89 240, Just replaced the brake master cylinder, now the (8 line) distribution block is leaking. Could a new Master (with nice strong pressure) cause the block to leak or just concidence? Thanks! Dave

 

Volvo recommends replacing both at the same time. Unfortunately, a leaky junction box can't be fixed by just replacing the switch. The seal on the switch is a dust seal not an oil seal. I assume your brake warning light is on. Replacement of the junction box is indicated. Not a fun job with eight hydraulic lines.

 

Blue- No, the light isnt on, It was on a couple of months ago, replaced the master and its been off since. Just noticed the fluid level in the res low, topped it off and was low again a couple weeks later. dry at the wheels, saw block was wet. thought First I'd dry off, crack and tighten the line that looks like it's leaking. But why is it now leaking? I never touched it! Now back to those ball joints...

 

OK, no brake warning light so the internal piston hasn't tripped the switch, maybe the junction box is good. Maybe a leaky connection to one of the lines. I'm thinking that when you replaced the master cylinder you may have flexed one of the lines and stressed it at the junction box. I hate it when a hydraulic line leaks.

 

Yeah, thought I'd try to loosen then tighten the leaky one (or others). the installation was pretty simple, seems hard to beleive I flexed on of those...D