[grendel1960]

the abs light was coming on, so I diagnosed dry solder joints as the issue, I went online and on ebay worldwide there were 3 replacements available. I opted for the uk one at £100 (the usa ones were cheaper, but not after postage) when I fitted yhis part I was dissapointed that it seemed worse than the one I had. nothing for it then, but repair, at least I had mine that worked some of the time as backup.
well I cut the end of the case, spotted the dry joint resoldered all the connectors, and sealed the case back up using a hot glue gun. when tested it worked perfectly.
Solast night I performed the same operation on the one from my car - 2 dry joints on the pump connectors. now resoldered ans hot glue sealed so I now have a spare.

 

[grendel1960]

This soldering fault is a common cause of the ABS light to come on in an older volvo, it has been thought that the process of soldering used to manufacture the boards doesnt leave the joints on the bigger connectors with enough heat to thoroughly create a perfect solder joint, thus over time you get the appearance shown above where the solder looks to have a crack running around the connector. as the part warms up, the crack expands slightly, and this can cause the circuit to break - illuminating the warning light.
my car was usually fine for the first 20 minutes of so, but then if I got in heavy traffic would just blink on, no matter whether I had touched the brakes or not.
You can also get a faulty wheel sensor that would cause the light to illuminate, so look at those first- they should make a circuit when they are ok, if you connect a meter across them and get no circuit, you have a faulty sensor.
If you are not comfortable breaking into the case and doing the work yourself, there are companies out there that do this sort of work.

 

[Vermont]

Ever attempt to use electro-conductive glue (or paste) to make those PCB repairs instead of soldering ?

 

[grendel1960]

to be honest I have all the tools for re-soldering, so, once I have got in there I might as well do a proper job, though I expect the paint might work, but if there is a crack around the post, maybe the paint will just crack again.solder at least adds some mechanical strength.

 

[Ron M]

4 years ago I resoldered the 2 big/main posts (to power connector). This immediately fixed the ABS fault. 4 yrs later after wheel sensor fault code, I de-soldered and then re-soldered all the small solder joints. This again immediatelty removed all ABS fault codes.