2005 xc 90 front passenger brake locked up

[Dale Large]

This is a cont. from 2005 xc90 front wheel locked up ..........!!Hey my Volvo buddies spend hrs. going through bone yards today as these places are poorly organized sometimes.. came up empty handed and found a big scarlet king snake in a trunk (did not harm him) My real question is I think my BMC is ok and also pretty sure my ABS pump is fine. What block(hydraulic} or ABS distribution block{not sure of correct name} can I use I see many xc70 ? that look just like the same part off my xc90 not sure if I can use them.. I really need some help here by someone smarter than me on Volvos ? I hope I described this well enough / If not I will explain in more detail.. I do have the DST button Traction control deal ? I have really had my butt cut on this ..
please some one help me. This stuff is so so high dollar and this is no show car but my disable wife's : only ride, need help !!

[Dale Large]

Moving forward !!!! Ok my BCM good my ABS pump good The ABS distribution block looks like it is the problem ?? This is where I need some Volvo knowledge boys ! I have been to a few bone yards can not find same year set up ? I see many many ABS blocks from xc70s or differant years xc90s but they look the same being I am {only swapping the block out}What style or years can I use ?? I do have the DSTC option may not make a difference ? This is what I must know to end this "Bad dream" of a repair ! Thank you to anyone who will try to help !!

[oragex]

People seem to replace the abs valve module with the same number stamped on it.. . I'd suspect the underneath electronic module will then match as well. The donor car has to have DSTC as yours. For the rest, XC70 or XC90 can't answer.. sometimes Volvo uses the same parts, I'd just make sure to match the numbers. You may as well try just replacing the valve unit and motor and keep your electronic module - a bit tricky to separate the two. The brackets and electric connectors that keep the whole assembly are also quite tricky to figure out how to undo.

[mrbrian200]

We really need to know the root cause of this (abs valve block acting like a 1-way check valve). Somebody in engineering needs to pick one of these failed units apart and figure out what goes wrong. This is NHTSA recall territory: this shouldn't be happening under any circumstance. A partial brake lockup after touching the brakes at speed could result in loss of control, injury or death.

[oragex]

My wild guess is sometimes the issue is caused by installing new brake pads without opening the bleeder. Forcing the piston back to make place for the new thicker brake pad. This may knock off one or more solenoids inside the valve body. I have read on two instances - sorry, don't have the links - when this affected the abs valve body: once replaced the brakes worked well again.

Most of us bought the car used.. we don't know how mechanics worked on the brakes in the past.

But there may be more causes, such as perhaps solenoids getting stuck because of worn bushings much like inside a transmission valve body.

The pump that sits on top of the abs unit can also be faulty (worn brushes maybe because some short causes the pump to keep running). Finally, the electronic module can also get fried.

http://forums.swedespeed.com/showthread ... the-module

[cn90]

My 2005 XC90 2.5T with 132,840 miles...

The FRONT brake (both front brakes) locked up.
I had to stop the car in a shopping mall parking lot.
About 20 minutes later, it is OK.
Or maybe when I put the car in REVERSE, it solved the locking up issue, idk.
So this is a trick that might be useful: if your front brakes lock up, pull over to a safe place (shoulder of hwy or parking lot)..put it in reverse to see what you get.

I am now thinking it is from a bad module.
But why does it activate only the Front brakes x 2 only?
Is there a circuit that activates both Front brakes?

[cn90]

Does anyone know the fuse for ABS circuit?
I am thinking about pulling the fuse...

No ABS feature is still better than random wheel locking up!

[cn90]

Sometimes, I wonder if this could be an issue in the input side...

What if the wheel sensor(s) say the front wheels are slipping on ice/snow (when that is not true), the ABS Module sends a signal to brake the Front wheels...

Just a thought...

[cn90]

Found this reply by a mechanic on "Justanswer.com"...

Volvo Mechanic: Eric

"It could be that the brake hose has collapsed because of the brake fluid in the caliper and the hose boiling due to the caliper locking up, or it might be an issue with the ABS hydraulic unit related to the internal solenoid for the front driver's brake.

You can take out the fuses for the ABS unit and go for a test drive. If the brakes still lock up, you should replace the brake hose. If they no longer lock up, then the ABS hydraulic unit will need to be replaced..."

[abscate]

I doubt it is a bad hose. Bad tone rings will definitely cause abs faults. If you have a fault in the ABS module you will almost certainly code. I think I would try bleeding 500 ml per caliper to test for the hoses and it’s just good practice.

You could have calipers that are both sticking , too. Does the beast get daily driven or has it been sitting?

I’ve got a 2013 so I’m not sure my fuses map to your 2005

I went to look at the 2005 manual online but couldn’t find it on the web anymore…has that changed?