We just picked up our first Volvo: a 1992 245. I'm experiencing an intermittent Brake Failure warning light lately. The pedal is solid (doesn't seem to be the master cylinder), and I can't see any leaks from (what I think is) the junction block. Question is: is the "thing" at the bottom of the two master cylinder brake lines the junction block on an ABS equipped car? I've been having many electrical gremlins, so I figured I'd check for a chafed wire coming out of the junction block . . . but I can't find it. And neither FCPGroton or IPDusa carry junction blocks for 1992 240s with ABS. What's the deal? Is this "thing" an active sensor, or is it just a passive valve?

Does this mean I have a problem with my master cylinder? As an aside: does anyone know the mechanism in the master cylinder that triggers the Brake Failure light?

Please help . . . .

Since none of us has been able to help you as of yet, you might try calling IPD and ask them what the story is with your junction box. Sometimes IPD and Groton can get parts that aren't listed on their websites.

I would also tell them what your problem is, if they aren't too busy they are generally helpful and very knowledgable. Maybe they can help or at least point you in the right direction...

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90 244DL 252K - original engine/drivetrain :)

Bet it's not your junction box unless it's leaking.

It's probably an electrical problem.

I don't have an ABS car so I'm sort of guessing here, but my money is on a bad bulb failure sensor. A fairly common problem with 240's. Check archives (do search) here in the BB for more info. You could experiment and try replacing it (easy, it's under dash below steering column) with a used or new one to see if the light goes out...

For another possibility, check out my response to a post above to a related question regarding warning lights being on. Covers tailight ground/corrosion problems etc....

BTDT!

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90 244DL 252K - original engine/drivetrain :)

" I don't have an ABS car so I'm sort of guessing here, but my money is on a bad bulb failure sensor."

The BFS tests only:
• Head Light Low Beams
• Tail Lights
• Stop Lights

I don't see it related to ABS or Brake Failure Warning in any way.

No ABS 240 on hand, but my '93 940 w/ABS does not have a Brake "Failure" warning light, just a Brake "Warning" light when low fluid level is sensed in the master cylinder.

Since the ABS 240s did away with the 2 separate (dual-diagonal) hydraulic systems, would they still have the Brake Failure Warning switch, which was(?) in the junction block to sense an imbalance between the 2 systems?
That puzzles me.

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Bruce Young
'93 940-NA (current) — 240s (one V8) — 140s — 122s — since '63.

I stand corrected. I was a little confused, think I needed a second cup of coffee this morning! :)

"Since the ABS 240s did away with the 2 separate (dual-diagonal) hydraulic systems, would they still have the Brake Failure Warning switch, which was(?) in the junction block to sense an imbalance between the 2 systems?
That puzzles me."

Interesting question. The original poster mentioned that FCP Groton and IPD don't carry junction blocks for his car - 92 with ABS. That makes me suspect that it is in fact a different junction box. If so, then it probably doesn't have the internal switch that senses an imbalance between the two systems.

Bruce, any thoughts about what's up with this car?

I'm very curious since I know little about ABS braking sytems...

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90 244DL 252K - original engine/drivetrain :)

So, Bruce, what do you think is the problem with the car? Maybe an ABS wiring issue or could it be a MC? Could a bad ABS sensor cause this?

I'm clueless for now. But I'll have a '93 240 here this weekend. Strange that the Bentley '92-'93 diagram (a Volvo copy) still shows the same old junction block switch and warning light -- just like the pre-BS cars(?)

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Bruce Young
'93 940-NA (current) — 240s (one V8) — 140s — 122s — since '63.