the caliper, but no change in the reservoir: If you haven't already compressed the rear caliper, make sure the line is full of fluid before compressing. try this if necessary, disconnect line at ABS, use the bleeder vacuum tool at the caliper, dumping waste fluid into a bottle, connect ABS end of line to a supply of fluid, open bleeder and draw fluid through until clean fluid appears at caliper end, then you can connect lines and compress caliper to observe reservoir.

Post by **jimmy57** » 26 Dec 2014, 22:59

The solenoids are not wired through connector. The solenoids are integrated with the module so they are wired direct from the circuit board.

vmaxmike · Post by **vmaxmike** » 28 Dec 2014, 22:09

I had previously already compressed caliper on both wheels not realizing air was present so decided to install circuit #2 brakes lines going to abs pump into the circuit #1 holes that have flow, bleed those lines and managed to press caliper pistons back out and beyond with pads removed! Then I switch lines back to proper holes, and compressed rear caliper all the way back in and saw fluid level raise in the reservoir! Tried then to pump pedal but it was firm and absolutely would not budge the piston back out. Still need to try this on the LF wheel (doubt it will be any different) and also try Jimmy57's "shock pressure" suggestion. I did get a response from Matty Moo but long story short nothin doing there. Keep you posted! Thanks.

Post by **regent** » 30 Dec 2014, 08:05

Sorry for my late response,
Pinounts I do not have. Like jimmy57 indicated, pinouts would not do much good because the solenoids are driven internally by electronic switches within the module PCB.

If you do not have access to the VIDA DiCE setup, then the "Shock Pressure" approach will be your only other 'cheaper' option. Hope you tell us soon that it worked

Notes (you probably know all this already):
1. When you bleed the system, if you use a power bleeder on the MC Reservoir, make sure you do not exceed 15 PSI.
2. When you pump the pedal to bleed, place a 1-inch shim between the floor and the pedal to limit its travel.
Good Luck!

Post by **FLXC90** » 30 Dec 2014, 11:58

Not to hijack, but to learn; why the spacer, will the pedal overtravel and draw air in the backside, or cock a piston or something?