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240 Brake junction block

TrickMick said:
the Volvo "special tool / bleeder" has a set of chains / straps that bind the bleeder
cap to the body of the reservoir and that assembly to the master cylinder (which
keeps the res from "popping off" under pressure)... :omg:
never had to go that high before - and much more than 25 psi on the MOTIVE style
bleeder and you are running into the "danger zone" where THAT vessel can
EXPLODE (at the seams)...ask your self if' you're ready to remove paint and
staining everything in range of the BRAKE FLUID SPRAY... :oops:

as far as the sequence is concerned - use the one Art supplied (*from the greenbook*)
and you'll have no worries....all you have to do is MISS the reservoir level dropping
ONCE due to all the nipples open simultaneously and you're back at square one...
the "one at a time" method lets you see MICRO bubbles and keep a better rein on
the fluid flow...YMMV
Click to expand...

These Volvo "special tools" are ridiculous. Seems like they were trying to prevent DIY work. More money made at the dealer. Hmm..

Anyway - I may pump the MOTIVE bleeder up to 20 psi, and rebleed the whole system again. The bleeder did run out of fluid once...but I think the reservoir was still very full (close to overflowing). The pedal is quite firm now that I bled it 3 (4 (maybe 5)) times, but it is still going slightly below the accelerator pedal when depressed fully. Doesn't seem right. I think all of the problems are caused by an incomplete bleed.

Could it still be the master cylinder? The pedal isn't sinking slowly as I press on it.

Thanks guys
Mike
 
mtd240 said:
These Volvo "special tools" are ridiculous. Seems like they were trying to prevent DIY work. More money made at the dealer. Hmm..
Anyway - I may pump the MOTIVE bleeder up to 20 psi, and rebleed the whole system again. The bleeder did run out of fluid once...but I think the reservoir was still very full (close to overflowing). The pedal is quite firm now that I bled it 3 (4 (maybe 5)) times, but it is still going slightly below the accelerator pedal when depressed fully. Doesn't seem right. I think all of the problems are caused by an incomplete bleed.
Could it still be the master cylinder? The pedal isn't sinking slowly as I press on it.
Thanks guys Mike
Click to expand...

yeah..hear you 5X5 on the tools...I make most of mine...
the spongy pedal is NOT a good sign...HOWEVER... *IF* you can HAMMER THE PEDAL
with your foot three or four times in rapid succession and then HOLD IT pushing w/a healthy
" HOLY SHlT I'M GONNA DIE " leg and the pedal stays FIRM..then you've "got some pedal"
*IF* it S-L-O-W-L-Y sinks to the floor - it's new MC time :oops:

the FINAL INSPECTION is w/the ENGINE RUNNING *BRAKE BOOSTER HOOKED UP*
and THEN do the pedal test....

FWIW, I just installed a new *GENUINE ATE* brake master cylinder on my 1991 244
(W/ABS)... I "bench bled" the master and got it in the car w/no worries...the FIRST PEDAL
STROKE scared me half to death because it went DOWN DOWN DOWN and then stopped
about an inch off the firewall! subsequent strokes brought the pedal UP and within five
minutes I had "hard pedal at the top of the stroke back"....YIKES! :-P
 
TrickMick said:
yeah..hear you 5X5 on the tools...I make most of mine...
the spongy pedal is NOT a good sign...HOWEVER... *IF* you can HAMMER THE PEDAL
with your foot three or four times in rapid succession and then HOLD IT pushing w/a healthy
" HOLY SHlT I'M GONNA DIE " leg and the pedal stays FIRM..then you've "got some pedal"
*IF* it S-L-O-W-L-Y sinks to the floor - it's new MC time :oops:

the FINAL INSPECTION is w/the ENGINE RUNNING *BRAKE BOOSTER HOOKED UP*
and THEN do the pedal test....

FWIW, I just installed a new *GENUINE ATE* brake master cylinder on my 1991 244
(W/ABS)... I "bench bled" the master and got it in the car w/no worries...the FIRST PEDAL
STROKE scared me half to death because it went DOWN DOWN DOWN and then stopped
about an inch off the firewall! subsequent strokes brought the pedal UP and within five
minutes I had "hard pedal at the top of the stroke back"....YIKES! :-P
Click to expand...

After hammering the pedal a few times then giving it a TrickMick "HOLY **** I'M GONNA DIE" push, the pedal did sink...darn.

I ordered a new master cylinder, with a few cheap lengths of brake line to bleed it with. I do not own a vise - Can I just bolt the new master cylinder onto the brake booster, attach my "bleeder lines", run them back into the reservoir, and pump the pedal a few times to get all of the air out when I install it? Is there any way to avoid re-bleeding the entire system?

Thanks
Mike
 
you will still have to make a couple more trips around the bleed screws, no real way to get around it. that is, unless you're into taking chances and endangering others, i only ask you be well insured
 
mtd240 said:
After hammering the pedal a few times then giving it a TrickMick "HOLY **** I'M GONNA DIE" push, the pedal did sink...darn.
I ordered a new master cylinder, with a few cheap lengths of brake line to bleed it with. I do not own a vise - Can I just bolt the new master cylinder onto the brake booster, attach my "bleeder lines", run them back into the reservoir, and pump the pedal a few times to get all of the air out when I install it? Is there any way to avoid re-bleeding the entire system?
Thanks Mike
Click to expand...

S-L-O-W and *steady* as you "bench bleed" (in the car is fine as long as you don't bend the
"rest of the forest of tubing") :oops:
*if* you've got ALL of the "bubbles out" in your "many times around the car bleeding" you *may*
get away w/o bleeding the rest of the system...it's just the "luck of the draw" now...
keep in mind it's YOUR behind that's at stake if the brakes are flaky...if need be - bite the
bullet and bleed'em all out again...better you should be able to write us you've SUCCEEDED
than for us to find out you've become "road sculpture" ;-)
 
I imagine you could "bench bleed" it that way, but you'd want to have someone under the hood watching for bubbles. Shouldn't take long but you want to do it properly.

But as other said, I would go around the car and bleed each line in sequence. It's not something you want to chance, really.
 
mtd240 said:
... I do not own a vise - Can I just bolt the new master cylinder onto the brake booster, attach my "bleeder lines", run them back into the reservoir, and pump the pedal a few times to get all of the air out when I install it? Is there any way to avoid re-bleeding the entire system?
Click to expand...

I've done this before, but honestly, it wasn't my first time around brake hydraulics. The vise is needed to provide some mass to push against when operating the cylinder against its internal springs. At the time, my vise was about 50 steps away, and I was lazy, so I just held the master in my left hand, and used a #2 Phillips in my right to pump the cylinder until the bleed lines were shooting solid streams of fluid back into the reservoir.

I was conscious enough of the consequences of a slip to turn away from the fender and do this over a table so a spill wouldn't be a catastrophe.

Anyhow, after getting the bubbles out, I would mount the cylinder on the booster and place rags carefully below the fittings, and try to make quick work between removing the bleeder lines and attaching the still-brimming service lines. With the brake pedal up fully, the fluid is free to flow (drip slowly) from the master by gravity, and this will fill any spaces you could leave at the top of the service lines as the flare seals are being made, making it unnecessary (for me) to re-bleed from calipers when only replacing a master. If a line was not carefully disconnected and kept brimming, I suppose one could fill it again by an ever so slight retraction of the appropriate circuit's front wheel piston.

Again, you realize I have a few brake jobs worth of experience to draw from, and part of that experience is the inevitable expenditure of massive quantities of DOT-4 trying to remove imaginary air pockets simulated by spongy new shims and supple new brake piston seals combined with the lack of memory as to exactly how high the pedal was before the whole job was started. I agree, when it comes to brakes, you don't want to leave behind any mysteries.

master01.jpg


master02.jpg
 
Last edited:
Alright here is an update:

I put in a new master cylinder (mid-level aftermarket). Turns out the reservoir was busted already, so I swapped it with my old one. Strike 1. I bolted the new cylinder to the brake booster, attached the bleeder nipples an clear hose, ran it into the reservoir, filled it with fluid and started to slowly pump the pedal. Air bubbles-exactly what I expected. But, no matter how many times I pumped the pedal, air bubbles kept coming out. The brake pedal just goes to the floor now (with foot pressure). Did I do something wrong? I tried using some old brake lines looped back into the reservoir, but the results were no better. Went back around and bled the entire system-no better.

I guess I will have to take the new one back off, attempt to bleed it with a wooden dowel or the like, and put it back on. Any other advice?

Happy thanksgiving by the way


Mike
 
Hmmm... I wonder if it's a bad master cylinder. What brand is it? I always Ate brand as it is OE and seems to be the best quality. Make sure everything is tight. Best thing, if you can get one, is a pressure bleeder. I sell them, or rather, I can get them from one of my Suppliers. They are worth their weight in gold when bleeding a 240 brake system. I have either had no problems bleeding a 240 or massive trouble. I think one trick is to bleed the master cylinder first before hooking the two lines up, then don't tighten them. Bleed it again with the lines loose. Then bleed at the calipers. This prevents air getting trapped in the lines and hard to bleed parts like the junction blocks and warning valve. Good luck!
 
Volvoist said:
Hmmm... I wonder if it's a bad master cylinder. What brand is it? I always Ate brand as it is OE and seems to be the best quality. Make sure everything is tight. Best thing, if you can get one, is a pressure bleeder. I sell them, or rather, I can get them from one of my Suppliers. They are worth their weight in gold when bleeding a 240 brake system. I have either had no problems bleeding a 240 or massive trouble. I think one trick is to bleed the master cylinder first before hooking the two lines up, then don't tighten them. Bleed it again with the lines loose. Then bleed at the calipers. This prevents air getting trapped in the lines and hard to bleed parts like the junction blocks and warning valve. Good luck!
Click to expand...

It is Cardone. I was attempting to save a couple of bucks, but it looks like I should order and ate just to be safe (literally). I have a motive power bleeder, and I love it. I will try swapping the master cylinder out again-advance auto should take the return since the reservoir was broken.
 
mtd240 said:
It is Cardone. I was attempting to save a couple of bucks, but it looks like I should order and ate just to be safe (literally). I have a motive power bleeder, and I love it. I will try swapping the master cylinder out again-advance auto should take the return since the reservoir was broken.
Click to expand...

I have a known good used Ate replacement that was in use 3 months before te car was condemned due to rust... That is if you are interested.
 
mtd240 said:
no matter how many times I pumped the pedal, air bubbles kept coming out.
Click to expand...

Don't just pump away with the lines open. When bench bleeding, you must close the lines when the pedal is on its way up. If you were actually doing this on the bench, you could cover the openings with your fingers before releasing the piston. With the master installed, you may need a helper on the pedal.

I have done it with the lines installed, but loose. You can open one or both, have the helper push the pedal down, then tighten the lines before the pedal goes up. You can tell when air is coming out of the loose fitting, and when only fluid is coming out. Put a rag below the line connections to catch the drips.
 
Update:

Re bled the system several times(don't want to know how many quarts of brake fluid I have used..probable into multiple gallons now). Reinstalled the old MC, no better, and really not all that much worse. Will get an ATE MC in today from Volvoist, and will try it out.

I did find a leaky bleeder on the driver's rear caliper. Would this cause a pedal going all the way to the floor? I would expect just a spongy pedal from something like that. I recently replaced both passenger side calipers, the driver's side may be original (scary). Anyway, I am going to put a new bleeder screw in as a last resort and rebleed- I ordered the driver's front and rear calipers just in case.

I have read alot about jacking up the back end of the car while bleeding, and have been jacking it up higher. What I didn't realize, was that I need to jack up the car by the jacking point, place the jack stand under the AXLE, and then lower the body back down. This prevents the rear proportioning valves from being any higher above the rear bleeder screws. If this is silly logic, or lacking any logic at all, chime in.

I really hope this goes a little better this week - I have spent a pretty large sum of money on brake fluid and parts attempting to revive the brake system. If you guys have any other tips, throw 'em in.

Will update tonight

Mike
 
Thread revival.

I have the car in the air right now, doing a massive amount of work (headgasket, oil pan, diff fluid, driveshaft rebuild). My brake pedal never got any better, even after the new master cylinder. Apologies for the lack of update.

I took a closer look at the rear rotors a couple of weeks ago, and they seem to be pretty lousy. There is a rusty "lip" around the outer edge, where the pads don't contact the rotor. Could VERY worn out rear rotors cause a low pedal? It's not like I push the pedal and it sinks - the pedal just firms up very low in its' stroke. Anyway, I am definitely getting new rear rotors, but wanted to know if there is any way to "check" the rubber brake hoses without removing them? I will just toss those in the same order if I deem them to be "bad". The fronts have already been replaced (spring of 2011).

Thanks
Mike
 
Another update:

Rear rotors, pads, and rubber hoses replaced. All OEM.

The car was already up in the air with all four wheels off, so I flushed the whole system with nice ATE brake fluid, and the pedal STILL travels all the way close to the floor. What gives? This makes me want to put the car in the shop to have the brakes bled - I feel like it should be very simple with the power bleeder hooked up.

Anway, I will try the "ass in the air" method again tonight and hope for the best. I am literally dumping money through my brake lines right now - easily over $100 spent in brake fluid.

Another question - a failure of the brake booster, check valve, or booster hose would ONLY result in brakes that are harder to push? That seems to be the only component I haven't fiddled with.


Mike
 
get some *OTHER EYES* in there w/you....you're missing something basic or there
is a problem that you're not aware of (when you find it, you'll be gob-smacked!)...this
is one of those grab a dude / dudette that KNOWS and have them lend a hand....FWIW
my last brake master install was one of the deplorable GM "17 degree tilt" masters that
give techs a fit...we went thru 2 quarts of fluid before we got all of the "hidden bubbles"
out of that system....(and we DID "bench bleed" using the factory method)...it was
"just one of those things"..aaarrrggghhhhh
your system has to be *AIRTIGHT* (fluid seeps will only evidence themselves after stress
and if you're not making good LINE PRESSURE that "indicator" won't show itself right away...
this is the tool I use @ the shop to confirm LINE PRESSURES:
http://www.toolsource.com/brake-pressure-test-p-51210.html
if you find a shop that uses it you will find your $$$$ well spent for the testing *AFTER* you
confirm all of your bleed nipples are seating and the hose are sealed tight, etc....
 
Okay the back end is up in the air, gonna give it 2 hrs or so then I'll bleed again. Thanks for the advice trickmick-I am scared of what obvious thing i am missing. Ireally should have a pro mechanic with me at all times with the amount of mistakes I make. I don't really know anyone that could help though

Anyway, when I push down the pedal (car off, all booster vacuum diminished), and press the brake pedal, it sinks about halfway while putting out a rather loud "honking" noise, then the pedal stops solid. Is this a bad booster? Would this cause brake problems like mine?
 
things i found most beneficial

fluid added to Motive and then let it sit a while to let the suspended air out

higher pressure in the Motive, to propel or catch the trapped air with the additional oomph

make a few rounds around the car and pump up the pedal between rounds.
 
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