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replaced all calipers and pads on a 89 245 with 196k km, pedal does not hold after 2 bleeds. Replaced master cylinder and a couple front hoses. Rebled twice same issue with pedal, left it for a day and rebled 3 times. Same issue with pedal. Have brakes but only at bottom of pedal travel, Could use some input on a solution
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It does sound like you may have got mistakes in the reman of a front caliper or two. I'm guessing you didn't intend to replace the master first go-around, but did after failing to bring the pedal up with the new calipers and bleeding.
Check to see if there are matched dimples at the bottom of the front calipers. Bench bleed (in a vise or on the car, either way) your new master. The 89 uses the differential pressure sensor in the octopus to light the brake failure light, but it doesn't cause brake symptoms. This "feature" was done away with on ALL '91s, not just those with ABS.
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Art Benstein near Baltimore
Do plumbers who become electricians install outlets upside-down? Hot on the left?
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Started with replacement of rear calipers and pads, then while I am there......
Found a leak in new rear caliper, cross threaded bleed valve, thanks Raybestos
Will bench bleed master when I get fitting for the outlets that allow attachment of hoses
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Back when these cars littered the pick'n'pulls parts like a hunk of the correct brake line to make a bench bleed kit were easy to collect. Not sure how one would go about that now. Perhaps the local auto parts vendor has the answer.
Speaking of things changing, I just received my second set of reman front calipers which to me look new, they're so shiny. The tell-tale punch marks are nowhere to be found. I have to check the assembly was done correctly with a bit of compressed air and a block of wood.
Been a month. How doin'?
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Art Benstein near Baltimore
"To me "drink responsibly" means don't spill it."
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"replaced all calipers"
Look for posts by Lucid regarding mismatched caliper halves during rebuild. Basically when the calipers were disassembled and rebuilt, left and right caliper parts got mixed up making the rebuilt caliper impossible to bleed.
You also haven't mentioned the bleed method you used. Pressure bleeding seems to work best. The main part is a brake reservoir cap that has a tire valve installed. It allows you to apply pressure while you go around bleeding the calipers.
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1980 245 Canadian B21A with SU carb, M46 trans, 3:31 dif, in Brampton, Ont.
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thanks for the replies. I usually work on the basis of not having time to do it properly but plenty of time to do it over...... did not bench bleed the master, peddle pressure after bleeds but none when engine started.
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My thoughts are the same as Trev29. Mismatched front calipers, I've been through that before. The calipers should have a dimple stamped into each half near the end of the disc slot. They should be next to each other. If only one has a dimple, and the other one is at the opposite end of the caliper, that's a problem. The halves were mismatched during the rebuild.
If you have a way to safely clamp off both hoses to the calipers one side at a time. Then test, to help locate the problem.
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Bruce S. near D.C.
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When you press on the brake pedal, does it go part way down, hit resistance, and then settle down to the floor? Or when you press the pedal does it sink straight to the floor?
A couple possibilities:
You may have a poorly rebuilt master cylinder. There are plenty of sketchy ones being sold. I bought one a few years ago from either Advance Auto or O’reillys and it was missing some of its internal pieces.
The rod length may be wrong between the booster and MC. Too short and the pedal has to travel too far down before it starts to push fluid. Too long and the piston doesn’t fully return home to allow fluid to drop from the reservoir down into the cylinder. Did you compare the old MC vs the new MC to see if the pocket on the rear of the piston is the same depth (measured from the MC-to-booster mating surface)?
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Hi,
In reading another post ...
Ok ... that sounds very plausible to the extent the split circuits are tied together there a JUNCTION BLOCK.
I have thoughts for, that it's all it is, a convenient junction point, down low for a reason.
But leaking, how do you test for that?
Sorry I don't see it!
I may be going back too far, in model years, but the term "octopus" use to have sliding piston inside it.
The piston inside there was a switch mechanism, that shifted.
Thus item that tripped on the service brake light on to warn of a compromised brake system.
By the 1991 years, because I own one, a newer switch appeared up in the master cylinder reservoir.
This switch, I assume, is a brake fluid level warning light.
I do not know, again, if the master cylinders are different internally by piston size?
I don't know again, if the two circuit safety system, is Or was, still being used.
They were big on that safety idea years ago.
The upper sides of the front calipers do get bled last. As the theory goes, the shortest lines are bled last, because air rises, when any heavier fluids are stagnant or heated.
I don't know about the 1989 but in 1991, the ABS system was "A" possible "optional" offered item.
The sun roof was too!
The 1989 was probably safe from getting messed with! Production Ru Canges are always done, as they say, within their disclaimers, except for the dealer service bulletins, a year later!
Be glad you don't have tons of electronic software!
I gather you did not have any issues, with a low pedal before, but only weaker brakes than your friends car? With your extra work now, I see why the expectations have dimmed!
I agree pads with other posts of what can affect performance. A flow restriction should have been cleared that up with new lines.
Seems puzzling to me unless, the "push rod" on the new cylinder is way short. That might lower the pedal.
This rod from the master to the booster is critical and it "Must not be too long" so it releases fluid back into the reservoir. You are only allowed "up too" .030 play on the rod.
Most rebuilt cylinders have warning papers to check that clearance during setup.
But nothing really changed with this puzzle from what you are saying.
The difference in effort to stop the car could be a difference in the vacuum boosters power very easily.
They are a PITA to unbolt it from under the dash, so unless, there is a performance test for booster strength, think twice! I changed one once to find almost no difference. The "Over Thinking" process can hurt ones pride!
I have read that sometimes the halves of calipers get put on upside down or shared backwards.
They say there are punch marks on them that need to be together.
You might look for punch marks to be aligned correctly at the middle seams.
Maybe they're not bleeding or getting the "applying juice" correctly!
I have never seen this myself because I have very little experience in replacing calipers.
I do know my days are coming despite some decent maintenance on my part.
Let's us know what you scraped up!
Phil
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I was working so I didn’t have time to elaborate.
“Ok ... that sounds very plausible to the extent the split circuits are tied together there a JUNCTION BLOCK.
I have thoughts for, that it's all it is, a convenient junction point, down low for a reason.
But leaking, how do you test for that?
Sorry I don't see it!”
BTDT - You are wrong about this. I had to replace the block on my 90 244DL many ago. I had the perpetual 240 low pedal after replacing the MC and repeated bleedings. It was hard to find but it was leaking externally through the switch. There are seals on the switch and on the floating mini-piston inside that both can leak. Had to replace the block to fix the low pedal....
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Will I buy another Volvo??? We'll see....
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Hi,
I said I might be screwed up on knowing the particulars on the octopus block.
So you are saying the brake failure switch is still on these cars of 1989 or later vintage
Ok!
Phil
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It is on the 89 and 90 240’s. Not sure about the 91-93’s with ABS. Been awhile since I owned a 240 so I don’t think about them as much anymore.
Jim
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Will I buy another Volvo??? We'll see....
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Hiya Messrs Machine Man and Walker!
ABS does not have a junction black with the BRAKE light sensor between the primary and secondary brake circuit.
ABS merely has a brake fluid level sensor and so a BRAKE light on the dash when the brake fluid is low.
Arty B. had to point the obvious for me in a message 'cause I was not getting it while staring at the 1992 and the ABS brake fluid sensor on the brake fluid reservoir!
D'oh!
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Beh.
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How do Kit!
Hope all goes well! Thanks for the ABS description. Makes sense - Interestingly, as I remember, that is identical to my now departed 95 855GLT as well. As I recall, the ABS brake system is actually simpler than the pre-ABS system. Fewer parts. Now I’ll have to check my VW too...:)
Did you get that job you were talking about? This pandemic is killing my business! Hurting a lot of people. At least I have my health except for a damn broken wrist that needs surgery. Oh well, life goes on...
J
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Will I buy another Volvo??? We'll see....
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Hiya Mr. Starkie!
A hearty happy Friday! Well wishes that everyone is safe, happy, and healthy!!!
Brakes are cool. I like stopping far more than going when motoring!
That Motive brand power pressure bleeder is the trick!
That is until the clear vinyl line between the Motive pressure / new brake fluid reservoir and the brake fluid reservoir bursts! Yet to get a replacement line. A merely 20 PSI!
Yep, three months in and they have not kicked me out. Sort of a hard start after the unwelcome idle time. All that brain plasticity stuff.
My price to earnings ratio is terrible. Debt versus holdings. I'd suggest againts buy my stock! Ha-ha!
I'll buy stock in your business! I'm sorry your business has slowed. If I can help with anything technical writing and illustration pro bono, please lemme know.
I need to do a full brake service on the grey 1991 sedan. Best brake job I've done. Lasted over a decade. Yet not many annual miles.
Hope you, Mrs. Starkie, the family, yours, and pets are all safe, happy, and healthy!
Back to work!
A very Merry Happy Friday! We can also call it a happy Sat-Your-Day eve!
Sorry to be late in responding.
For tomorrow is:
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Beh.
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Perhaps it is a non issue after so many bleeding attempts, but did you bleed the master cylinder prior to the normal sequence of bleeding at the calipers?
If not that would be my suggestion.
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Any twenty minute job is just a broken bolt away from a three day ordeal
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Have you checked for a leaking seal inside the octopus aka the front junction box?
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Will I buy another Volvo??? We'll see....
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